1

Fibre Channel Introduction

91.560

2

High Level Overview Learning FC Structure and Concepts Understanding FC Protocol for SCSI

Objectives

3

Loop

FC-4 ULP Mapping

FC-3 Common Services

FC-2 Transport

FC-1 Transmission Protocol

FC-0 Physical Media

SCSI-3 ULP FC Levels

Overview

4

SCSI-3 Command Set Vs SCSI-2 Serial FC Transport Vs Parallel SCSI FC Link Services Arbitrated Loop Primitives

– Loop Initialization

– Arbitrate

– Open

– Close

Overview (cont)

5

Fibre or Copper Links (GLMs)– 133, 266, 531 and 1062 Megabaud

GLMRx

Tx

Overview (cont)

6

Topologies– N_Port

– F_Port

– NL_Port

– FL_PortNL_Port NL_Port

NL_Port NL_Port

Arbitrated Loop

N_PortN_Port

Point-To-Point

Overview (cont)

7

Topologies (cont)

N_PortN_Port F_PortF_Port

FL_PortF_PortN_Port NL_Port

Fabric

Overview (cont)

8

Transmission Character Ordered Set Frame

SOF (4)

EOF (4)

Data Field(0 to 2112)

CRC (4)

Header (24)

OptionalHeaders

Payload

FC Building Blocks

9

Frame (cont)– Frame Header Information

» Routing Control

» Destination ID

» Source ID

» Type

» Framing Control

» Sequence ID

» Data Field Control

» Sequence Count

» Originator ID

» Responder ID

» Parameter

FC Building Blocks (cont)

10

Frame (cont)– Frame Types

» FC-4 Device Data

» Extended Link Data

» FC-4 Link Data

Sequence Exchange

» Video Data

» Basic Link Data

» Link Control

ExchangeSequence Sequenc

eSequence

FrameFrameFrameFrameFrameFrame

FC Building Blocks (cont)

11

Flow Control– Buffer-to-Buffer Credit

» Link Level

– End-to-End Credit» Transport Level

– ULP Level

Communication Models– Full Duplex

– Half Duplex

FC-2 Transport Functions

12

Classes of Service– Class 1

» Supports EE Credit Flow Control

» No BB Credit Flow Control

» In Order Delivery Guaranteed

» Guaranteed Max. Bandwidth Between Two Nodes

FC-2 Transport Functions (cont)

13

Classes of Service (cont)– Class 2

» Referred to as Packet Switched in the Fabric Model

» Supports EE Credit Flow Control

» Supports BB Credit Flow Control

» In Order Delivery Not Guaranteed

» Allows for Better Use of Fabric Link Bandwidth

FC-2 Transport Functions (cont)

14

Classes of Service (cont)– Class 3

» No EE Credit Flow Control

» Supports BB Credit Flow Control

» Requires ULP Level Flow Control

» In Order Delivery Not Guaranteed

» Allows for Better Use of Fabric Link Bandwidth

» Added Performance Benefit of No ACKs

– Intermix» Unused Class 1 Bandwidth Used for Class 2 and 3

FC-2 Transport Functions (cont)

15

Block Management Data Reassembly Link Services

– Basic Link Services» ABTS

– Extended Link Services» Login, Process Login, Discovery, ...

FC-2 Transport Functions (cont)

16

Defines ULP Mapping to Send SCSI Information Defines Data Information Units

– FCP_CMND (unsolicited command)

– FCP_XFER_RDY (data descriptor)

– FCP_DATA (solicited data)

– FCP_RSP (command status)

Equates a SCSI IO Operation to an Exchange Equates the Associated SCSI Phases to Sequences

FC Protocol for SCSI

17

SCSI Write Operation

Loop

FCP_CMND

FCP_XFER_RDY

FCP_DATA

FCP_RSP

ARB

OPNCLS

SCSIULP

SCSIULP

FCTransport

FCTransport

Responder

Target

Originator

Initiator

NL_PortNL_Port

FC Protocol for SCSI (cont)

18

ULP Level– Task and Loop Management

Transport Level– Sequence and Link Service Management

Link Level– Link Management

FC Exception handling

19

ANSI x3T10: SCSI specifications ANSI x3T11: FC Specifications FCSI: Profiles FCA: Profiles Ad Hoc: Profiles

FC Committees

20

FC Physical and Signaling Interface (FC-PH) Arbitrated Loop (FC-AL) FC-AL Direct Attach SCSI Profile (Private Loop) Fibre Channel Protocol for SCSI (FCP) Peer Protocols’s “The Users Guide to Serial SCSI” Ancot’s “What is Fibre Channel” Ancot’s “Fibre Channel Volume One: The Basics”

FC References