Overhead Efficiency Analysis of Multi-Lane Alternatives

Transcription

1 Overhead Efficiency Analysis of Multi-Lane Alternatives IEEE 80.3 HSSG November 13-16, 006 Steve Trowbridge Lucent Technologies Maarten Vissers Alcatel Tel:

2 MAC Frame Format Framing used in 10G Base-R, 10G Base W , 000, 9600, Preamble SFD DA SA MAC SDU LT FCS IFG Transport network framing used in PDH, SONET/SDH, OTN , 000, 9600, GFP Header DA SA MAC SDU LT FCS Note: The Characteristic Information is the Payload plus the necessary information to delimit, forward, and check for accurate reception of the Payload IEEE 80.3 MAC adds minimum 0 octets per packet to characteristic information GFP Encapsulation of MAC frames adds minimum 8 octets per packet

3 Where are we today? 10 Gbit/s Ethernet Transport Native Ethernet (10G Base-R) using 64B/66B PCS Longer Reach Alternatives compatible with Transport Networks 10G Base-W Encode 64B/66B data into VC-4-64c (OC-19c) carried via STM-64/OC-19 OTN OTU with GFP framing, with or without optional FEC 3

4 Mapping of Ethernet MAC into VC-4-64c using 64B/66B coding 63 octets octets J1 B3 C G1 H1 H4 Fixed Stuff 64B/66B Data 9 rows Z3 Z4 Z octets 4

5 Mapping Payload Area into OTUk frame FAS & MFAS SM PM OTUk/ODUk/OPUk Overhead PSI GFP HDR DA SA M_SDU FCS GFP HDR SA M_SDU FCS GFP IDLE GFP HDR GFP IDLE OPUk payload area DA SA M_SDU FCS DA FEC OTUk FEC Added overhead bytes +0.4% of payload Optional FEC +6.7% of payload Not included in this analysis as FEC is additional to any approach 5

6 10 Gbit/s Ethernet Frame Format Alternatives 10G Base R 10G Base W OTU (no FEC) GFP Framing IEEE 80.3 MAC framing Gbit/s capacity for packet stream 64B/66B PCS Gbit/s physical layer IEEE 80.3 MAC framing Gbit/s capacity for packet stream 64B/66B PCS carried in VC Gbit/s physical layer (STM-64/OC-19) GFP framing Gbit/s capacity for packet stream OTN scrambler rather than 64B/6B PCS Gbit/s physical layer (without FEC) 6

7 Payload (DA, SA, LT, MAC SDU, MAC FCS) Throughput for 10 Gbit/s Alternatives Packet Payload Size 10G Base R Gbit/s 10G Base W Gbit/s OTU (no FEC) GFP Framing Gbit/s

8 Physical Layer Aggregation via mentation Option 1 Preamble as payload , 000, 9600, Preamble SFD DA SA MAC SDU LT FCS IFG 1 8, 16, 3, , 16, 3, 64 PCS 1 ment 1 ment n+1 1 8, 16, 3, , 16, 3, 64 PCS ment ment n+ PCS n 1 8, 16, 3, 64 ment n 1 8, 16, 3, 64 ment n Assume that last fragment can be shortened 8

9 Inverse Multiplexing for ODUk Virtual Concatenation (VCAT) 14X+1 14X+ 15X 15X+1 15X+ 16X 383X+1 384X Ultra-high rate bit stream GFP HDR DA SA M_SDU FCS OPUk-Xv OH (8 X bytes) OPUk-Xv Payload ( X bytes) VCAT overhead included in 0.4% overhead of each lane. Payload capacity scales linearly with number of lanes VCOH PSI 16 OPUk OH 3 VCOH 4 PSI OPUk Multiple OH lower rate streams for transport across network 384 OPUk Payload ( bytes) OPUk #1 OPUk Payload ( bytes) OPUk #X OPUk-Xv Consecutive bytes of original bitstream are distributed to each lane of the VCAT group. No packet can be retrieved from only one lane. 9

10 Option 1 Physical Layer Aggregation, Carry Preamble, 64B/66B PCS for lanes OH percentage ment Size ODU VCAT % 6.56% 17.19% 1.50% 1.97% Packet Payload Size % 3.46% 13.9% 8.1% 7.3% %.4% 1.97% 8.34% 1.97% %.10% 1.61% 7.87% 0.95% %.01% 1.64% 7.88% 0.8% % 1.90% 1.51% 7.83% 0.50% % 1.89% 1.51% 7.8% 0.46% 10

11 Option 1 Physical Layer Aggregation, Carry Preamble, 64B/66B PCS for lanes 10x10G Lane Throughput Packet Payload Size 10x10G Base-R ment Size x ODU VCAT

12 Physical Layer Aggregation via mentation Option do not transmit preamble , 000, 9600, Preamble SFD DA SA MAC SDU LT FCS IFG 1 8, 16, 3, , 16, 3, 64 PCS 1 ment 1 ment n+1 1 8, 16, 3, , 16, 3, 64 PCS ment ment n+ PCS n 1 8, 16, 3, 64 ment n 1 8, 16, 3, 64 ment n For apples to apples comparison with other approaches that do not carry preamble Note that clause 61 PME aggregation does not carry the preamble1

13 Option Physical Layer Aggregation, Do not transmit Preamble, 64B/66B PCS for lanes OH percentage ment Size ODU VCAT % 1.88% 1.50% 7.81% 1.97% Packet Payload Size % 3.46% 13.9% 8.1% 7.3% %.4% 1.97% 8.34% 1.97% % 1.90% 1.61% 7.87% 0.95% %.01% 1.64% 7.88% 0.8% % 1.90% 1.51% 7.83% 0.50% % 1.88% 1.51% 7.8% 0.46% 13

14 Option Physical Layer Aggregation, Do not transmit Preamble, 64B/66B PCS for lanes 10x10G Lane Throughput 10x10G Base-R - ment Size x ODU VCAT Packet Payload Size

15 Conclusions/Follow on work Physical Layer Aggregation based on Clause 61 most efficient for small packets using large fragments OTN/GFP framing has some attractive features over traditional MAC Lightweight, minimal overhead approach Built-in VCAT capability to build flexible multi-lane groups with linear capacity scaling Option for FEC which is likely required for longer reach interfaces Seamless interoperability with transport networks Is it time to consider dropping the inter-frame gap for full-duplex interfaces? 15