Trend in the standardization of
FCoPW and FC over MPLS
implementation
October 2006

Outline FCoPW
FCoPWOverview
Overview
 Standardization
StandardizationStatus
Status Encapsulation
Encapsulation
 Congestion
CongestionControlControl
 SummarySummary2

FC PW Overview
 FC PW allows the transport of point-to-point Fibre Channel to support
SAN extension and disaster recovery

 A new service for the Multi-Service transport network
 Key attributes• Transparency for separation of carrier and enterprise domains• Large distances• Reliable transport• Efficient transport by PSN statistical multiplexing3Motivation

MPLS NetworkPE
Fibre Channel

FC PW
Fibre Channel

EthernetPE

PPP/MLPPP

Ethernet PW

PEPEEthernet
Ethernet over TDM

TDM PW

Ethernet
TDM

TDM

KEY
TDM encapsulation

Fibre Channel PW encapsulation

Ethernet PW encapsulation

PPP/MLPPP – Ethernet Interworking - Ethernet PW encapsulation

MPLS Pseudowires

GFP/X.86 Termination – Ethernet PW encapsulation

4

FC Transport Methods
 FC over WDM• Limited distance• Not BW efficient FC over SONET/GFPT• Based on SONET/SDH transport network• No statistical multiplexing
 FC over IP• SAN-centric model• Necessitates TCP/IP network layers

5FC over PW Reference Model
Emulated Service
Pseudo Wire
PSN tunnel
PE2

PE1

PW1

CE1
FC_device

Customer
Edge 1

ProviderEdge 1

CE2
FC_device

ProviderEdge 2

Attachment circuit (AC)Native Fibre channel Port

Customer
Edge 2

Attachment circuit (AC)Native Fibre channel Port

Provider Edge
FCCE

Native Service
Processing

PW
Termination

PSN
Tunnel

MPLS
PSN

6

Standardization Status IETF PWE3 WG – PW termination• draft-ietf-pwe3-fc-encap-01.txt (June 2006)• Encapsulation methods• FC PW signaling• Congestion control• draft-ietf-pwe3-fc-encap-02.txt – in work to include mainlycongestion control details

7

Standardization Status T11 FC-BB WG – NSP functionality• FC-BB_PW is a work item in FC-BB-4• Credit management• Link Initialization• Login monitoring• Primitive Signals handling• Adaptation of FC information for PW transport8Encapsulation
 FC port traffic is carried transparently over a single PW
 FC information encapsulation• FC data frame is carried in one PW PDU• FC-BB_PW generated control frame (WAN flow control, Ping) iscarried in one PW PDU• FC Primitive Sequences are terminated at the local FC-BB_PW
and sent as single control frame• FC Primitive Signals (Idle, R_RDY) are terminated and handled atthe local FC-BB_PW
4Byte

PSN
Header

4Byte

PW Control
Label Word
PWE3 fields

4Byte

4Byte

24Byte0-2112Byte

4Byte

SRHeaderSOF

FrameHeader

PayloadCRC EOF

4Byte

Encapsulated FC frame
9Congestion Control
 Avoid frame loss as experienced by the CE Enable statistical multiplexing
QUEUEFC CERateShaper

FC FrameEncapsulation
SelectiveRetransmission
R_RDY
Queue depthmonitor
CreditManagement

Adaptive shaper
Monitorcontrol
frame loss10

Congestion Control
 Adaptive Rate Control• Guarantee minimum bandwidth (CIR)• Reduce loss probability by limiting bursts• Enhance efficiency by adapting to network conditions• Provide fairness between flows (TCP-friendly based on RFC3448)
 Selective Retransmission of lost frames• Enable in-order, no-loss transport• Allow efficient retransmission of lost frames• Provide congestion indications to the rate control mechanism• Standardized for FC transport in T11 FC-BB WG
11

Congestion Control
 Ingress queue management• Avoid received frame loss due to buffer overflow• Control credit management
 Credit management• Buffer-to-buffer credit handling with the CE• Performed as part of the NSP as standardized in T11 FC-FS WG

12

Implementation Example
 FC PW over Resilient Packet Ring
 Protected service over the ring
 Service is not degraded upon protection events
 Statistical multiplexing with Ethernet services

P-ADM
PTS

P-ADM
PTS

RemoteStorage

FC PW

P-ADM
PTS

P-ADMPTS

13

Summary FC PW benefits for a carrier:• Separation of SAN and Transport network domains• Very large distance (~1000 Km) to support disaster recovery• Reliable transport by packet retransmission• Efficient BW utilization by statistical multiplexing and repetitive
signal suppression• Low latency by MPLS-TE14

Questions?