DEPARTEMENT SIGNAL ET TELECOMMUNICATION

Transcription

1 DEPARTEMENT SIGNAL ET TELECOMMUNICATION Réseaux Hauts Débits Réseaux Optiques 5 ème Année B IRT Stephan ROULLOT

2 Agenda Cours Réseaux Optiques Partie I - PDH, SDH, Carrier Ethernet, FTTx Stéphan Roullot Alcatel-Lucent Optical Networking Division [email protected]. Introduction Alcatel-Lucent. Transport Protocols in Public Networks. Multiplexing techniques 4. PDH Overview 5. SDH Overview & Advantages of SDH 6. Basic SDH Frame Structure and Transmission Principles 7. SDH Multiplexing Structure 8. SDH Pointer Function 9. Overheads 0. Synchronization. Protection Mechanisms : MSP, MS-SPRING, SNCP, DNI, hardware. Classification of optical interfaces & Transmission Range Cours Réseaux Optiques Partie I March 008 Agenda. Functional Equipment Specification 4. Typical Equipment Types & Network Applications 5. OAM&P 6. ASTN / GMPLS 7. Standardization 8. Conclusion on SDH, evolution to Next-Generation SDH, MSPP 9. Native Ethernet 0. Example of prolonging SDH life: Ethernet over SDH,. Recent developments around Carrier Ethernet Technologies. Transport Network Evolution. FTTx 4. Overview Optical Market & Competition Introduction Alcatel-Lucent Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

3 Lucent Technologies History Lucent Technologies spun-off from AT&T in 996 Acquired PKI, TRT, etc in Europe Manufactures equipment for telecommunication networks Transmission, Switching, Wireless, Data, Access, IMS Bell Laboratories ~5.000 employees world-wide France (00 employees): Le Plessis-Robinson, Lannion Formerly TRT Activities: Wireless R&D, Marketing & Sales, Support Services Optical Networking Group (~600 employees in R&D): R&D centers in the USA (Holmdel, Westford, Whippany) for SONET, DWDM equipments, and Germany (Nürnberg) for SDH, OC equipments Manufacturing outsourced in China Merge with Alcatel effective December st 006 A Portfolio of Wireline Solutions at the Forefront of IP Network Transformation Enterprise UMTS/LTE CDMA DSL Residential Broadband PON WiMA Next Generation Wireless Intelligent Transport Universal Access NG IP Base Station Service Aggregation Federated Control IPTV IMS Web Policy-Driven Subscriber and Resource Management Service Edge Gateways, Mobility HA Converged Network Scalable service delivery across resilient, IP-rich Infrastructure Distributed per-subscriber and per-service control PSTN, ISPs, Peer IP Networks Integrated network, element, service and subscriber management IP/MPLS/ Optical Core 5 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Alcatel-Lucent Optics Division: More Value for Our Customers Alcatel-Lucent brings together the widest optical presence worldwide We can serve customers better everywhere Industry s strongest and most diversified customer base The partner of choice of converged global service providers the most comprehensive optical portfolio We can better help customers transform their networks for the future the best of innovation and research in optics We can deliver richer optical networking solutions Alcatel-Lucent in Optical Networking Global Expertise, Widespread Local Presence Alcatel-Lucent is a leader in every growing segment of the optical networking market # worldwide WDM - % OC % (source Dell Oro, Q06) 50,000 ADMs 8,000 MSPPs 4,00 WDM Systems,00 Cross-Connects 46,500 Km Submarine Networks Others 0% Alcatel-Lucent 5% Tellabs 7% Optical Networking Siemens 7% Nortel % Ericsson 5% NEC 6% # Source: Ovum-RHK Cisco 7% Fujitsu 0% Huawei 0% # worldwide Submarine MSPP - 8.5% (source Dell Oro, Q06) 90,000 ADMs 80,000 MSPPs 0,000 WDM Sys/Nodes 8,00 Cross-Connects Best technology Massive customer references Best market share More than 700 customers in 50 countries 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

4 Optics: Locations Greenwich Plano Murray Hill, Holmdel Shanghai Chengdu Transport Protocols in Public Networks Westford Paris, Calais Stuttgart, Nuremberg Vimercate, Trieste, Genoa 9 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Transport Networks (wire-line) Protocols for Transport Networks Transport networks are the means to transport end-user services Access networks: Transport from the end-user premises (CP = Customer Premises) to a "service node" Metro or Core networks: Transport between two "service nodes" Examples of service nodes Digital Switch for voice services IP router for IP services CP Access CPE Metro Core Service Nodes Public Network Metro Access CPE CP Various protocols are in use for transport of information over (wire-line) public networks DWDM (OTN) - Layer SDH / SONET - Layer ISDN - Layer Ethernet (CSMA/CD) - Layer and Layer ATM - Layer MPLS - Layer ~ IP - Layer Multiple protocols need to be "stacked" to get the desired capabilities IP -> ATM -> SDH IP -> Ethernet -> DWDM IP -> MPLS -> Ethernet -> MPLS -> SDH etc (any meaningful combination) Cours Réseaux Optiques Partie I March 008 Cours Réseaux Optiques Partie I March 008

5 Protocol Stacking Technical Factors distinguishing protocols () Voice Private Lines Data (IP, IP, MPLS, etc.) Ethernet*.86 RPR FR POS HDLC* ATM SONET/SDH WDM/OTN Fiber SANs ESCON* Fibre Channel* FICON* GFP Video DVI* (Under Study) Bandwidth Efficiency The ability to transport any traffic volume from the end-users and keep the public network well filled Statistical multiplexing gain is inherently present in datagram protocols High protocol stacks decrease efficiency (e.g. ATM "cell-tax") In case of congestion, delay sensitive traffic should be favored Scalability Scalability of speed: the bandwidth of links can be increased without adding hardware or by adding minimal hardware Scalability of size: network elements can be added to an existing network without loss of performance e.g. impact of network diameter on convergence time of routing protocols Delay, delay variation This is predominantly an issue for continuous bit-rate services (voice, video) TDM (SDH, ISDN) is optimized for these services Connection-oriented datagram protocols (ATM) are "good-enough" Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Technical Factors distinguishing protocols () Complexity Complexity covers the operational aspects of a network. The more effort is required to add/change network paths/parameters or to isolate faults, the costlier it is for a service provider The advantage of IP & Ethernet is that routing is taken care of automatically. However, this is not a principal difference. ASTN/GMPLS is a new development, which provides SDH with capabilities comparable to OSPF and IS-IS. Robustness The network must be fault-tolerant: failed nodes may not bring down a network; traffic is automatically rerouted after link or node failures There is some resilience against human error Security Keep traffic streams of different end-users separated. Much more difficult in case no dedicated "layer" is available for the service provider (e.g. IP) Prevent customers from using more bandwidth or higher priority than their contract allows Non-technical factors to favor protocols Cost (at the network level) The number one selection criteria Installed Base The installed base often limits the choices for a service provider when it comes to buying new equipment Changing means building a separate network (overlay), train the staff, maintain new sets of spares, solve inter-working issues with old network Management Systems The availability of a good network management system saves a lot of operational costs in the day-to-day running of the network: adding nodes, adding customers/bandwidth, troubleshooting, collecting network statistics Standards Compliance Necessary to get inter-working with other service providers Necessary for inter-working between equipment vendors; allows a service provider to buy systems from multiple vendors: keeps prices down 5 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

6 Difficulties in changing protocols Companies are often strongly bound to certain protocols. Only big companies can afford to support multiple protocols Cisco -- IP Lucent ONG -- DWDM, SDH Equipment Vendors Protocol choice is coupled to Technology Product Range is built around certain protocols Service Providers Installed Equipment base Existing Customer base In practice it is impossible for a company to change protocol quickly Adapt evolutionary (preferred, but takes time) Buy other company (costly, but quick) Multiplexing Technologies 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Multiplexing Techniques Multiplexing Techniques - TDM Multiplexing is a method to aggregate low speed traffic onto a high speed communication link. Multiplexing techniques: Frequency Domain Multiplexing (FDM) Each analog channel is modulated using a different carrier frequency Time Domain Multiplexing (TDM) Each digital channel is given its own time slot. Examples: PDH, SDH and SONET Wavelength Division Multiplexing (WDM) Each channel is given its own optical wavelength (color) Bits or bytes successively retrieved from the different channels to build a single bit stream Flexible traffic management; fixed bandwidth Mux/demux feature required PDH = Plesiochronous Digital Hierarchy, SDH= Synchronous Digital Hierarchy, SONET= Synchronous Optical Network) 9 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

7 Multiplexing Techniques - WDM Multiplexing Techniques - Capacities Gbit/s NxSTM64 NxSTM STM64 8 STM56 Data STM-N Merging of optical traffic on a single fiber Expansible bandwidth Cost reduction (reuse of existing optical signals) Independence of bit rates and frame formats DWDM = Dense WDM CWDM = Coarse WDM STM6 STM4 STM 0, 0, Cours Réseaux Optiques Partie I March 008 Cours Réseaux Optiques Partie I March 008 PCM (Pulse Code Modulation) Before SDH: PDH Voice codec according Shannon/Nyquist theorem: Phone analog signal band =.4 khz (rounded up to 4 khz) Required sampling rate : 8000Hz (i.e. sample every 5 µs) No gain above since higher harmonics are cut by the low-pass filter All Time Intervals in digital transport networks are multiple of 5 µs PCM (MIC (Modulation par Impulsion et Codage) is the basis of digital transmission in PSTN: Codec delivers data blocks of 8 bits 64 kbit/s per channel All timeslots in digital transport networks are multiple of 64 kbit/s Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

8 E Frame Structure (MIC G) Basic E frame at.048mbit/s (T at.544mbit/s in the US) contains 0 TS, framing byte (TS0), signaling channel (TS6) synchronously multiplexed TS0 Frame Alignment Voice sample 8bits TS Digital channel: 8 bits x 8000 Hz = 64 kbit/s x 8 = 56 bits (5 µs) 4 signaling bits per channel TS5 TS7 TS TS6 Out-of-band Signaling Need 5 frames for signaling of the 0 voice channels. These 5 frames + 6 th constitute a multiframe (G.704) PDH (Plesiochronous Digital Hierarchy) Old TDM technique (G.70) of E channels ( tributaries ) Multiplexing of 4 tributary channels into the next multiplex Nodes have their own clock; E channels are plesiochronous ( Hz ± 0 Hz) Rate adaptation during multiplexing steps: Addition of stuffing bits to each plesiochronous tributary to make them synchronous and in phase (process called positive justification ) Synchronization and signaling bits added (stuffing bits must be signaled for the remote end to eliminate them) Bitrate of Multiplex N+ > 4 x bitrate of Multiplex N No direct access to tributary signals, requirement for complete demultiplexing No (or little) standard for optical signals at PDH speeds Still used for the lower multiplexing stages 5 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 PDH Multiplexing PDH Transmission Rates Add and drop of low bit rates is very difficult as all channels must be demultiplexed and then multiplexed again Japan North America Europe & rest of the world J kbit/s kbit/s E5 40 Mbit/s J4 x kbit/s kbit/s DS4 x kbit/s E4 x G.75 x6 x4 G.755 x4 G.75 4 Mbit/s 4 Mbit/s J 064 kbit/s G.75 x5 x kbit/s G.75 DS 4 68 kbit/s x4 G.75 E Mbit/s 8 Mbit/s 8 Mbit/s Mbit/s DS, J DS, J 6 kbit/s x4 G kbit/s x G.747 x4 x kbit/s x4 G kbit/s E E xn: Multiplexing factor Interworking (G.80) DS0, E0, J0 64 kbit/s 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

9 SDH Historical Background SDH Overview & Advantages 984: Difficulties encountered with the interconnection of high-bitrate systems 985: Solution by Bellcore SONET Introduction of synchronous multiplexing bases Frame at Mbit/s adapted for T 986: Investigations on synchronous transmission within CCITT Objective: interface at about 50 Mbit/s 987: First CCITT Task force on the subject USA proposition based on SONET solution and taking into account of the European hierarchy 988: Definition of the SDH principles 989: Publication of first Recommendations - G.707, G.708, G which form the basis of SDH 9 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 SDH (Synchronous Digital Hierarchy) Derived from North American SONET standard in 988 State of the art synchronous TDM technology for backbone communication over optical fibers Synchronous means that multiplexing is synchronous, direct access/visibility to tributaries transmission is synchronous: reception clock is extracted incoming signal the whole network is synchronized to a single master clock which is distributed to all network elements In order for this clock not to become a single point of failure, most networks have several backup clocks International technology (except US with SONET) SDH is based on international standards from ITU-T (former CCITT) and ETSI Advantages of SDH () High transmission rates Payload > 50 Mbit/s for STM- Currently up to 40 Gbit/s, above DWDM is used Future proof platform (STM-56, STM-04) Optical fiber support High transmission quality Standardized physical interfaces with confined optical parameters Simplified add & drop function Direct access to tributary signal ( Mbit/s for example) in STM- aggregate signal Mixing of signals of different hierarchies/technologies in a single STM- Cours Réseaux Optiques Partie I March 008 Cours Réseaux Optiques Partie I March 008

10 Advantages of SDH () Flexibility Network able to transport different signals (Ethernet, Video, PAB, PDH, SDH, ATM, IP, etc) Guarantees services down to PDH High availability and reliability Provides various transmission protection schemes Highly reliable System Design with redundant hardware Built-in Operation, Administration, Maintenance and Provisioning (OAM&P) functions Associated with strong Network Management support International standardization in ITU-T Guarantee Multi-vendor Interoperability Compatibility of transmission equipments and networks worldwide Network Layering, Data Transparency Voice, Data, Video, Multimedia... IP Ethernet ATM SDH/SONET WDM Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Bit Ordering conventions Basic SDH Frame Structure and Transmission Principles The order of transmission of information in all the diagrams is first from left to right and then from top to bottom. Within each byte the most significant bit (MSB) is transmitted first. The most significant bit (bit ) is illustrated at the left in all the diagrams. MSB LSB Transmission order 5 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

11 Basic STM- Frame Structure (rectangular form) SDH Transmission Principle 9 columns (OH) 6 columns (payload) Frame period = 5 µs Row Row Row Row 4 Row 5 Row 6 Row 7 Row 8 Row 9 9 rows 5 RSOH AU Pointer MSOH SOH = Section OverHead Payload (VC-4) 50, 6 Mbit/s 70 bytes SDH is transmitted in frames. Each frame is exactly 5 µs in time. 5 ms The basic SDH frame is called STM- and is often represented as a block of 9 rows with 70 bytes STM- = RSOH = MSOH = AU = Synchronous Transport Module Level Regenerator Section Overhead Multiplex Section Overhead Administrative Unit payload payload payload payload payload payload payload payload payload RSOH Pointer (9 bytes) MSOH The transmission of STM-N frames is made serially row by row starting from the left with row column through column 70, then row column The frame rate is always frames per second, which is equivalent to a frame period/length of 5 µs 70 x 9 = 40 bytes per frame x 8 bits/byte = bits/frame bits/frame x frames/sec = Mbit/s = STM- t 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Scrambling STM-N Multiplexing/Interleaving Principle The STM-N (N=0,, 4, 6, 64, 56) signal must have sufficient bit timing content for clock recovery. A suitable bit pattern, which prevents a long sequence of ""s or "0"s is provided by scrambling the STM-N signal with a frame synchronous scrambler of sequence length 7 operating at the line rate and with generating polynomial = The scrambler runs continuously throughout the complete STM-N frame, except the first row of the STM-N (N = 64) SOH (9 N bytes, including the A and A framing bytes) which is not scrambled. STM- A STM- B STM- C STM- D 4 x STM- Bytes A B C D A B C D A STM-4 A higher order signal is created by byte interleaving the payload from the lower order signals. De-multiplexing is done in the opposite way. The bit rates of the higher order hierarchy levels are integer multiples of the STM- transmission rate. Frame rate of higher order hierarchy signals as well as lower order signals are the same: 8000 frames per second (5 µs) The overhead bytes are not carried forward. The multiplexer adds new overhead bytes in both directions 9 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

12 SONET and SDH Transmission Rates SONET signals Bit rates Equivalent SDH signals electrical optical Mbit/s electrical optical STS- OC- 5,84 STM-0 STM-0o STS- OC- 55,5 STM- STM-o STS-9 OC-9 466,56 STS- OC- 6,08 STM-4 STM-4o STS-8 OC-8 9, STS-6 OC-6 44,6 STS-48 OC , STM-6 STM-6o STS-9 OC-9 995,8 STM-64 STM-64o STS-768 OC , STM-56 STM-56o SDH Multiplexing Structure These hierarchy levels are not existing and are shown only for the sake of completeness 4 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Synchronous Multiplexing Definitions SOH Synchronous Transport Module STM-56 : 9,808 Gbit/s SOH STM-64 : 9,95 Gbit/s SOH STM-6 :,488 Gbit/s SOH STM-4 : 6 Mbit/s SOH STM- : 55 Mbit/s Tributary Unit or Administrative Unit -->TU= Tributary Unit -->AU = Administrative Unit Tributary Unit Group or Administrative Unit Group --> TUG : Tributary Unit Group -->AUG : Administrative Unit Group x56 x64 x6 x4 Administrative x AUG Unit Group AUG PTR POH x PTR POH AU4 Container Virtual Container Synchronous Transport Module Administrative Unit S O H Cn POH VCn POH VC-4 Tributary Tributary Virtual Container Unit Group Unit Container C4 (K) x PTR POH TUG x POH C VC- TU- x7 (L) PTR POH TUG POH C VC- x TU- (M) PTR POH POH C VC-=40 octets TU- POH C VC- Tributaries 964 kbit/s ATM 4476 kbit/s 468 kbit/s 6 kbit/s 048 kbit/s 544 kbit/s C-n (Container): Information structure which forms the network synchronous information payload for a virtual container. Size of C-n matches PDH, ATM, etc tributary bit-rates. VC-n (Virtual Container): LO VC consists of a single container i (i=,,,) and associated POH (Path OverHead). HO VC consists either of a single container i (i=4) or of an assembly of Tributary Unit Groups, together with Virtual Container POH appropriate to the level. TU-n (Tributary Unit): Consists of a VC-n and its associated pointer. TUG-n (Tributary Unit Group): not a physical entity, virtual structure grouping different sized TU to increase flexibility of the transport network. AU-n (Administrative Unit): Consists of an information payload (higher order virtual container) and associated pointer. AUG-n (Administrative Unit Group): Consists of a homogeneous group of AU-s or AU-4s. STM-N (Synchronous Transport Module): Contains N AUGs together with SOH. 4 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

13 4 M Kbit/s Kbit/s ATM 4476 Kbit/s 468 Kbit/s 6 Kbit/s 048 Kbit/s Synchronous Multiplexing Processes Synchronous Multiplexing TU-, klm numbering STM-64 x AU-4-6c VC-4-6c C4-64c STM-6 STM-4 STM- STM-0 x4 (adding SOH) x64 x6 x AUG x x x4 x4 x x AU-4-6c AU-4-4c AU-4 AU- Pointer processing VC-4-6c VC-4-4c VC-4 VC- Note : Concatenation (Rec. G707, G80) = A procedure whereby a multiplicity of Virtual Containers is associated one with another with the result that their combined capacity can be used as a single container across which bit sequence integrity is maintained. There is two types of concatenation : contiguous or virtual Multiplexing/Interleaving Aligning (adding pointer) Mapping + Justification + POH addition x7 x x TUG- TU - VC- x7 TUG- x x x4 TU - TU - TU - VC- VC- VC- contiguous concatenation C4-6c contiguous concatenation C4-4c C-4 C- C- C- C- KLM address of TU- defines its row in the VC4 : - K indicates TUG- rank used ( to ) - L indicates TUG- rank used ( to 7) - M indicates TU- rank used ( to ) TU N is marked with KLM address =. TU N is marked with KLM address = 4. TU N 6 is marked with KLM address = 7 STM- AUG AU 4 VC 4 TUG TUG TU K L M VC PI Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Multiplexing Structures Different Regional Options Steps of Multiplexing () 40Mbit/s VC-4 STM- STM-N AUG AU-4 VC-4 C Kbit/s AT STM- AUG AU-4 VC-4 C-4 European Structure of Multiplexing HIGHER ORDER MULTIPLEING AU- VC- TUG- 7 TUG- LOWER ORDER MULTIPLEING TU- VC- C- TU- VC- C- TU- VC- C Kbit/s 468 Kbit/s 6 Kbit/s 048 Kbit/s TU- VC- C- 544 Kbit/s SOH AU- 4 Pointer AU- VC- HIGHER ORDER MULTIPLEING TUG- TUG- TU- VC- C- TU- VC- C- LOWER ORDER TU- VC- C- MULTIPLEING TU- VC- C- 544 Kbit/s North America and Japan Structure of Multiplexing STM-N AUG AU-4 VC-4 C-4 TUG- TU- VC- AU- VC- C- 7 TUG- TU- VC- C- 964 Kbit/s AT M 4476 Kbit/s 468 Kbit/s 6 Kbit/s SOH P O H C-4 HIGHER ORDER MULTIPLEING LOWER ORDER MULTIPLEING TU- TU- VC- C- 048 Kbit/s VC- C- 544 VC Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

14 7 Asynchronous Mapping of 40 Mbit/s Signal into a VC-4 Steps of Multiplexing () 4/45Mbit/s VC- TU- VC-4 STM- Bytes One of nine rows in a VC-4 W 96 I 96 I Y 96 I Y 96 I Y 96 I STM- AUG AU-4 VC-4 C-4 TUG- TU- VC- 964 Kbit/s ATM AU- VC- C Kbit/s 468 Kbit/s 96 I Y 96 I Y 96 I Y 96 I 96 I Y 96 I Y 96 I Y 96 I 96 I Y 96 I SOH AU Pointer POINTER POH HIGHER ORDER MULTIPLEIN G TUG- LOWER ORDER MULTIPLEIN G TU- VC- C- TU- VC- C- TU- VC- 6 Kbit/s 048 Kbit/s C- 544 Kbit/s P Y 96 I Y 96 I 96 I Y 96 I Z 96 I SOH O H TU - C- VC- Y : RRRRRRRR : CRRRRROO : Path Overhead W Z : I I I I I I I I : I I I I I IS R I : Information Bit R: Fixed Stuff Bit O: Overhead Bit S: Justification Opportunity Bit C: Justification Control Bit VC-4 50 Cours Réseaux Optiques Partie I March 008 Asynchronous Mapping of a 45 Mbit/s Signal in a VC- Asynchronous Mapping of a 4 Mbit/s Signal in a VC- One of nine rows in a VC 84 Bytes 85 Bytes POH 8R 8R 00 I 8R 8 I 00 I 8R 8 I 00 I / P OH rows of R R C I I I I I C C R R O O R S C C R R R R R R I : R: O: S: C: Information Bit fixed Stuff Bit Overhead Bit stuff opportunity stuff control bit J B C C C fixed stuff information 8 fixed bits fixed stuff stuff fixed stuff fixed stuff information bits S S = stuff opportunities average (bits / STM frame) = 496 bits / STM frame = 468 kbit/s

15 pointer AU-4 TU- C PTR POH VC- Steps of Multiplexing () Mbit/s VC- TU- VC-4 STM- STM- AUG AU-4 VC-4 C Kbit/s ATM TUG- TU- VC- RSOH MSOH J STM- : 70 columns * 9 rows VC-4 : 6 columns * 9 rows 7 TUG- C- TU- VC- C Kbit/s 468 Kbit/s 6 Kbit/s SDH Pointer Function TU- VC- C- 048 Kbit/s TU- VC- C- 544 Kbit/s TUG- 86 columns TUG- columns Note : To decrease the relative size of the path overhead with regard to the payload, the C duration is 500us (and not 5us), it means four Mbits/s frames. The Mbits/s signal is then inserted in a C container of 9 bytes. 5 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 AU/TU-n Pointer Function AU/TU-n Pointer Position Determination (addressing): The pointer indicates where the VC-n path overhead begins in higher order frame Bit Rate Adaptation: The pointer provides a method of allowing flexible and dynamic alignment of the VC-n within the AU/TU-n frame: the VC-n is allowed to "float" within the AU/TU -n frame. Thus, the pointer is able to accommodate differences, not only in the phases between VC-n and the higher order frame, but also in the frame rates Pointer addressing only every bytes H H HHH O O O Y Y J SOH - AU pointer - TU pointer FRAME N Pointer SOH SOH J VC4 FRAME N Negative Justification ( Bytes) Positive Justification ( Bytes) FRAME N+ Pointer SOH FRAME N+ SOH SOH SOH Pointer SOH SOH SOH J SOH SOH SOH t 55 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

16 AU/TU-n Pointer Justification Positive Justification/Stuffing Pointer use is associated to a justification process PT PT empty Step : Pointer value n before stuffing J J FRAME N J J H Y Y H H HH n PT PT PT- J J J FRAME N+ FRAME N+ J PT+ J S J J H Y Y H empty H HH n Step : The pointer value is inverted in the I-bits. The three bytes following the H-bytes contain stuffing bits PT- 57 Cours Réseaux Optiques Partie I March 008 J Negative Justification: bit-rate of the container > bit-rate of the frame there are more data received than can be transmitted in the frame J FRAME N+ PT+ J J Positive Justification: bit-rate of the container < bit-rate of the frame there are less data received than can be transmitted in the frame empty H Y Y H H HH 58 Cours Réseaux Optiques Partie I March 008 n+ Step : The pointer has the pointer value n+ VC-4 is slowed down... J- Byte (. Byte of VC -4)... Stuff bytes (,, ) Negative Justification/Stuffing AU-n/TU- Pointer Coding H Y Y H empty H HH Step : Pointer value n before stuffing H H H N N N N S S I D I D I D I D I D Note : The TU pointer is elaborated by associating in the 500us period, 4 bytes named V, V, V, V4 H Y Y H data H HH empty H Y Y H H HH n- n n Step : Step : The pointer value is inverted in the D-bits. Missing payload bytes are transmitted using H bytes which contains valid information The pointer has the pointer value n- VC-4 is accelerated... J- Byte (. Byte of VC -4)... Stuff bytes (,, ) I D N Increment Decrement New data flag 0 bit pointer value Negative justification opportunity New Data Flag (bit -4 of H): Notification of a new pointer value Set/Enabled when at least out of 4 bits match "00 Reset/Disabled when at least out of 4 bits match "00 (normal operation) Invalid with other codes SS bits (bit 5-6 of H): Composition of the AU-n /TU-n frame (AU/TU type) Concatenation Indication 00SS (SS bits are unspecified) NOTE The pointer is set to all ""s when AIS occurs. T Positive justification opportunity Pointer value (bit 7-8 of H + bit -8 of H): Normal range is: for AMU-4, AU-: for TU-: Negative justification Invert 5 D-bits Accept majority vote V, V = pointer which position V5 V = positive/negative justification opportunity V4 = reserve Positive justification Invert 5 I-bits Accept majority vote 0-78 decimal decimal H: Pointer action byte (Used for information bytes in case of negative stuffing) 59 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

17 SDH Frame Structure - Overheads RSOH: Regenerator Section Overhead MSOH: Multiplex Section Overhead POH: Path Overhead Overheads RSOH 9 COLUMNS Virtual Container 4 60 COLUMNS J B C STM-N VC-4 Regenerators RSO H MSOH STM-N VC-4 AU Pointer G F VC-4 VC-i POH VC-4 VC-4 VC-i H4 MSOH F VC-i POH VC-i VC-i K G-70 G 70 Section Overhead bytes N Path overhead bytespayload data bytes These three path and line sections are associated with Equipment Layers Note: Bytes B, D-D, E, E, F, K and K are only defined for the first STM- 6 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Tasks of the SOH Overheads Bytes RSOH Quality Supervision Regenerator Section OverHead A A A A A A J0 B E F D D D NU NU NU NU AU Pointer H Y Y H * * H H H Maintenance Functions SOH Frame Alignment Multiplex Section OverHead B B B K K D4 D5 D6 D7 D8 D9 D0 D D S Z Z Z Z M E Voice Connection Data Channels Line Protection A-A: Frame Alignment pattern, A= 00 (F6) A= (8) - not scrambled The FAW word of an STM-N frame is composed of N A bytes followed by N A bytes (6xN bytes). J0: Regenerator section trace identifier, 6 bytes frame (First byte = CRC-7) B: Regenerator section error monitoring function, BIP-8 : Bit Interleaved Parity 8 code E: Orderwire channel for voice communication, accessed at regenerators F: User channel allocated for user specific purposes D-D-D: Data Communication Channel (DCCr = 9kbit/s) NU : Bytes reserved for national use : Bytes reserved for future international standardisation 6 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

18 Bit Interleaved Parity n (BIP-n) code Overhead Bytes MSOH Entire block for the BIP-n check all bits of STM-N frame for B { all bits minus RSOH for B n bit sequence n bit n bit.. n.. n.... n Regenerator Section OverHead AU Pointer Multiplex Section OverHead A A A A A A J0 NU NU B E F NU NU D D D H Y Y H * * H H H B B B K K D4 D5 D6 D7 D8 D9 D0 D D S Z Z Z Z M E NU NU Even Parity Check # Even Parity Check # P P P.. Pn n bit. Even Parity Check #n BIP-n codeword: computed over relevant part of frame of frame after scrambling and is placed in byte B/B of the frame + before scrambling B: Multiplex Section error monitoring function, BIP-N x 4 : Bit Interleaved Parity N x 4 K-K (b -b5): Automatic Protection Switching (APS) channel K (b6 -b8): MS-RDI (Multiplex Section Remote Defect Indication) or AIS Indication D4 to D: Data Communication Channel (DCCm = 576kbit/s) S (b5 -b8): Synchronization Status Messages (SSM), timing marker for clock traceability M: MS-REI, Multiplex Section Remote Error Indication detected by B Z-Z: Spare bytes, not yet defined E: Orderwire channel for voice communication between multiplexers NU : Bytes reserved for national use : Bytes reserved for future international standardisation 65 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Tasks of the POH Overhead Bytes VC-4/ POH Mapping Identification Maintenance Functions VC Quality Supervision POH Connectivity Check User Channel Alarm Information The POH provides for integrity of communication between the point of assembly of a Virtual Container (VC) and its point of disassembly. J B C G F H4 F K N J: Path Trace/Trail Trace Identifier (TTI): this byte is used to transmit repetitively a Path Access Point Identifier so that a path receiving terminal can verify its continued connection to the intended transmitter, 6 bytes string (first byte = CRC-7) B: Path error monitoring function for VC-4-c/VC-4/VC-, BIP-8 C: Trail Signal Label = Composition of the VC-4-c/VC-4/VC- (00 = Unequipped, 0= Equipped - non-specific, 0 = TUG structure, 04 = Async. mapping of 4 or 45 Mbits/s into the C-, = Async. mapping of 40 Mbits/s into the C-4, = ATM mapping, 6= PPP/HDLC, B = GFP, FF= VC-AIS) G: Remote path status (REI (bit -4), RDI (bit 5)) detected at remote end by B F/F: user data channel reserved for user communication purposes between path elements and payload dependent. H4: Position indicator (e.g. used as a multiframe position indicator for the TU-) K (b-b4): Automatic Protection Switching (APS) channel for VC Trail Protection at VC- 4/ path levels (not used today) N: Network operator byte, allocated for Tandem Connection Monitoring (TCM) 67 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

19 Overhead Bytes VC- POH V5: BIP REI RFI L L L RDI BIP- = VC- error monitoring REI = Remote Error Indication, detected by BIP- RFI = Remote Failure Indication > unequipped > equipped - non-specific > asynchronous L, L, L = VC- signal label 0 ---> bit synchronous > byte synchronous RDI = Remote Defect Indication: Alarms on the remote VC-, after protection J: VC- Path Trace / Trail Trace Identifier, same as J for the VC-4/ N: Network operator byte allocated to provide a Tandem Connection Monitoring (TCM) function K4: - bits - 4 : Automatic Protection Switching (APS) channel - bits 5-7 : Reserved for optional use - bit 8 : Spare for future use V5 J N K4 Synchronization 69 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Why Synchronization? Synchronization Rules in SDH Phase differences cause frame slips Frame slips cause data loss Two signals to be synchronous must have: The same frequency (bit rate) The same phase The variation in position of bits on the time axis (Phase) relative to the ideal position (UI) is called jitter Jitter & wander tolerance specified by ITU standards time time Mbit/s (VC-) not usable for synchronization (pointer jitter) Single master clock is used for synchronization (G.8) Primary Reference Clock (PRC) Global Positioning System (GPS) All transmission nodes have to be synchronized The synchronization network is a network that reliably distributes synchronization information from a common reference source (masterclock) to those network elements that need to be synchronized. The synchronization network uses the STM-N links of the SDH transport network as physical layer for inter-office distribution. Intra-office distribution is build up with dedicated cabling. MHz or dedicated Mbit/s 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

20 Synchronization Protection S byte (b5-b8), Synchronization Status Message Failures in the synchronization distribution network can be overcome By duplication of equipment and/or By duplication of routing in combination with some selection mechanism at the receiving end (SDH nodes have several timing references) Reference selection mechanisms can be: Manual restoration Automatic restoration based on Network Management Automatic restoration based on Priority assignments Automatic restoration based on the Synchronization Status Messages (SSM) algorithm (ITU-T G.78) using the S byte of the STM-N overhead S bits (b5-b8) 0000 (00) Quality unknown SDH synchronization Quality Level description 000 (0) Rec. G8, PRC Quality (Primary Reference Clock): 0 - Rec. G8 Transit SSU-T Quality 000 (04) (Synchronization Supply Unit Transit):,5x0-9 Rec. G8 Local SSU-L Quality 000 (08) (Synchronization Supply Unit Transit): x0-8 Rec. G8, Synchronous Equipment Timing Source 0 () SEC Quality (SDH Equipment Clock) (5) Do not use for synchronization, DUS (Don t Use) or DNU (Do Not Use) Increasing Clock quality 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 SDH Network Synchronization Example SDH Network Synchronization Example SSMs applied in SDH ring network: normal situation SSMs applied in SDH ring network: restoration in progress PRC DUS SEC F PRC PRC PRC SEC A DUS PRC PRC Synchronization Status Message Reference Priority SEC DUS SEC F PRC PRC DUS PRC SEC A DUS PRC PRC Synchronization Status Message Reference Priority SEC E Active synchronization Stand-by synchronization B SEC SEC E PRC Active synchronization Stand-by synchronization B SEC PRC DUS D SEC DUS PRC C SEC DUS PRC SEC DUS D SEC DUS SEC C SEC SEC PRC 75 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

21 SDH Network Synchronization Example SSMs applied in SDH ring network: restoration completed DUS PRC SEC F DUS PRC PRC SEC A DUS PRC PRC Synchronization Status Message Reference Priority Protection Mechanisms SEC E Active synchronization Stand-by synchronization B SEC DUS PRC D SEC PRC DUS C SEC PRC PRC 77 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Protection Mechanisms Terminology Network Configurations Network Protection Schemes: Sub-Network Connection Protection (a.k.a Path Protection) SNC/N SNC/I Trail Protection Multiplex Section Protection Multiplex Section Protection (MSP) Multiplex Section Shared Protection Ring (MS-SPRing) Dual Node Interworking (DNI) Equipment Protection: :N equipment protection for electrical tributaries Importance of Automatic Protection Switching SDH networks are high capacity systems STM-64 = 9,000 voice telephone calls! Failure requires instant restoration SDH has Automatic Protection Switching (APS) Perhaps the most critical aspect of the technology, what distinguishes it most from IP Linear networks use duplicate fiber(s) and sometimes duplicate piece of equipment for protection Ring/Mesh networks use diverse routing Golden rule: 50 ms restoration time 79 Cours Réseaux Optiques Partie I March 008

22 Terminology SDH Network Configurations Revertive After the failed state has stopped to exist all protection switches automatically revert back to their original nonfailed state Configurable Wait-to-Restore (WtR) Timer Non-Revertive After the failed state has stopped to exist all protection switches remain in their current position thus becoming the normal non-failed state Point-to-point Configuration Linear Configuration SDH Terminal Multiplexer SDH Terminal Multiplexer Repeaters SDH Terminal Multiplexer SDH Add/Drop Multiplexer SDH Terminal Multiplexer Shared Each protection channel can be shared by more than one working channel, e.g. :N. Otherwise + The shared protection channel may be used for Extra-Traffic, e.g. :N Ring configuration Ring implementation choices: -fiber or 4-fiber unidirectional or bidirectional line switched or path switched STM rate 8 Cours Réseaux Optiques Partie I March 008 Sub-Network Connection Protection (SNCP) (a.k.a. Path Protection ) Path-level protection: SNCP protects a portion of a path (Subnetwork Connection) for VC-, VC-, VC-4, VC-4-4/6/64c SNCP is based on transmitting the signals to be protected over both a working and a protection path through the network. The SNC endpoint selects the best signal out of the two SNCP can be configured in any mix of topologies (e.g. ring, mesh, unprotected, MSP and MS-SPRING) Switch Criteria: transmission failure or external request Always Unidirectional (No APS signaling possible) Either Revertive or Non-Revertive No Extra Traffic : permanently bridged Different types of SNCP : SNC-I (Inherent) SNC-N (Non intrusive) ITU-T Rec. G.84 SDH Network SNCP Inherently Monitored: SNC/I Head End Bridge Subnetwork Connection Server Layer SSF Tail End Switch Signals are not terminated in front of the switch No monitoring is done on the protected signal itself, only the Server Layer defects (SSF) generate switch: Switching criteria at TU or AU level (TU-LOP & TU-AIS)

23 SNCP Non Intrusively Monitored: SNC/N VC Trail Protection Subnetwork Connection Server Layer Trail Subnetwork Connection Server Layer SF,SD SSF Head End Bridge SF,SD Non-Intrusive Monitors Tail End Switch Head End Bridge Non-Intrusive Monitors Tail End Switch Signals are not terminated in front of the switch Non intrusively Monitored (SNC/N): Switching criteria at TU/AU level and at VC level (VC- UNEQ, VC- TIM, VC- SD non-intrusively monitored) Signals are terminated in front of the switch APS protocol necessary (K) in Bidirectional mode Not implemented today Multiplex Section Protection (MSP) ITU-T Rec. G.84 + Multiplex Section Protection (MSP) Protects whole frame except RSOH Point-to-point protection Need the duplication of the STM-N interface board and the transmission support Switch Mode: either Revertive or Non Revertive + MSP has no Extra Traffic: permanently bridged : also defined, allowing extra traffic but less common Communication/switching mode: unidirectional or bidirectional + protection protocol using K and K (b-b5) bytes of MSOH following ITU-T Rec. G.84 Switch criteria: transmission failures (Server layer defects: LOS, LOF, MS- AIS, MS DEG (B errors) or external requests RSOH HO PTR MSOH Also implemented on POS interfaces of routers (called APS) HO-VC Network Element A (W) (P) STM-N port W P STM-N port Worker channel Protection channel (Standby) Unidirectional Switching: Both directions are independent: switch is performed in the tail end (failure detecting end) only No APS protocol required (although reporting is possible) STM-N port W P STM-N port Network Element B Tail End Switch Head End Bridge Bidirectional Switching: Both directions switch simultaneously APS protocol using K/K byte (carried on the protection line) to signal switch coordination

24 Multiplex Section Shared Protection Ring (MS-SPRing) Principles: MS-SPRING works in ring-type network with maximum 6 nodes. Protection is implemented by utilizing redundant bandwidth (capacity) For STM-64 MS-SPRING, each bi-directional line carries working channels and protection channels of STM- equivalent capacity in each direction. For STM-6, the system utilizes 8 working and 8 protection channels in each direction. Traffic is rerouted around a faulty segment using the redundant protection channels in case of a line-card or fiber failure Always bidirectional, requires APS signaling (K,K) Always Revertive (Shared Protection!) Possibility of Extra Traffic: use of protection capacity Optimal bandwidth use for meshed traffic ITU-T Rec. G.84 MS-SPRing Basic configuration no failure B # # A Working (-8) Protection (9-6) # # Protected channels : STM6 --> AU4 to 8, STM64 --> AU4 to Protection channels : STM6 --> AU4 9 to 6, STM64 --> AU4 to 64 C D MS-SPRing Single failure MS-SPRing Single failure () A A #9 Protected traffic + APS signalling B # Working (-8) Protection (9-6) Switching nodes D B # Working (-8) Protection (9-6) D # #9 Bridge # Intermediate Nodes (APS + Protection Pass-Through) #9 Bridge Protected traffic + APS signalling # # C # # C

25 MS-SPRing Single failure () MS-SPRing Ring Segmentation Restored traffic + APS signalling # A Switch A Switch #9 #9 B # APS Working (-8) Protection (9-6) D B # Working (-8) Protection (9-6) D # Intermediate (APS + Protection Pass-Through) #9 Bridge # #9 Bridge # # C # # C MS-SPRing Ring Segmentation () MS-SPRing Squelching A Switch A Switch AIS #9 #9 B # Working (-8) Protection (9-6) D B # AIS AIS Working (-8) Protection (9-6) AIS D # Misconnections! #9 Bridge # #9 Bridge AIS # # C # # C

26 Dual Node Interworking (DNI) ITU-T Rec. G.84 DNI between two MS-SPRing rings The DNI protection scheme protects the interconnection between two subnetworks within which the traffic is already protected by another network protection like MS-SPRING or SNCP Different combination possible: DNI between MS-SPRing rings DNI between SNCP rings DNI between a MS-SPRing and a SNCP ring Connection between the two ring networks is made using or 4 nodes DNI offers Protection against node failures and failures in the interconnection between the rings Independence of protection actions in both rings Better reliability than end-to-end path protection, especially for very long paths Service Selector Drop & Continue Primary Node STM-6 or STM-64 MS -SPRING Secundary Node Active VC -4 Connection Stand-by VC -4 Connection STM-6 or STM-64 MS -SPRING 97 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 DNI Interconnect Failures DNI Node Failure Service Selector Service Selector Drop & Continue Drop & Continue Primary Node Primary Node STM-6 or STM-64 STM-6 or STM-64 STM-6 or STM-64 STM-6 or STM-64 MS -SPRING MS -SPRING MS -SPRING MS -SPRING Secundary Node Secundary Node Active VC -4 Connection Active VC -4 Connection Stand-by VC -4 Connection Stand-by VC -4 Connection 99 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

27 HO SNCP Connection LO Connection Group (DNI -W Connection) HO DROP Connection LO Connection Group (DNI -P Connection) DNI between a MS-SPRing and a LO-SNCP Ring Vc/ Termination VC4 Sub- Network A MS -SPRING Sub- Network B SNCP Sub- Network C MS -SPRING A MS -SPRING B C Classification of Optical Interfaces & Transmission wavelengths LO -SNCP D Vc/ 0 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Classification of Optical Interfaces Classification of Optical Interfaces - Legend ITU-T G.957: Application Source nominal wavelength (nm) Intra - Inter -office office Short -haul Long-haul Type of fibre Rec. G.65 Rec. G.65 Rec. G.65 Rec. G.65 Rec. G.65 Rec. G.654 Distance (km) a) STM level Rec. G.65 STM- I- S-. S-. L-. L-. L-. STM-4 I-4 S-4. S-4. L-4. L-4. L-4. STM-6 I-6 S-6. S -6. L-6. L-6. L-6. a) These are target distances to be used for classification and not for specification. The possibility of applying the set of optical parameters in this Recommendation to single-channel systems on G.655 fibre is not to be precluded by the designation of the fibre types in the application codes. ITU-T G.957 for STM-, 4, 6 systems ITU-T G.69 for STM-64, 56 or STM-6 with OA systems Letter: Intra-office (I), Short-Reach (S), Long-Reach (L) Very-Long-Reach (V) Ultra-Long-Reach (U) L-6. STM-n level (blank) or = nominal 0 nm wavelength sources on G.65 fibre; = nominal 550 nm wavelength sources on G.65 fibre for short-haul applications and either G.65 or G.654 fibre for long-haul applications; = nominal 550 nm wavelength sources on G.65 fibre. G.65 (SSMF) : Characteristics of a standard single-mode optical fiber cable G.65 (DSF) : Characteristics of a dispersion-shifted optical fiber cable G.654 (CSF) : Characteristics of a cut-off shifted optical fiber cable G.655 (NZDSF) : Characteristics of a non-zero dispersion shifted optical fiber cable 0 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

28 Transmission Ranges Loss ITU G.69 comb Functional Equipment Specification WDM : Supervisory channel 50 GHz 80 traffic channels Wavelength SDH : 0 nm 550 nm 05 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Functional Block Diagram Representation ITU-T G.78 () - PI, RS, MS layers Functional Block Diagram Representation ITU-T G.78 () - HO-VC, LO-VC layers 07 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

29 Old G.78 Functional Block Diagram Representation C4 LOI HOA TTF PPI LPA LPT LPC HPA HPT HPC MSA MSP MST RST SPI M L K J H G F E D C B A TU Protection Physical Cn VCn VCn & TUG VC4 VC4 AU 4 MSOH RSOH Physical Interface Creation Creation Cross - Creation Creation Croos - AUG Creation Creation Interface connect connect Creation PDH Synchronous Tributary Cn VCn VCn TUG VC4 VC4 AU4/AUG STM-n Frame Typical Network Element Types & Network Applications PPI: LPA: LPT: LPC: HPA: HPT: HPC: MSA: MSP: MST: RST: SPI: Plésiochronous Physical Interface Low order Path Adaptation Low order Path Terminaison Low order Path Connection High order Path Adaptation High order Path Terminaison High order Path Connection Multiplex Section Adaptation Multiplex Section Protection Multiplex Section Terminaition Regeneration Section Terminaition Synchronous Physical interface L.O.I: Lower Order Interface H.O.A:High Order Assembler T.T.F: Transport Terminal Function 09 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 SDH Network Element Types Add & Drop Multiplexer VC-i processing VC-4 processing A Regenerator has the same speed on both Regenerato input and output. It is used to retime rand amplify the line signal. A Terminal Multiplexer (TM) is used to connect lower Terminal speed PDH or synchronous signals to a high speed communication link. Cours Réseaux Optiques Partie I March 008 G. 70 STM-N STM-N G. 70 STM-N STM-N STM-N STM-N STM-N STM-M STM-N STM-M VC-i VC-4 Multiplexer Multiplexer Multiplexer An Add/Drop Multiplexer (ADM) is used to to add Add or drop & Drop PDH or SDH signals to a high speed communication Multiplexer link. Has always at least two high speed connections. A Digital Cross-Connect can do everything the other network elements can and has even greater flexibility. VC-i VC-i Type I., I. Type III. G. 70 G. 70 Type II STM-N VC-4 VC-4 STM-N M > N STM-N Type III. STM-M Type I Type II., II. STM-N frame Aggregate signals Notation: ADM N/M N: Line/Aggregate STM-level M: Tributary STM-level Cours Réseaux Optiques Partie I March 008 West n Tributary Signals East STM-N frame Aggregate signals

30 PB PB PB Typical SDH Network Designs Metropolitan Network Applications of SDH LAN Metro - Edge End Office E, E DS STM-/4 E/FE/GbE Point to point Bus structure / 8 / 4 / 40 Mbit/s STM- ATM (55 Mbit/s) switch / 8 / 4 / 40 Mbit/s / 8 / 4 / 40 Mbit/s Ring structure ATM STM- switch (55 Mbit/s) LAN Backbone/Core Metro -Core POP/CO L D/OC STM-6 GbE IP Svcs Switch L D/OC Ring or Mesh scalable from STM-6 to STM-56 L D/OC STM-6 GbE STM /0 GbE L D/OC HO-SNC/ MS-SPRing STM-64 Hub Office E/FE GbE Ethernet / MPLS switch L ADM 6/ DCS 4/4/ ADM 64 LO-SNCP Ring STM-6 End Office L ADM / L ADM 6/ L ADM 64/ STM-/4 LO-SNCP Ring L ADM / L ADM 6/ STM-6 LO-SNCP Ring L ADM 6/ E, E DS, DS STM-/4 E/FE/GbE STM- E/FE Metro -Access S(H)DSL L ADM / L ADM 6/ L ADM / E, E DS, DS STM- E/FE S(H)DSL E, E DS, DS / 8 / 4 / 40 Mbit/s DWDM DWDM Managed DWDM Passive DWDM Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 SDH Communication Layers Circuit Switch SDH Terminal Multiplexer Repeaters SDH Add/Drop Multiplexer Repeaters Circuit Switch SDH Terminal Multiplexer OAM&P Regenerator Sections Regenerator Sections Multiplex Section Multiplex Section Path SDH Layering: Path Layer Multiplex Layer Regenerator Layer Photonic Layer Construction of AU-n Construction of STM-n Management of STM-n Transmission Electro -Optical Conversion 5 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

31 Fault Management () Fault Management () HP- RDI G HP- REI G SDH multiplexer STM-N Alarm Scheme High order path Multiplex section Regenerator section LOS/ LOF MS -RDI K BIP Err. B MS -REI M SDH regenerator MS -AIS AIS AIS K MS -RDI MS -BIP B HP- RDI HP- BIP B SDH multiplexer SDH alarms Description OH Byte LOS Loss of signal NES Non expected signal AIS Alarm indication signal Regenerator Section OOF Out of frame A, A LOF Loss of frame A, A RS DEG RS Degraded Signal B RS TIM RS trace identifier mismatch J0 Multiplex Section MS -AIS Multiplex section AIS K MS -RDI MS remote defect i ndication K MS -REI MS remote error i ndication M MS -DEG MS Degraded Signal B Administrative Unit AU-LOP Loss of AU pointer H, H AU-AIS AU alarm indication signal AU incl. H, H AU-PJE AU pointer justification event H, H High order path VC-4 UNEQ HO path unequipped C VC-4 RDI HO path remote defect indication G VC-4 REI HO path remote error i ndication G VC -4 TIM HO path trace i dentifier mismatch J VC-4 PLM HO path payload label mismatch C VC-4 DEG HO path error monitoring B 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Fault Management () Performance Monitoring SDH alarms Description OH Byte Tributary unit TU-LOP Loss of TU pointer V, V TU-AIS TU alarm i ndication signal TU incl, V to V4 TU-LOM TU l oss of multiframe H4 Low order path VC-/ UNEQ LO path unequipped V5 / C VC-/ RDI LO path remote defect indication V5 / G VC -/ REI LO path r emote error indication V5 / G VC-/ TIM LO path trace identifier mismatch J / J VC -/ PLM LO path payload label mismatch V5 / C VC -/ DEG LO path Degraded Signal V5 / B Bit error monitoring Locally via BIP parity check on B, B, B, V5 Overhead bytes Far-End using REI Definitions according ITU-T Rec. G.86 : Errored Block (EB): A block in which one or more bits are in error. Errored Second (ES): A one-second period with one or more errored blocks or at least one defect. Severely Errored Second (SES): A one-second period which contains 0% errored blocks or at least one defect. SES is a subset of ES. Unavailable Second (UAS) : if more than 0 consecutives SES. Background Block Error (BBE): An errored block not occurring as part of an SES 9 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

32 Performance Monitoring - Examples VC-4 : VC-4 block = 879 bit/s VC-4 rate : 506 kbit/s (879 bits/5 µs) ---> 8000 blocks/s SES if > 0% false blocks ---> SES if more than 400 false blocks VC- : VC- block : 0 bits (40 bytes x 8 bits) VC- rate : 40 kbit/s (0 bits/5 µs/4) ---> 000 blocks/s SES if > 0% false blocks ---> SES if more than 600 false blocks Network Management Architecture Server PC, Workstation - ECC or DCC : Embedded Control Channel, Data Communication Channel = D-D (DCCr) or D4-D (DCCm) - GNE = Gateway Network Element TCP/IP Network SDH Network NE ECC ECC NE - Configuration Management - Fault management - Performance Management - Security Management GNE ECC ECC NE Cours Réseaux Optiques Partie I March 008 Cours Réseaux Optiques Partie I March 008 Network Management Architecture Service Management Service Subscription Network Management Service Impact ASTN / GMPLS Network Circuit Design Filtered Alarms Configuration Information Element Management NE Provisioning Commands Raw Alarms Configuration Data Local Management (craft terminal) Network Element SDH & DWDM Technologies Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

33 Market Drivers for Optical Mesh Networking ASTN/GMPLS: Distributed Control Plane Today the SONET/SDH and DWDM layers of the network are quasi-static, and connection management is prone to human operator via the management plane Introduction of a ASTN/GMPLS control plane allow: Reduced Network Costs (CapEx) - Equipment and Fiber Infrastructure: Controlled network resource sharing Improved Network Utilization in meshed networks Reduced Operation Costs (OpEx) - Maintenance & Network Design Flexibility: Less design effort, easy enhancement and local elimination of bottlenecks as needed Cheaper and more accurate inventory (via automatic self-awareness, topology discovery, verification of physical neighbor) and plug-and-use operations Automatic connection set-up: reduce the operational burden of manual circuit provisioning Enhanced Services: Support multiple Quality of Service (QoS) for differentiated services with multiple grade of protection/restoration Support opportunities for operators to develop sustainable revenues through new services opportunities such as Optical Virtual Private Networks (VPN) with dynamic bandwidth Automatic path setup via O-UNI: create end-to-end connections with only the start and endpoint specified by the User or external equipment (router) I can request connections and change QoS Optical Transport Plane I-NNI Signaling based on IETF CR-LDP O-UNI / E-NNI Distributed Intelligence: We can auto -discover topology and resource availability Via Link State Advertisements (LSA) based on OSPF ONNS I have a flexible software architecture that supports module replacements I-NNI Signaling Control Plane We can calculate best routes for connections and restoration I can manage revenue producing services, bridge connection domains, and optimize network performance Centralized Intelligence: Management Plane NMI O-UNI / E-NNI We can set-up, tear down, and restore connections 5 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 The Role of Standards Standardization Standardization is extremely important To ensure inter-operability To defend/promote certain protocols (and their underlying technologies) Once a standards battle is lost, investments may have become worthless Standards bodies become part of the "battleground" Only technical argumentation is accepted Different standards bodies have each there "jurisdiction" ITU-T (Int'l, UN mandate), T (USA): DWDM, SDH, ATM, Ethernet IEEE (US dominated): Ethernet IETF (US dominated): IP, MPLS This creates some competition between these standards bodies In addition numerous industry fora are rallied around certain protocols IP/MPLS (MFA) Forum, Metro Ethernet Forum, RPR Alliance, 0 GbE Alliance 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

34 Standard Bodies SDH Standardization Linkage between Recommendations International Europe USA Focus ITU-T Transport, Switching ETSI ISO/IEC Transmission Hierarchy G.707 (SDH Frame) G.80, G.8, G.8, G.8 (Synchronization) Performance G.8, G.86 (Errors) Telcordia Management ANSI Transport IEEE Ethernet G.78/78 (Multiplexer) G.957 (Line System) G.784 (Management) IETF IP EEC EMC, Envir. Equipment TMN (Management) 9 Cours Réseaux Optiques Partie I March 008 ITU-T Recommendations SDH technology ITU-T Recommendations Management of SDH - Architecture G.70: G.704: G.705: G.707: G.78: G.78: G.8: G.8: G.8: G.85: G.84: G.84: G.957: G.69: Physical/electrical characteristics of hierarchical digital interfaces Synchronous frame structures used at 544, 6, 048, 8488 and kbit/s hierarchical levels Characteristics of plesiochronous digital hierarchy (PDH) equipment functional blocks Network node interface for the synchronous digital hierarchy (SDH) Synchronization Layer Functions Characteristics of synchronous digital hierarchy (SDH) equipment functional blocks Timing requirements at the outputs of slave clocks suitable for plesiochronous operation of international digital links Timing characteristics of SDH equipment slave clocks (SEC) The control of jitter and wander within digital networks which are based on PDH The control of jitter and wander within digital networks which are based on SDH Types and characteristics of SDH network protection architecture Interworking of SDH network protection architectures Optical interfaces for equipments and systems relating to the synchronous digital hierarchy Optical Interfaces for SDH Systems with Optical Amplifiers, and STM-64/56 systems G.704/Y.0: Generic framing procedure (GFP) G.704/Y.05: Link capacity adjustment scheme (LCAS) for virtual concatenated signals G.784: Synchronous Digital Hierarchy (SDH) management G.80: Architecture of transport networks based on the synchronous digital hierarchy (SDH) G.807/Y.0: Requirements for automatic switched transport networks (ASTN) G.86: Error performance parameters and objectives for international constant bit rate digital paths at or above the primary rate G.77/Y.70: Architecture and Specification of Data Communication Network M.00: Performance limits for bringing-into-service and maintenance of international digital paths, sections and transmission systems M.0.: Performance limits for bringing-into-service and maintenance of international SDH paths and multiplex sections Q.8: Lower Layer Protocol Profiles For the Q Interface Q.8: Upper Layer Protocol Profiles For the Q Interface

35 ITU-T Recommendations Fibers G.650: G.65: G.65: G.654: G.655: G.664: G.9: systems Definition and test methods for the relevant parameters of single-mode fibers Characteristics of a single-mode optical fibre cable Characteristics of a dispersion-shifted single-mode optical fibre cable Characteristics of a cut-off shifted single-mode optical fibre cable Characteristics of a non-zero dispersion shifted single-mode optical fibre cable General automatic power shut-down procedures for optical transport systems Parameters and calculation methodologies for reliability and availability of fiberoptic Conclusion and Future of SDH 4 Cours Réseaux Optiques Partie I March 008 Conclusion Multiple Benefits of SDH The Evolution of SDH High-capacity, granular bandwidth Powerful bandwidth management capabilities Interoperability between different vendor equipments International standard Compatible with PDH Network Multi-service transport (protocol opaque) Network able to carry different services (ATM, Ethernet, IP, SAN, etc) Robustness: Carrier-class design, high availability components APS supports millisecond fault tolerance Sophisticated OAM&P and network management capabilities Without theoretical limitation for high bit rates Limitation by electronics and PMD to STM-56 (40G) today Not enough bandwidth: optical backbones need multi-tbit/s DWDM. Perceived as legacy technology Investments shift away to Ethernet/IP technology but the latter are not transport oriented Transport Architecture Network Operating Model Interface Services CCITT First Generation SDH: Point-to-point optical line systems Basic path protection over mesh Fixed mapping Static circuit, manual provisioning 4/ or 4/4 cross-connection in DC and later ADM PDH (TDM PL) SDH or SONET only 994 ITU -T, ETSI, ANSI Standardization G.707,78,80 Managed transport focus Mux mountains Physically Large, multiple circuit Misc. packs for central functions Second Generation SDH: Ring subnetworks SNCP, MS-SPRing and DNI protection Flexible connectivity Automated provisioning 4/4// cross-connection in muxes PDH + packet (ATM, POS) SDH and SONET with SDH SONET conversion Network Synchronisation (G.8,8) Protection (G.84,84) STM-64 line interfaces, colored optics Some consolidation of central functions 6 Cours Réseaux Optiques Partie I March 008

36 Characteristics of Third Generation SDH ( MSPP ) Miniaturisation and consolidation Dynamic networking, On-demand Narrowband and broadband grooming resources, efficiency, granularity and aggregation in single platform trio GFP, VCAT, LCAS E to STM-64 in one platform Multiple protocol support Focus on Metro (= regional in Europe) PDH, SDH Flexibility legacy packet (ATM, POS) Optimised for STM-6 or STM-64 function Ethernet w/ L support, SAN E through to STM-6 interfaces Cost savings High capacity, non-blocking 4/4// local cross connect Simple engineering rules: any card, any slot Circuit packs used in several NE type Multi-layer mesh network architecture (G.807 ASTN) Capex Price reduction of optics Installation requirements Opex Power savings Floorspace Inherent reliability Native Ethernet 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Why so much fuss about Ethernet? Ethernet is one of the Hot Topics in the market today: Cheap and ubiquitous technology End customers are familiar with it, and perceive Ethernet Services as the solution to get a better bandwidth / price ratio since no protocol conversion Service Providers like its flexibility In scaling bandwidth of services easier than with existing data services (ATM, FR, TDM) or Topology, service connectivity Service Providers look at Ethernet as an enabler for Data transport in the network Industry is developing new technologies to improve Ethernet for Service Providers environments Native Ethernet in the Metro Based on carrier-class Ethernet Switches (L/)* performing Ethernet bridging, inter-connected using dark fibre or even WDM Protection via STP or LAG or proprietary schemes Security and service isolation with VLANs Security (IEEE 80.x, L ACL) Vendor proprietary L enhancements Administration via SNMP Topologies: PP, Hub & Spoke, Dual Homing Inefficient support of rings in terms of protection, bandwidth usage and fairness: this translates in higher fibre usage (Dual Homing architectures) Advantages: Cheap (very good price/gbe port or per bit ratio), robust Great scalability in bandwidth High port density: GbE, 0GbE Huge Switching capacity * Assuming non-mpls Feature richness ( IP-aware, enhanced statistics, etc) 9 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

37 Scalability Limits of Ethernet switching in the Public Network Scalability MAC Address Learning in Core (MAC Address Table explosion) Problems only in large, flat L networks. Mitigated by splitting MAC -domains by e.g. using a router (will be used by large corporate accounts anyway) Broadcast flooding VLAN label space limited to 4k Upper limit on Network Diameter due to Spanning Tree (IEEE: 7) Lack of Fairness Partially solved by policing and shaping, issue remains for best effort traffic Protection and Spanning Tree Layer protection relies on IEEE 80.D STP with typically ~0 s convergence time Now improved to less than s (with PHY fault monitors) with IEEE Std. 80.w-00 RSTP, but still not 50ms Bandwidth efficiency can be less than optimum with STP (unless MSTP) Assessment of the Optical (plain) Ethernet approach Seems the more straightforward way to introduce Ethernet in SP network and corresponds to what was deployed during the Hype years Drawbacks: Despite several innovative enhancements (IEEE, IETF or proprietary), still not considered carrier-grade solution Limited fast protection mechanisms (> 50 ms) Lack of fault isolation and poor OAM for network-level service management Impossibility to address cost-effectively Private Services (only EoSDH can dedicate L resources) Bad QoS perception, DiffServ QoS complex to engineer Not multi-service (TDM services require CEM), need overlay networks Economic Studies available to show that Ethernet over SDH is more competitive for Ethernet + TDM scenario Maximum link distances are shorter than 70km (w/ 000BASE-Z) Difficulty to link MANs with end-end redundancy and protection Ethernet scalability limits are applicable for the whole network 4 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Ethernet over SDH Next-Generation SDH: Ethernet over SDH One way to promote a protocol is to enhance it Make it cover more applications, especially those covered by competing protocols "Ethernet in the Metro" "Voice over IP" Enhance the economic life-time of SDH based on the following ideas Service Providers use largely SDH networks End-users use largely Ethernet Ethernet interfaces are very cheap Ethernet is relatively simple Mapping Ethernet in SDH as payload Bandwidth adaptation is needed to gain efficiency Ethernet -- variable with upper-bounds at 0, 00 and 000 Mbit/s SDH -- fixed at, 45, 50, 600, 400 and 9600 Mbit/s 4 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

38 Encapsulation Encapsulation with GFP (Generic Framing Procedure) acc. ITU-T G.704: Adaptation to synchronous transport layer Add GFP-header (8 bytes) to each Ethernet frame to indicate frame length and payload type, used for delineation Fill idle time with GFP idle-frames (4 bytes) Virtual Concatenation () To overcome the fixed payload sizes of SDH an inverse multiplexing scheme known as "virtual concatenation" is defined Possibility to make connections of which the bandwidth can be incremented in steps of a single VC-, VC- or VC-4 VC--v: = - 6 (one VC- Mbit/s) VC--v: = - 55 (one VC- 50 Mbit/s) VC-4-v: = - 55 (one VC-4 50 Mbit/s) GFP Header indicates payload length and type IDLE L / T Ethernet frame IDLE IDLE L / T Ethernet frame L / T Ethernet frame IDLE IDLE SDH Network 45 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Virtual Concatenation () Ethernet Bridging in SDH The implementation of virtual concatenation only affects the source and sink nodes. All intermediate SDH network elements remain unaware of virtual concatenation For this reason virtual concatenation is easier to introduce in existing SDH networks The differential network delay of the VC's is compensated in the sink node No routing constraints for the VC's in the concatenated group Inherent protection against failure If a VC in the concatenated group fails the rest of the group continues operating, but at less capacity - "load-sharing" Possibility to increase and decrease the end-to-end channel capacity "in-service". No bit errors in the transported payload LCAS (Link Capacity Adjustment Scheme) Protocol, ITU-T G.704 To gain more efficiency, the statistical properties of Ethernet traffic can be used by including a IEEE 80.D bridge function in an SDH box Traffic of multiple end-users can be combined Since traffic peaks are unlikely to coincide a certain over-subscription of the bandwidth is possible Use VLAN tags to distinguish frames from different end-users; the tags are removed when the traffic is returning In addition the bridge function can be used to support MAC Address learning, which makes multi-point connections possible Spanning Tree Protocol is used to keep the network "loop-free" and to provide restoration in case of link or node failures 47 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

39 Ethernet interface on SDH box Ethernet Multi-point Transport LAN port CP C P E S D H Public Network S D H Ethernet over SDH C P E CP Ethernet CP LAN WAN C P E S D H Public Network S D H C P E CP FE GbE PHY Ethernet Bridge GFP Encapsulation Virt. Concat. VC CP C P E S D H S D H C P E CP 49 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Ethernet Frame Ethernet Protocols PHY dependent Preamble 7 SFD Destination Address Source Address SFD = Start of Frame Delimiter FCS = Frame Check Sequence MAC frame (64-5) VLAN-tag (optional) Length/Type Data FCS Automatic Address learning (IEEE 80.D) Forward traffic to a certain port, based on destination address Fill MAC address table automatically, based on source addresses of incoming frames Age out learned addresses after 5 minutes, but timer is reset each time a learned address is confirmed by another frame Unknown addresses and Broadcast traffic is "flooded" (forwarded on all ports) Spanning Tree Protocol (STP) (IEEE 80.D) Remove loops in WAN network by blocking some links Special BPDUs (Bridge PDUs) are transmitted by bridges One bridge is declared the "root" Other bridges determine which port offers "least cost path" to root, based on bandwidth 5 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

40 Automatic Address Learning Spanning Tree Protocol A D A B MAC A MAC A MAC A C B All Initial Lowest Spanning bridges Situation BPDU Tree assume "wins" formed they're the root Bridge #5 0 0 Bridge # Bridge # Bridge # Bridge # Link Cost 000 / Capacity [Mbit/s] BPDU: Root ID Cost Own ID 5 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Ethernet Shared Transport Ethernet Trunking LAN WAN LAN Network CPE SDH Single VCn-v pipe, multiple customers LAN WAN Router PoP Internet SDH Trunking LAN interface CP CPE SDH Public Network SDH CPE CP SDH CPE CP CP SDH CPE CP SDH CPE Public Network SDH CPE CP SDH CPE CP 55 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

41 Packet Processing capabilities in SDH MSPP Overview of Carrier Ethernet Technologies Recent Developments Source: RHK Inc. MS-ADM= Multi-service ADM; MSTN= Multi-service Transport Node; ETP=Ethernet Transport Device; CE = Circuit emulation No packet features Packet-aware L features Pure packet 57 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Broadband Access (Residential + Business) Network Architecture Carrier Ethernet Technology Landscape Residential Data Voice Video Wireless Business Access ATM DSLAM FTTx DSL IP-DSLAM G/G Mobile, WiMA STM/OC GE N x GE FE E/DS FE/GE E/DS STM/OC/λ 59 Cours Réseaux Optiques Partie I March 008 Scalable Circuit & Packet Transport Ethernet/SDH/ WDM Aggregation Metro Transport Ethernet/ MPLS/VPLS 0GE 0GE Ethernet/SDH/ WDM (ROADM) Some form of enhanced Ethernet? Edge/Core G Core NetworGGSN Service k Router IP/MPLS SGSN Core Transport IP/MPLS Service Delivery Platforms Video Servers Headend PSTN Softswitch Voice Gateway High Speed Internet VoD IPTV VoIP Metro Ethernet encompasses all public Ethernet networking methods: Native Ethernet Switching IEEE 80.Q IEEE 80.ad PB IEEE 80.ah PBB PBT (PBB-TE) IEEE 80.7 RPR MPLS L VPN: VPWS, VPLS, H-VPLS (using carrier IP/MPLS backbone) T-MPLS Each Ethernet multiplexing layer option can run over any physical layers: SDH/SONET/OTN with GFP/VCAT/LCAS Optical Transport CWDM/DWDM Optical Transport IEEE 80. Ethernet PHY directly over fiber IEEE 80.ah EFM (Ethernet/xDSL, E-PON) MPLS ATM The MEF has carefully Competing defined and Carrier complementary Ethernet in at terms the same of services timeattributes and functions, not technology 60 Cours Réseaux Optiques Partie I March 008

42 Limitations of today s Ethernet solutions Mature and widely deployed technology but Service Provider devices switch based on customer addresses (C-MAC) C-MAC address table scalability Vulnerable to Denial of Service attacks Limited network scalability VID space STP bridge diameter Very limited Traffic Engineering capabilities Inefficient usage of network resources because of Spanning Tree requirement Slow Protection switching Inherently slow because STP is a distance-vector protocol Weak security because of self-learning network And (but not inherently linked with the technology itself) Limited OA&M (being worked in IEEE/ITU -T/MEF) Limited control plane tools Limited OSS tools (being worked by ITU -T/TMF/MEF) Evolution Objectives Change as little to existing data plane technology as possible Maintain low prices Backward compatibility with existing bridges Increase or Improve: Scalability Network utilization QoS Enable traffic engineering Fast protection switching Security Support a wide variety of services efficiently 6 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Ethernet Evolutions: IEEE 80.ad Provider Bridges (PB) Previously known as Q-in-Q, Now Approved Standard Enables segregation of customers and transparency for customer traffic Specifies dual VLAN stacking C-VLAN: Customer VLAN, S-VLAN: Provider VLAN: same tag format, but different Ethertype in TPID field, supports encoding of Drop Eligibility in DEI bit) Most common customer interface Unique Service ID per Service (S-VID) 4K Services (-bits) Forwarding is basic L with flooding/learning based on MAC DA/SA at the S-VID level and xstp for loop prevention Scalability Limited to 4K instances Still relies on (M)STP Ethernet Evolutions: IEEE 80.ah Provider Backbone Bridges (PBB) MAC-in-MAC encapsulation Virtualization: Isolates customer network from service provider network Hierarchical scaling 4K Interconnect Flood Domains Unique Service ID per Service using the I-Tag (I-SID) Forwarding is basic L with flooding/learning based on MAC DA/SA at the B-VID level and xstp for loop prevention Still uses (M)STP and does not address all scalability issues of Ethernet Scalability Massive service scale (4-bit) No need to burn an I-SID at every node for every service to build a PP mesh C-MACs learned and associated per B- VID/I-SID 6 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

43 Ethernet Evolutions: IEEE 80.Qay Provider Backbone Transport (PBT) or PBB-TE Ethernet Encapsulations PBT defines pp Ethernet transport tunnels Combines PBB with provisioned forwarding tables Turning off flooding, broadcasting, learning, Spanning Tree Protocol Instead, end-to-end paths are explicitly configured 60-bit label <B-DA + B-VID> used as a global connection identifier New VID semantic: VLANs are not used to limit broadcast domains. B-VIDs are used a path selector to B-DA, to establish two paths to destination DMAC A No translation/swapping IVL forwarding mode B-SA used to track source node Resiliency Primary and backup tunnels monitored by IEEE 80.ag CFM Unique Service ID per Service (I-SID) Scalability Tunnel scale (58-bit space) Service scale (4-bit space) I-SID per PP service IEEE 80. Basic Ethernet Frame IEEE 80.Q VLAN Frame IEEE 80.ad Provider Bridge Frame IEEE 80.ah Provider Backbone Bridge Frame MPLS Frame 65 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Ethernet Evolutions: IEEE 80.7 Resilient Packet Rings (RPR) Ethernet Evolutions: IEEE 80.7 Resilient Packet Rings (RPR) RPR is a packet-based transport technology RPR is a new MAC, different from the standard Ethernet MAC (IEEE 80. CSMA/CD) leveraging Resiliency of fibre rings Bandwidth efficiency of packet-switching technologies RPR applies strictly to Layer (logical) ring topologies Compare with Token Ring (IEEE 80.5) or FDDI, but bi-directional It does not need to be a physical ring, e.g. when RPR is transported over SDH, it is possible to have a logical ring over a physical network consisting of a mesh or multiple rings, but requires constant bandwidth over whole ring perimeter Spatial Reuse*: bandwidth efficiency by using destination stripping and routing via shortest leg of ring from source to destination Shared bandwidth, ring-level aggregation Supports a fairness protocol at node level 67 Cours Réseaux Optiques Partie I March 008 *: in theory, does not apply for bridged Ethernet services Fast restoration (50 ms) by using either traffic Wrapping (compare with MS-SPRing/BLSR) Steering Transport flexibility: RPR is Layer protocol and independent of Layer and Supports multiple QoS classes Plug&Play node hot-insertion, >00 per ring (large ring diameter but limited by latency) topology discovery/awareness, no master/slave node minimum provisioning/engineering Not very successful Requires special (costly) hardware Only useful in specific topologies E.g. limited ability to interconnect rings Benefits are local and don t extend network-wide Limited interworking with native Ethernet and Provider bridges Amendment to avoid flooding of L bridged traffic RPR has some application space but will remain isolated to certain metro regions 68 Cours Réseaux Optiques Partie I March 008

44 MPLS Evolutions: VPWS - Basic Concepts PWE (PseudoWire Emulation End to End) Virtual Private Wire Services Martini A PW is an Virtual Connection that emulates a physical link (such as an Ethernet, ATM, Frame Relay) The payload of packets traveling over a pseudowire are L frames (Ethernet, ATM, FR) rather than IP datagrams (L frames) Similar to ATM / FR services, uses tunnels and connections Carrier equipment does not peer with customer equipment Increases scalability and security Provides true multi-protocol support through transparency Upper Layer Protocol agnostic Most applications may be IP but many customers want FR/ATM like services from their provider rather than IP-based services Martini (PW) Circuits VPN A MPLS VPN Tunneling Protocols LDP SP Tunnels VPN Tunnels (inside SP Tunnels) VPN A VPN B CE Layer link PE VPN B CE P P PE CE VPN B Header Header L Data Packet Header Header L Data Packet PE CE VPN A 69 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 MPLS Evolutions: VPLS- Adds L Bridging Functions to PWE Provides Ethernet Private LAN (E-LAN) Builds on PWE signaling Adds switching intelligence to PE nodes Full mesh of VC LSPs and Tunnels No forwarding between MPLS tunnels and VC LSP Bundled Martini pseudo wires Requires a full mesh of VC LSPs VPLS Forwarding Learns MAC addresses per pseudo-wire (VC LSP) Forwarding based on MAC addresses Replicates multicast & broadcast frames Floods unknown frames Split-horizon for loop prevention drives full mesh requirement Standard IEEE 80.D code Used to interface with customer facing ports Provides local switching VPLS Reference Model VPN-A VPN-B Attachment circuit CE CE VC PE B VPLS (bridge) instance Tunnel LSP B P VPLS-A PE CE PE MTU-s CE MTU-s VPN-A L aggregation Ethernet Network CE CE VPN-B VPN-B Defines an Ethernet (IEEE 80.D) learning bridge model over carrier IP/MPLS Full mesh of Tunnel LSPs is established between VPLS-aware PEs (via RSVP-TE) Layer- VC LSPs are set up in Tunnel LSPs (via e.g. LDP) PEs do MAC learning/bridging on a per LSP basis and map C-VLANs into VC LSP Emulates a single distributed IEEE 80.Q switch VPLS topology can be point-to-multipoint, any-to-any (full / partial mesh) Benefit from all other MPLS advantages: Traffic Engineering, Fast Re-Route, QoS B 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

45 VPLS Scalability: H-VPLS VPLS VPLS HVPLS Tunnels tied to physical infrastructure Dedicated PP pseudowire mesh with split-horizon forwarding within the core between PEs for every service instance Inter -domain VPLS Scalability PW sessions signaled via MPLS control plane Tunnels scale as PEs are added At a minimum for n PEs there are n tunnels (0 bits) Pseudowires scale n!/(n-)! * service count (0 bits) 7 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 H-VPLS MPLS Evolutions: T-MPLS Introduced to offload PW mesh scaling issues as service count grows MTU-s introduction requires fewer PEs and smaller PW mesh Implementations often seek to increase service count, which in turn drives larger MAC table size requirements Scalability PW sessions signaled via MPLS control plane Hub and spoke PW architecture reduces PW mesh issue As service count grows, trade off MAC table size vs. PW mesh T-MPLS = "Transport MPLS Attempt by ITU (SG&SG5) to formalize a profile of MPLS for L transport network applications Functional modeling, strict decoupling fwd/ctl/mgmt, compliance with ITU -T's transport network principles Defined as: A co-ps transport network technology Reusing MPLS principles and fwd-plane design MPLS PDU format, MPLS processes (TTL, ) With some options fixed to suit ITU-style transport: No PHP, ECMP No uniform model Strictly connection-oriented ( -> no merging) Strong Transport OAM based on G.84 (vs. IETF LSP Ping) Strong Resilience mechanisms based on G.8/G.8 (vs. IETF FRR) Currently no defined control nor management plane Plan to use GMPLS/ASTN control plane 75 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

46 Main Ethernet Standardization Organizations Metro Ethernet Forum ITU-T Primary SDO where most large carriers and equipment vendors participate and where the expertise in transport networks resides. Ethernet over Transport architecture and equipment standardization is in SG5, other functions such as OA&M are in SG. IEEE 80 Primary organization historically responsible for Ethernet specification. Recently engaged in specifications to carry Ethernet over carrier transport networks, including hierarchical forwarding and OA&M. Carrier Ethernet Carrier Ethernet is a ubiquitous, standardized, carrier-class SERVICE defined by five attributes that distinguish Carrier Ethernet from familiar LAN based Ethernet It brings the compelling business benefit of the Ethernet cost model to achieve significant savings Metro Ethernet Forum Primary organization responsible for definition of Ethernet services, User- Network/Network-Network Interfaces and Implementation Agreements to foment the quick adoption of Ethernet transport services (Technical + Marketing committees). IETF Primary organization responsible for definition of Virtual Private LAN Service (VPLS) in the LVPN WG (Internet area), Ethernet tunneling on IP/MPLS network with pseudowires (VPWS) in the pwe WG (Transport area), and MPLS. Carrier Ethernet Attributes Standardized Services Scalability Service Management Reliability Quality of Service 77 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 MEF Certified Companies January 007 TM SERVICE PROVIDERS Transport network evolution EQUIPMENT MANUFACTURERS 79 Cours Réseaux Optiques Partie I March 008 Contents Carrier All Ethernet Rights Reserved Technical Alcatel-Lucent Future 006, Work ##### Marketing Certification Membership 80 Cours Réseaux Optiques Partie I March 008

47 Application drivers: Service Transformation Triple Play VoIP, HSI and IPTV (unicast & multicast) Mobile Multimedia services, visiophony, video streaming Ethernet Services Managed Ethernet Services including Virtual leased line (E-Line) and Virtual private LAN service (E-LAN), IP-VPN SAN interconnect Business continuity, disaster recovery Video transport Production and contribution networks New residential and business services drive the transport network transformation Application drivers: Impact for the Network 4% Bandwidth Factor 6 traffic increase Between 004 and 008 7% % 6% 0% 004 Source: Alcatel Study % 6x % % Diversity An unpredictable mix of technologies and protocols % 008 5% 7% 4% Growth in metro and core, but with important service diversity Private Lines (Enterprise DIA, Retail, Wholesale) Voice (Fixed + Mobile) Video Distribution Broadband Internet Access, Residential Data Services (ATM/FR, L-VPN, L-VPN) Broadband Internet Access, SMEs 8 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Transport Network Definition and Requirements Transport Network Meeting Operator Rationales: focus on scalability and operational simplification Map & Switch Map at Edge Lot of sub.5g TDM clients are there and grow due to mobile More efficient transport for L and L services Map at Edge Scalability Ability to support any number of client traffic instances whatever network size, from access to core Reliable aggregation and transport of any client traffic type, in any scale, at the lowest cost per bit Multi-service Ability to deliver any type of client traffic (transparency to service) Quality Ability to ensure that client traffic is reliably delivered at monitored performance ee Cost-Efficiency Acting as server layer for all the rest by keeping processing complexity low and operations easy Client L L0 Squeeze (stack) ATM, FR, Ethernet SONET/SDH WDM SAN, PDH, IP/MPLS Grow (BW) Packet Networking L L0 SAN, PDH, ATM, FR, Ethernet, IP/MPLS, Clear Channel SONET/ SDH T-MPLS Packet Photonic Switching ODU Clear channel Aggregation for Carriers Carrier and large enterprise Core Multi-vendor capable lambda networks Distributed regeneration and recoloring Transport values have evolved through long TDM evolution They hold through transition to packets To increase scalability, bring networking into layer-0 and packet into layer- Layer-: universal matrix and transport-optimized MPLS Layer-0: Range from ROADM to tunable multi-degree switching 8 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

48 Technology Enabler: Universal Switch matrix for smooth transition from TDM to packet Technology Enabler: Transport MPLS (T-MPLS) Today / 00% Circuit Current practice - MSPP migration Start with SDH only, introduce packets gradually Universal Switch Universal Switch New practice - Transport Switch Vision / 00% Packet Start with packets only, introduce SDH gradually Universal Switch BUT transport unfriendly Linked to IP Allows connection-less networking OAM below transport standards No separation of data & ctrl plane MPLS Carrier-grade packet networking Strong market adoption Purpose-designed for packet transport Client-Server independence Strictly connection-oriented Transport-grade OAM & survivability NMS or GMPLS control plane STM- E Photonic card STM-64 STM-64 0GE GE FE 0GE TDM card Packet card T-MPLS New ITU-T standard Profile of MPLS improved and cost optimized Deploy SDH networks with full scalability to packet transport Deploy packet-centric network with true TDM capability T-MPLS = MPLS IP + OAM (+ GMPLS in option) 85 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 T-MPLS becomes MPLS-TP with IETF/ITU-T Joint Working Team IETF and ITU-T formed a Joint Working Team to find a way to bring the two technologies together Undertook a technical feasibility study, and identified NO show-stoppers MPLS Transport Profile (MPLS-TP) definition FTTx Integration of MPLS-TP into transport network Alignment of current T-MPLS Recommendations with MPLS-TP Convergent solution termed MPLS Transport Profile (MPLS-TP) 87 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

49 FTTP Market & Drivers Broadband Access Market - Current Status Broadband access market is mature now: Broadband access penetration in Europe 0% today, 40% by 008 Full-blown (bandwidth) competition: DSL, Cable Line prices have dropped (far) below $40 Average Revenue per User (ARPU) is also decreasing Limitations in bandwidth and coverage Careful introduction of: New value-added services & bundles (triple play) Internet Services (Peer to peer, gaming, hosting) TV Entertainment Services (Video broadcast, VoD, PVR (SDTV), HDTV) Conversational Services (VoIP, Video conferencing) Business and Public Services (File sharing, Telemedicine, Distance learning) From a single provider (bundled services)! New technologies (ADSL+, VDSL, FTTN, FTTP) FTTP Market & Drivers Major Drivers for Broadband Access migration Political Pressure Worldwide access revolution taking place Europe must keep up with Asia and US Regulators and governments are actively stimulating new access technologies Competition Increasing competition in Europe (on bandwidth and triple play services) In some countries from CATV (NL, Belgium, Swiss) In many counties from competitive carriers using ULL FT is losing 60% of new DSL connections to the competition Other examples: UK, Spain, and starting in Germany and Italy all planning to provide triple play Reduce Cost Single integrated network for voice, video, data Easier installation, operation & maintenance Increase ARPU Increase bandwidth and coverage Overcome copper limitations Customer demand Retain and grow customer base Network renewal/replacement 89 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 FTTP Market & Drivers Bandwidth Needs Comparison of DSL, Cable and FTTH Technology Bandwidth Basic Triple is OK for approx 50-60% of households in Europe using ADSL video channel (4Mbit/s MPEG), Mbit/s Internet and VoIP = 5Mbit/s Commercial services: Telefonica, France Telecom, FastWeb, Free Telecom Many Service Providers target 0 Mbit/s HDTV with MPEG4, multi video channels, 5-0Mbit/s for Internet services Telemedicine, VPNs, video conferencing for business customers Also require at least Mbit/s upstream (peer to peer traffic) Coverage should be >80% Which technologies can accommodate this bandwidth need? Source: Belgacom Presentation at IIR Conference in Barcelona, Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

50 Why Fiber Now? The Broadband Access Network Evolution - Migration options Worldwide acceptance, standardization & mass market for: IP-based services IP/Ethernet based networks SFP-based optical Ethernet technologies (IEEE 80) Standard Single Mode Fiber (SMF - G.65) Passive Optical Network (PON) standards Technical improvements have driven down the costs of all FTTx components QoS and reliability of (optical) Ethernet networks Processor power & link speed Signal processing Cable installation FTTx economics Need case-by-case business case to compare CAPE of all FTTx technologies and bandwidth options Density, housing, cabling, trenching, CO and access equipment, CPE, CPE installation For greenfield or renewal FTTx already serious alternative (the cost of laying fiber is the same as that of laying copper) Re-use of existing copper makes a big cost difference and remains strong argument for DSL 9 Cours Réseaux Optiques Partie I March 008 Option : Extend fiber to the user Fiber-to-the-Node (FTTN) shorten copper loop Fiber-to-the-Premises (FTTP) no copper loop Central Office Access/ Distribution Fiber-fed DLC & ADSL Deep Fiber Node DLC & VDSL End-to-end copper Option : Enhance CO-based DSL Increase DSL speed and/or reach (ADSL+, VDSL, ) 94 Cours Réseaux Increase Optiques DSLAM Partie I March capacity 008 & performance Fiber to the Premises Fiber to the curb Fiber to the MDU End-user Fiber Drop Fiber or copper Drop Fiber Drop - Retrofit Copper Drop Fiber Drop - Retrofit Copper Drop Fiber Drop - Retrofit Copper Drop Copper Drop FTTP FTTN CO - DSL FTTP Basics FTTP Options FTT-Premises means home, office, MDU, building, etc. Typically within 00m of end-user Fiber or cat5 copper drops (native Ethernet, no DSL) FTTP brings huge benefits of fiber to access network, e.g.: Future proof investment Zero interference Virtually unlimited bandwidth, response to play (HDTV, VoIP, IA) Large distances Various FTTP technologies in the market: Active or Passive PP or PMP (PON) GPON or EPON (or BPON) Video digital in-band vs analog overlay Common characteristics: Native Ethernet based (in EMEA) Average bit-rate per user at least 0Mbps (up & down) Access line speed Mbps ITU G.98 BPON ITU G.984 GPON IEEE 80.ah EPON Ethernet PP DF ATM switch Multiservice switch OLT Ethernet Switch OLT Ethernet Switch Ethernet Ethernet PP -AON Switch. G or 6 Mb/s down. or.5 Gbps down, 55M.5Gbps up Gbps 00Bx N x Gbps or 0 Gbps t 55/6Mb/s up t n Optical power splitter t t n Optical power splitter t t n Optical power splitter Active Switch/Mux Mbps/sub Mbps/sub Mbps/sub Mbps/sub 8.5 Mbps per sub 5.7 Mbps/sub 00 Mbs per sub 00 Mbs per sub BPON = Broadband-PON ATM-only transport Standardized form available today, introduced in the 990s GPON = Gigabit -PON Native protocol transport using ATM, GFP/SDH, Ethernet Standardized in 004 EPON = Ethernet-PON Ethernet/IP -only transport In-band video Standardized in 004 Ethernet PP Direct Fiber (DF) Passive Outside plant Ethernet-only transport In-band video Standardized form available today AON = Active Optical Network Active Outside plant Ethernet-only transport In-band video Standardized form available today 95 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

51 Basics of PON Architecture Shared network, Tree topology with passive optical splitters No active electronics, lower costs and simplifies operations PHY specification dictates reach/bandwidth OLT: Optical Line Terminal, at Central Office ONU: Optical Network Unit, in CPEs OLT Downstream: Uses either ATM, TDM or Ethernet Framing and Line Coding QoS / Multicast support provided by Edge Router Upstream: TDMA protocol ONU sends packets in timeslots Must avoid timeslot collisions OLT 490nm Burstmode Optics BW allocation easily mapped to timeslots (MPCP) :N optical splitters (N dependent on PON technology) 0nm ONU ONU EPON vs GPON ITU (GPON) vs IEEE (EPON) Hot debate in the market, vendors taking position (whitepapers etc.) GPON benefits: Higher bitrates (up to.5gbps) Higher efficiency (more advanced MAC, less overhead) Supports native TDM, ATM, packet Operator Driven (FSAN): protection, security, long reach Mature Relies on B-PON foundations EPON benefits: Cheaper (control electronics) Uses regular Ethernet optics Claims TDM over Ethernet support Packet-only GPON compares to EPON Somewhat more expensive but offers more bandwidth and efficiency 97 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 PON vs E-PP / Active vs. Passive Solutions Comparison CO CPE CPE CPE PON CO SW AON CPE CPE CPE CO Ethernet Point to Point Passive Active Passive Less fibre Direct Fibre N+ transceivers N+ transceivers N transceivers Shared medium Dedicated links Dedicated links Expensive shared PON interface (optics and electrical) Less fibre Cheap interfaces (standard Ethernet) More fibre Cheap interfaces (standard Ethernet) Medium/Low CAPE Low CAPE Medium CAPE Low OPE Medium OPE Low OPE Low upgradability Medium upgradability Maximum upgradability CPE CPE CPE PON vs E-PP: application areas Both technologies are being explored and deployed throughout the world Both technologies have their merits and application areas Access networks are too varied for a single solution PON application examples: Long loop length Congested ducts PP application examples: Shared indoor access applications (MTU/Building/Business) When dedicated, upgradeable & secure bandwidth is required Shorter loop length, no congested ducts VDSL evolution towards AON Migration to direct fiber solutions Combines best of both worlds (passive and dedicated bandwidth) Fiber prices and installation techniques keep improving Maximum future proof 99 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

52 PON Technology Comparison IEEE 80.ah EFM Three Technologies in one Architecture Parameter BPON EPON GPON WDMPON Linerates 55, 6 Mbps,. Gbps fl.5 Gbps fl. Gbps or.4 Gbps fl Any 55 Mbps or 6 Mbps.5 Gbps 55, 6 Mbps,.,.4 Gbps EFMA and IEEE 80.ah Wavelengths nm fl nm (video-option) nm fl nm (video-option) nm fl ( fiber) nm fl ( fiber) nm Security Rudimentary (Churning) Not within 80.ah scope Secure (AES) Secure (λ) Physical reach Typical useable bandwidth per subscriber ( split) Max. 0 km Splits: : :8 5.9 Mbps Mhz RF fl Mbps Max. 0 km (0 km is option) Splits: : :64 5 Mbps fl 5 Mbps Max. 0 km (0 km is option) Splits: : :8 0 Mbps fl 0 Mbps Not yet standardized could use DWDM, CWDM or G.98. compatible λ plan Depends on laser technology used and channel spacing >00 Mbps fl >00 Mbps EMF-C EFM over point-topoint Copper: over existing copper wire (Cat-5) at speeds of 0 Mbps up to at least 750m, or Mbps up to 700m EFM-F EFM over point-topoint Fiber: over SMF at speeds of 00 and 000 Mbps up to at least 0 km EFM-P EFM over point-tomultipoint Fiber: EPON over SMF at a speed of up to Gbps, up to 0 km EFM-H mix of the above (e.g. FTTC) Dynamic BW Yes. ATM UNI signalling for Yes. Mandated but no Yes. Same as BPON for ATM MAC layer dependent CPE CPE Allocation PVCs supported signaling protocol mode. GEM mode TBD TDM support Yes Partial vendor specific Yes MAC layer dependent CPE Copper 0Mbps Fiber Gbps Optical Fiber Splitter Gbps Multicast support No Yes TBD No QoS ATM 4. Classes of Service 80.p priority queuing ATM 4. Classes of Service Depends on MAC layer 80. p, Diffserv TBD protocol Access Node Fiber Access 00Mbps Node Fiber Gbps Shared Access Node Management (OAM) Extensive message and MIB Still evolving Still evolving with BPON baseline λ OAM undefined, MAC defintion definitions layer dependent Standards ITU -T G.98. IEEE 80.ah EFM ITU -T G.984., CWDM ITU DWDM ITU 0 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Associated Ethernet OAM functions EFM Standards Scope vs. existing IEEE 80. standards Maximum Bandwidth (Symmetric) Existing IEEE 80. standards EFMC IEEE 80. ah EFMF IEEE 80. ah EFMP IEEE 80. ah 0Gbps Gbps 00Mbps 0Mbps Mbps 000BASE-S (MMF) 00BASE-T (Cat5) 0BASE-T (Cat5) 00BASE-F (MMF) 0PASS-TS (VDSL) 0GbE 000BASE-L (SMF) BASE-TL (SHDSL) 00BASE-L/B0 (SMF) 000BASE- B/L/P0 000BASE- P0 (SMF) 00m 500m 750m 000m 700m 5km 0km 0km Minimum Reach Overview of the Optical Market and Competition 0 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

53 Optical Networking Companies Total Optical Market Share 006 (pre-merge) ADVA FiberHome ADTRAN Fujitsu Alcatel-Lucent Hitachi Calient Huawei Ciena Infinera Cisco Lantern Corrigent Luminous Datang Mahi ECI Meriton Ericsson (Marconi) NEC Nokia Siemens Nortel Oki PacketLight Photonixnet Polaris RBN Sagem Samsung Sorrento/Zhone The top ten Optical Networking vendors control 85% of the market Sycamore Telco Systems Tellabs Transmode Tropic Turin Networks UTStarcom tera ZTE Source: Dell Oro Group Large equipment vendors generally have complete portfolio Smaller vendors target specific applications Market Share per product segment (ADM, OC, DWDM) can look very different 05 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008 Optical Market Revenue Comparison (005) by Product Group (post-merge) Spending by Region Source: Dell Oro Group Source: Dell Oro Group EMEA remains the largest region NAR is now approximately / of the pie AP is now about 0% larger than China CALA is 4% of the total TAM 07 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008

54 006 Optical Total Addressable Market Revenue Split by Segment Note: Carrier Ethernet not included The TAM estimate for 006 was approximately $9B The Traditional ADM and MSPP segments combined continue to represent about / of the market in 006. The contribution of each segment remains unchanged 09 Cours Réseaux Optiques Partie I March Cours Réseaux Optiques Partie I March 008