2. What is all this Concatenation stuff anyway? ”Bandwidth efficiency" Huub van Helvoort Member of Technical Staff Lucent Technologies email: hhelvoort@lucent.com Concatenation Tutorial © Lucent Technologies 2002 T1X1.5 presentation T1X1.5/2002-096

3. 2 © 2002 Lucent Technologies Concatenation Tutorial Contents Bandwidth growth Rate Comparison Virtual Concatenation Link Capacity Adjustment Scheme (LCAS) Application Standards 2

4. 3 © 2002 Lucent Technologies Concatenation Tutorial Bandwidth growth Rate Comparison Virtual Concatenation Link Capacity Adjustment Scheme (LCAS) Application Standards 3

5. 4 © 2002 Lucent Technologies Concatenation Tutorial SDH mapping scheme Initial mappingMore MultiplexingContiguous Concatenation 4 C-4-64c C-4-256c C-4-16c C-4-4cAU-4-4cVC-4-4c AU-4-16cVC-4-16c AU-4-64cVC-4-64c AU-4-256cVC-4-256c x 1 AUG-64 AUG-256 AUG-16 AUG-4 STM-256 STM-64 STM-16 STM-4 x 1 x 4 C-4 C-3 C-2 C-12 C-11VC-11 VC-12 VC-2 VC-3 TUG-2TU-2 STM-0 AUG-1 VC-3 TUG-3 VC-4 AU-3 TU-11 TU-3 AU-4STM-1 x 1 x4 x 3 x 7 pointer processing multiplexing aligning mapping x 3 TU-12

6. 5 © 2002 Lucent Technologies Concatenation Tutorial SDH mapping scheme Contiguous Concatenation (i.e.VC-4-Xc) provides a payload area of X Container-4, see figure 5 125  s X  260 C-4-Xc X  261 VC-4-Xc 1 9 J1 B3 C2 G1 F2 H4 F3 K3 N1 1 X-1 fixed stuff has one common set of POH, in the first column, used for the whole VC-4-Xc (e.g. BIP-8 covers all 261  X columns of a VC-4-Xc) columns #2 to #X are fixed stuff

7. 6 © 2002 Lucent Technologies Concatenation Tutorial SDH mapping scheme Contiguous Concatenation a VC-4-Xc is transported in X contiguous AU-4 in the STM-N signal 6 the first column of the VC-4-Xc is always located in the first AU-4 the pointer of this first AU-4 indicates the position of the J1 byte of the VC-4-Xc. The pointers of AU-4 #2 to #X are set to the concatenation indication to indicate a contiguously concatenated payload pointer justification is performed in common for the X concatenated AU-4s and X  3 stuffing bytes are used.

8. 7 © 2002 Lucent Technologies Concatenation Tutorial Bandwidth growth Rate Comparison Virtual Concatenation Link Capacity Adjustment Scheme (LCAS) Application Standards 7

9. 8 © 2002 Lucent Technologies Concatenation Tutorial Rate Comparison C-11 C-12 C-2 C-3 C-4 C-4-4c C-4-16c SDH - TDM 1.600 Mbit/s 2.176 Mbit/s 6.784 Mbit/s 49.536 Mbit/s 149.760 Mbit/s 599.040 Mbit/s 2.396 160 Mbit/s C-4-64c9.584 640 Mbit/s Ethernet ATM ESCON Fibre Channel Fast Ethernet Gigabit Ethernet Data 10 Mbit/s 25 Mbit/s 200 Mbit/s 400 Mbit/s 800 Mbit/s 100 Mbit/s 1 Gbit/s 10 Gb Ethernet10 Gbit/s C-4-256c38.338 560 Mbit/s SDH container size/bit-rates vs. Data bit-rates 8

10. 9 © 2002 Lucent Technologies Concatenation Tutorial Rate Comparison C-3 C-4 C-4-4c C-4-16c SDH 20% 50% 67% 33% 67% 33% 42% C-4-64c100% Ethernet ATM ESCON Fibre Channel Fast Ethernet Gigabit Ethernet Data 10 Mbit/s 25 Mbit/s 200 Mbit/s 400 Mbit/s 800 Mbit/s 100 Mbit/s 1 Gbit/s 10 Gb Ethernet10 Gbit/s Efficiency Transport efficiencies the solution: Virtual Concatenation 9

11. 10 © 2002 Lucent Technologies Concatenation Tutorial Bandwidth growth Rate Comparison Virtual Concatenation Link Capacity Adjustment Scheme (LCAS) Application Standards 10

12. 11 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation Why: to transport contiguous concatenated signals in a network with NEs that do not support VC-n-Xc Prerequisites: no requirements on existing NEs that transit VC-ns part of a Virtual Concatenation Group (VCG or VC-n-Xv) 11 to provide a better bandwidth granularity to transport the new services with non-SDH bit rates no strict routing constraints for operators by compensating the differential delay caused by difference in optical path length

13. 12 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation Mapping of C-n-Xc into X  VC-n: a VC-n-Xv 12 125  s m+11 1 9 VC-n#X overhead VC-n-Xv 125  s C-n-Xc 1 9 1 X  m X 125  s m+11 1 9 VC-n#1 overhead

14. 13 © 2002 Lucent Technologies Concatenation Tutorial C-n-Xc C-n 1 2 X X  VC-n = VC-n-Xv Virtual Concatenation VC-n-Xc transport through a VC-n only network 13

15. 14 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation Differential delay is caused by: geographically large ring with VC-ns from the same VC-n-Xv routed around the ring in different directions, delay is mainly due to fiber propagation (~5  s/km) 14

16. 15 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation networks with diversely routed path protected VC-ns, delay is mainly due to fiber propagation (~5  s/km) 15

17. 16 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation Provides additional transport sizes: C-11-Xc C-12-Xc C-3-Xc C-4-Xc container 1 - 63 1 - 256 1.6 Mbit/s 2.0 Mbit/s 49 Mbit/s 150 Mbit/s Xin steps of 100.8 Mbit/s 137.1 Mbit/s 12.7 Gbit/s 38.3 Gbit/s up to 16

18. 17 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation C-12-5c C-12-12c C-12-46c C-3-2c C-3-4c C-3-8c C-4-6c C-4-7c SDH 92% 98% 100% 89% 95% C-4-64c100% Ethernet ATM ESCON Fibre Channel Fast Ethernet Gigabit Ethernet Data 10 Mbit/s 25 Mbit/s 200 Mbit/s 400 Mbit/s 800 Mbit/s 100 Mbit/s 1 Gbit/s 10 Gb Ethernet10 Gbit/s Efficiency Transport efficiencies 17

19. 18 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation Operation: 18 distribute the payload to be transported bytewise over the members in the VCG provide byte alignment required for re-alignment after diverse routing delay compensation use the alignment indicator of each member to determine the experienced differential delay

20. 19 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation from source (So) to sink (Sk): Virtual Concatenation overhead: 19 Multi Frame Indicator (MFI) the MFI is used to determine at the Sk the differential delay and re-align the received data to reconstruct the original Sequence Indicator (SQ) at the So each VC-n in the VCG is assigned an unique identifier to be used at the Sk for reconstruction of the original signal

21. 20 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation Higher order overhead VC-4/3 POH H4 20

22. 21 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation Lower order overhead 21

23. 22 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation Benefits: not restricted to the situation in which all the individual VC-ns are contained within a single Multiplex Section 22 is transparent to intermediate network Elements, therefore it can be cost effectively deployed into an existing network without the need to upgrade all NEs can use protection schemes inherited from SDH per VC-n operators get the ability to implement channels that are more appropriate for the new router based applications by providing bandwidth granularity, right sized capacity, efficient mapping, traffic scalability and channelized high capacity SDH interfaces

24. 23 © 2002 Lucent Technologies Concatenation Tutorial Virtual Concatenation Points for improvement: if one of the VC-n of a virtual concatenation group VC-n-Xv fails, the whole VCG fails the solution: LCAS 23 data transport can have a variable requirement for bandwidth regarding the time of the day, or the day of the week

25. 24 © 2002 Lucent Technologies Concatenation Tutorial Bandwidth growth Rate Comparison Virtual Concatenation Link Capacity Adjustment Scheme (LCAS) Application Standards 24

26. 25 © 2002 Lucent Technologies Concatenation Tutorial LCAS provides the capability of temporarily removing member links that have experienced a failure Features: 25 Prerequisites: LCAS assumes that in cases of capacity initiation, increase or decrease, the construction or destruction of the end-to-end path of each individual member is the responsibility of the Network and Element Management Systems. located in the virtual concatenation source and sink adaptation functions only provides a control mechanism to hitless increase or decrease the capacity of a VCG link to meet the bandwidth needs of the application

27. 26 © 2002 Lucent Technologies Concatenation Tutorial LCAS Operation: use virtual concatenation operation for differential delay compensation and de/re-construction of payload 26 synchronization of changes in the capacity of the transmitter (So) and the receiver (Sk) shall be achieved by a control packet each control packet describes the state of the link during the next control packet changes are sent in advance, so that the receiver can switch to the new configuration as soon as it arrives.

28. 27 © 2002 Lucent Technologies Concatenation Tutorial LCAS In the forward direction, So to Sk: Multi Frame Indicator (MFI) Sequence Indicator (SQ) Control (CTRL): IDLE - ADD - NORM - EOS - DNU - FIXED Group Identification (GID) In the return direction, Sk to So: Member Status (MST) Re-Sequence Acknowledge (RS-Ack) For both directions: Cyclic Redundancy Check (CRC) over the control packet Note: MST and RS-Ack are identical in the control word of ALL members of the same VCG Control packet content, LCAS overhead: 27

29. 28 © 2002 Lucent Technologies Concatenation Tutorial LCAS Control packet content 28 information of member_n in VCG_a information sent in control packet x of member_n in VCG_a

30. 29 © 2002 Lucent Technologies Concatenation Tutorial LCAS 29 So side process

31. 30 © 2002 Lucent Technologies Concatenation Tutorial LCAS 30 Sk side process

32. 31 © 2002 Lucent Technologies Concatenation Tutorial LCAS Higher order overhead 31

33. 32 © 2002 Lucent Technologies Concatenation Tutorial LCAS Lower order overhead 32

34. 33 © 2002 Lucent Technologies Concatenation Tutorial LCAS Add two new members to the VCG 33 ADD ADD SQ=5ADD SQ=6 MST=OK NORM SQ=4EOS SQ=5 NORM SQ=5EOS SQ=6 (EOS SQ=4) IDLE MST=OK RS-Ack OK FAIL ADD SQ=6

35. 34 © 2002 Lucent Technologies Concatenation Tutorial LCAS Remove one (last) member from the VCG 34 REMOVE EOS SQ=3 (NORM SQ=3)(EOS SQ=4) IDLE MST=FAIL RS-Ack IDLE SQ>3 OK FAIL IDLE REMOVE

36. 35 © 2002 Lucent Technologies Concatenation Tutorial LCAS Remove two members (not last) from the VCG 35 REMOVE IDLE SQ>3 MST=FAIL EOS SQ=3 (NORM SQ=3)(NORM SQ=4)(EOS SQ=5) MST=FAIL RS-Ack IDLE SQ>3 OK FAIL REMOVE IDLE

37. 36 © 2002 Lucent Technologies Concatenation Tutorial LCAS 36 FAILED (NORM SQ=3) NORM SQ=4 (EOS SQ=5) MST=FAIL DNU SQ=4 CLEAR MST=OK NORM SQ=4 traffic hit decreased capacity Network failure: temporarily remove a (not last) member from the VCG OK FAIL OK

38. 37 © 2002 Lucent Technologies Concatenation Tutorial LCAS Network failure: temporarily remove last member from the VCG 37 FAILED EOS SQ=3 (NORM SQ=3) EOS SQ=4 MST=FAIL DNU SQ=4 CLEARNORM SQ=3 MST=OK EOS SQ=4 traffic hit decreased capacity OK IDLE FAIL OK

39. 38 © 2002 Lucent Technologies Concatenation Tutorial Bandwidth growth Rate Comparison Virtual Concatenation Link Capacity Adjustment Scheme (LCAS) Application Standards 38

40. 39 © 2002 Lucent Technologies Concatenation Tutorial Mapping Data SDH, SONET and OTN provide fixed rate channels, with virtual concatenation and LCAS to provide the best match 39 to map the different types of Data into a fixed rate channel a new mechanism is defined: Generic Framing Procedure (GFP) i.e. ITU-T recommendation G.7041/Y.1303 GFP is a generic mechanism to carry any packet signal (Ethernet, Fiber channel, ESCON) over fixed rate channels VC-n, VC-n-Xc, VC-n-Xv and LCAS providing flexible adjustment of a VC-n-Xv channel most Data transport is packet based

41. 40 © 2002 Lucent Technologies Concatenation Tutorial Generic Framing Procedure 40 EthernetIP/PPP Fibre Channel FICONESCON other client signals SDH/SONET pathOTN pathother CBR path GFP - Client Specific Aspects (payload dependent) GFP - Common Aspects (payload independent)

42. 41 © 2002 Lucent Technologies Concatenation Tutorial Generic Framing Procedure 41 PLI: PDU Length Indicator PDU: Protocol Data Unit cHEC: core - Header Error Control FCS: Frame Check Sequence (optional) When no frames/characters are received, idle frames are inserted. Transparent (8B/10B) Mapped: Individual characters of the client signal are mapped into fixed-length GFP frames. Frame Mapped: Client frames are mapped into GFP frames. PLI cHEC (FCS) PLI GFP Frame GFP payload 4 - 65535 payload header Client PDU 00 cHEC Idle Frame cHEC

43. 42 © 2002 Lucent Technologies Concatenation Tutorial Bandwidth growth Rate Comparison Virtual Concatenation Link Capacity Adjustment Scheme (LCAS) Application Standards 42

44. 43 © 2002 Lucent Technologies Concatenation Tutorial Standards 43 Concatenation Link Capacity Adjustment Scheme (LCAS) Generic Framing Procedure (GFP) Equipment Equipment Management Function G.707 (10/2000) corr 1, corr 2*, add 1* G.7042/Y.1305 (11/2001)* G.7041/Y.1303 (11/2001)* G.783 (02/2001)* G.709 (02/2001) G.798 (11/2001) ITU-T

45. 44 © 2002 Lucent Technologies Concatenation Tutorial Standards Concatenation, contiguous, virtual + LCAS (equipment Specific) generic LCAS, refers to ITU generic GFP, refers to ITU T1.105* G.7042* G.7041* 44 EN 300 417-9-1 Concatenation, contiguous, virtual ETSI ANSI

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