Broadband Networks Virgil Dobrota Technical University of Cluj-Napoca, Romania

Transcription

1 Broadband Networks Virgil Dobrota Technical University of Cluj-Napoca, Romania Copyright Virgil Dobrota , All rights reserved 1

2 Course 12 - Outline 46. NGN Next Generation Networks Copyright Virgil Dobrota , All rights reserved 2

3 47. NGN Next Generation Networks Copyright Virgil Dobrota , All rights reserved 3

4 NGN Next Generation Networks (I) ITU-T s Definition of NGN [Rec. Y.2001] a packet-based network telecommunications services to users multiple broadband + QoS-enabled transport technologies service-related functions independent of the underlying transport-related technologies unfettered access for users to: networks service providers services generalised mobility consistent and ubiquitous provision of services to users support of multiple last mile technologies Copyright Virgil Dobrota , All rights reserved 4

5 NGN Next Generation Networks (II) through strategic 21CN domains 5

6 NGN Next Generation Networks (III) Access domain Multi-service access nodes (MSANs) aggregate the voice, data and video services from end users on to the 21CN core IP-based network. replace the service-specific equipments of the legacy network (System X and AXE10 concentrators for PSTN and ISDN and DSLAMs for broadband). Approximately 5,500 BT sites in the UK will house MSANs with Fujitsu and Huawei selected as suppliers. Copper MSANs - terminate the copper cables from end user customers Fibre MSANs - terminate the fibre cables from many business sites. 6

7 NGN Next Generation Networks (IV) Metro node provides the IP routing, Ethernet switching, SDH switching and gateways to existing networks for the unified 21CN network for voice, data and video. approximately 100 metro nodes in the UK with Alcatel, Cisco and Siemens selected to provide the technology includes Provider edge IP routers; Ethernet switches; media servers; trunk media gateways and session border controllers. 7

8 NGN Next Generation Networks (V) Core node the high capacity, large scale routers providing cost efficient connectivity between metro nodes approximately 20 core nodes in the UK with Cisco and Lucent selected to provide the technology, MPLS routers. 8

9 NGN Next Generation Networks (VI) i-node where the service execution functionality is located - in essence the intelligence that controls services. includes soft switches, network intelligence and bandwidth management capabilities. approximately 10 i-nodes in the UK with Ericsson selected to provide the technology for the control of voice services which includes call servers; application servers and signalling gateways. 9

10 NGN Next Generation Networks (VII) Transmission includes the optical fibre transport infrastructure that connects all nodes in 21CN but also the electronics that convert the signals carried at high capacity over the cables connecting the MSANs, metro and core nodes. much of the optical fibre infrastructure is already in place and Ciena and Huawei have been selected to provide the electronics which include WDM and high bit-rate SDH cross connects. 10

11 NGN Next Generation Networks (VIII) Technologies and protocols 11

12 NGN Next Generation Networks (IX) Technologies and protocols Ethernet IMS (Internet Protocol Multi-media Sub-system) IP (Internet Protocol) MPLS (Multi-Protocol Label Switching) SDH (Synchronous Digital Hierarchy) SIP (Session Initiation Protocol) VLAN (Virtual Local Area Network) WDM (Wave Division Multiplexing) 12

13 NGN Next Generation Networks (X) Ethernet BT GigeStream, a low cost, point-to-point Ethernet private circuit service available nationally at speeds of between 250 Mbps and 1 Gbps BT EVLAN, a VPLS-based metro any-to-any Ethernet LAN service BT Enterprise Ethernet, a new low bandwidth version of MegaStream Ethernet that will offer many of the characteristics of a traditional private circuit, but with the benefit of a low cost Ethernet interface. 13

14 NGN Next Generation Networks (XI) IMS (Internet Protocol Multi-media Sub-system) originally designed for the mobile industry to add a common session layer on top of the IP network layer to support many different applications. standardised for the mobile industry by 3GPP (3G Partners Program). standardised for fixed networks by ETSI TISPAN, adding AAA and QoS control 14

15 NGN Next Generation Networks (XII) IP (Internet Protocol) end-to-end network protocol for all types of communication and applications (now and in the future) 15

16 NGN Next Generation Networks (XIII) MPLS (Multi-Protocol Label Switching) to maximise efficiency, it allows different services - for example, voice, audio and video calls - to be assigned their own portion of the capacity on the links between metro nodes and for that portion to be given the appropriate prioritisation essential protocol for converged IP networks it ensures that voice is prioritised over less time-critical data 16

17 NGN Next Generation Networks (XIV) SDH (Synchronous Digital Hierarchy) provides transmission pipes between the network nodes (typically at 2.5Gbps or 10 Gbps), although lower speeds of 155 Mbps and 622 Mbps are also used The pipes -> into smaller pipes (pipes within pipes) of 2, 34, 45, 150 and multiples of 150 Mbps and these smaller pipes can be switched at network nodes using SDH cross-connects to form an end-to-end connection across the network very suitable for leased lines ring or mesh topologies protection and restoration to improve network resilience 17

18 NGN Next Generation Networks (XV) SIP (Session Initiation Protocol) 'signalling' standard for setting up a session across an IP network originally standardised by IETF a framework of messages that can be exchanged between two endpoints (user, machine or source of content) to establish a session before media flows between them using IP. Higher layer applications at the edge of the network can set paths up across the network using SIP. intelligence in the network allows service providers to offer presence based routing of calls for their customers. 18

19 NGN Next Generation Networks (XVI) VLAN (Virtual Local Area Network) LAN -> a network of Ethernet links connecting together the computers, servers and printers of an enterprise (single site). WAN -> LANs can be extended geographically VLANs -> a common Ethernet switched network in which the links can be partitioned to provide capacity for several individual LANs. VLANs allow us to partition the capacity of the links according to the needs of the different types of service, for example, voice and video. 19

20 NGN Next Generation Networks (XVII) WDM (Wave Division Multiplexing) a multiplexing technology used for fibre acts like a prism, separating the light in the fibre into different coloured beams - or different wavelength channels CWDM (Coarse WDM) - the wavelengths are spaced well apart which means lower cost optical transmitters and receivers can be used but the number of wavelengths is relatively small. DWDM (Dense WDM ) - much larger number of closely spaced wavelengths but requires more costly transmitters and receivers. 20

21 NGN Next Generation Networks (XVIII) Voice call path - today Voice call path - tomorrow MSAN - Multi-Service Access Node, i-node software that controls the services Metro node routing and signalling 21

22 NGN Next Generation Networks (XIX) Broadband - today DSLAM - Digital Subscriber Line Access Multiplexer ATM - Asynchronous Transfer Mode ISP - Internet Service Provider Broadband - tomorrow MSAN - Multi-Service Access Node Metro node routing and signalling 22

23 NGN Next Generation Networks (XX) Voice to Communications Provider - today Voice to Communications Provider - tomorrow 23