Workshop - New Paradigms for Routing in Optical Networks

Workshop - New Paradigms for Routing in Optical Networks Efficient routing for high capacity, flexible optical networks with different classes of service Douglas Aguiar July 2015 padtec.com

Summary 1. Photonic Networks 2. Classes of Service in Optical Networks 3. Routing for Optical Restoration 4. The Future and its Challenges 2

Summary 1. Photonic Networks 2. Classes of Service in Optical Networks 3. Routing for Optical Restoration 4. The Future and its Challenges 3

1 Photonic Networks Photonic Networks Photonic network Lightpath Optical network able to route lightpaths Optical path inside a photonic nework Even in today s quasi-static networks ROADMs provide the efficient use of the network capacity 4

1 Photonic Networks Topology virtualization With proper planning complex topologies with virtual point to point links can be established DWDM layer Physical layer Traffic growth uncertainty can be more effectively addressed (Traffic Engineering) Imposes greater complexity during network planning. Allow the planning of complex protection architectures 5

1 ROADM site building block Photonic Networks Wavelength Selective Switches (WSS) are key elements for current ROADM architectures. Flexgrid capability (ITU-T G.694.1) Switching time Port to port isolation 6

Splitter WSS Mux Demux 1 Photonic Networks ROADM architecture Broadcast and Select Architecture Multifiber Patch Cord Direction Interconnection Structure WSS Optical Full Mesh Splitter Single Fiber Patch Cord WSS Splitter Line Interface Short reach Interface Mux Demux CDC Demux CDC Mux Mux Demux Optical Amplification Client Equipment* *IP Router, SDH ADM Transponders Transponders Long reach Interface Add/drop interface 7

Summary 1. Photonic Networks 2. Classes of Service in Optical Networks 3. Routing for Optical Restoration 4. The Future and its Challenges 8

2 Classes of service in optical networks Typical classes of service Unprotected service (1+0) Restorable service (1+R) Protected service (1+1) Protected and restorable service (1+1+R) 9

2 Unprotected service (1+0) Classes of service in optical networks 1. Two unprotected services with possible protection provided by client layer; 2. Possible to allocate a 1+0 service disjoint to an already provisioned service. 10

2 Restorable service (1+R) Classes of service in optical networks RSVP-TE Signaling For GMPLS Restoration LSP draft-gandhi-ccamp-gmpls-restoration-lsp-03 1. Restoration LSP is signaled after the failure of the working LSP is detected. 2. Restoration LSP may share resources with the failed working LSP. 11

2 Protected service (1+1) Classes of service in optical networks 1. Two disjoint LSPs are established 2. Traffic is transmitted through both paths 3. In case of failure both receivers switch to the protection LSP 12

2 Protected and restorable service (1+1+R) Classes of service in optical networks RSVP-TE Signaling For GMPLS Restoration LSP draft-gandhi-ccamp-gmpls-restoration-lsp-03 1. Restoration LSP is signaled after the failure of the working LSP and/or protecting LSP; 2. Restoration LSP may share resources with the failed working/protecting LSP; 3. Restoration LSP provides protection against a second order failure for 1+1+R. 13

Summary 1. Photonic Networks 2. Classes of Service in Optical Networks 3. Routing for Optical Restoration 4. The Future and its Challenges 14

3 Planning for the DWDM layer Routing for Optical Restoration Physical Layer BSA (16) BSA (16) FTL (10) 10 FTL (10) 1+R 100G Services SPO (06) RJO (05) PAE (01) BHZ (07) CCR (14) SPO (06) 10 10 RJO (05) 10 10 10 PAE (01) 4 BHZ (07) 4 4 CCR (14) 4 4 MNS (20) 4 4 4 BSA (16) BSA (16) FTL (10) 1 1+1+R 100G Services FTL (10) SPO (06) RJO (05) PAE (01) BHZ (07) CCR (14) SPO (06) 1 5 RJO (05) 5 5 5 PAE (01) 1 BHZ (07) 5 1 CCR (14) 1 1 MNS (20) 5 1 1 15

3 Planning for the DWDM layer Routing for Optical Restoration Physical Layer DWDM Layer 16

3 Routing for Optical Restoration Efficient Network Planning In order to maximize restoration availability and minimize cost, one can make use of: Efficient Routing and Wavelength Assignment algorithms Regeneration pools 17

Summary 1. Photonic Networks 2. Classes of Service in Optical Networks 3. Routing for Optical Restoration 4. The Future and its Challenges 18

4 The future and its challenges Technologies Flexible transponders Software Defined Networks Spatial Division Multiplexing 19

4 Physical dimensions The future and its challenges Peter J. Winzer, Making spatial multiplexing a reality Nature Photonics 8, 345 348 (2014) 20

4 Flexible transponders The future and its challenges Advanced and flexible modulation formats allow to balance between Reach Performance Spectral occupation Modulation Format Spectral efficiency [bit/s/hz] Bits per symbol OOK 0,5 1 BPSK 0,5 1 1 bit/symbol OOK 2 x 3 bit/symbol DP-8QAM 2 x 1 bit/symbol DP-BPSK 2 x 4 bit/symbol DP-16QAM 2 x 2 bit/symbol DP-QPSK QPSK 1 2 16-QAM 2 4 DP-QPSK 2 4 DP-16QAM 4 8 21

4 Software Defined Networks The future and its challenges Centralized control benefits Simpler HW Open to third party development EMS/NMS Dados Dados Dados Centralized control via EMS/NMS in transport networks But transport networks has always been centralized (!) Differences are: Standards (??) Open to third party SDN Dados Dados Dados Centralized control via SDN in transport networks CP CP CP Dados Dados Dados Distributed control in packet networks 22

4 The future and its challenges Spatial Division Multiplexing Bandwidth growth need is a fact To achieve Tbps channels SDM might be useful. D. J. Richardson, J. M. Fini & L. E. Nelson, Spacedivision multiplexing in optical fibres, Nature Photonics 7, 354 362 (2013) 23

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Direction A 1 ROADM interfaces Photonic Networks Line interfaces Direction C IS* Direction E Colorless (C) Any port in any unrepeatered wavelength Directionless (D) Any port to any direction A/D 1 A/D 2 A/D n Contentionless (C) Any port in any wavelength Add/drop interfaces *Interconnection Structure 25

Transponder Transponder 8x5 Multicast Swicth To/From direction A To/From direction B From direction B From direction A To direction B To direction A 1 Photonic Networks ROADM Add/Drop interfaces Colorless, Directionless and Contentionless interfaces Sp Sp Sp Sp Sp WSS Sp Sp Sp Sp Sp Sw Sw Sw Sw Sw Sw Sw Sw Sw Sw Sw Sw Sw Sw Sw Sw Splitter CDC Demux Splitter Coupler CDC Mux Colorless and Directionless interface CDC interface for 8 channels in a 5 degree ROADM Node CD interface for 8 channels in a 5 degree ROADM Node 26

4 The future and its challenges Flexible transponders and networks Flexible grid Superchannels Network defragmentation Interference in Colorless interfaces 27