Fibre Channel Introduction

1
Fibre Channel Introduction

• 91.560

2
Objectives

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

3
Overview

• FC Levels

4
Overview (cont)

• SCSI-3 Command Set Vs SCSI-2
• Serial FC Transport Vs Parallel SCSI
• FC Link Services
• Arbitrated Loop Primitives
• Loop Initialization
• Arbitrate
• Open
• Close

5
Overview (cont)

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

6
Overview (cont)

• Topologies
• N_Port
• F_Port
• NL_Port
• FL_Port

7
Overview (cont)

• Topologies (cont)

8
FC Building Blocks

• Transmission Character
• Ordered Set
• Frame

Data Field (0 to 2112)
CRC (4)
Header (24)
SOF (4)
EOF (4)
Optional Headers
Payload
9
FC Building Blocks (cont)

• 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

10
FC Building Blocks (cont)

• Frame (cont)
• Frame Types
• FC-4 Device Data
• Extended Link Data
• FC-4 Link Data
• Sequence
• Exchange

• Video Data
• Basic Link Data
• Link Control

Exchange
Sequence
Sequence
Sequence
Frame
Frame
Frame
Frame
Frame
Frame
11
FC-2 Transport Functions

• Flow Control
• Buffer-to-Buffer Credit
• Link Level
• End-to-End Credit
• Transport Level
• ULP Level
• Communication Models
• Full Duplex
• Half Duplex

12
FC-2 Transport Functions (cont)

• 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

13
FC-2 Transport Functions (cont)

• 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

14
FC-2 Transport Functions (cont)

• 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

15
FC-2 Transport Functions (cont)

• Block Management
• Data Reassembly
• Link Services
• Basic Link Services
• ABTS
• Extended Link Services
• Login, Process Login, Discovery, ...

16
FC Protocol for SCSI

• 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

17
FC Protocol for SCSI (cont)
ARB
FCP_CMND
FCP_XFER_RDY
Loop
SCSI ULP
SCSI ULP
FC Transport
FC Transport
NL_Port
NL_Port
FCP_DATA
FCP_RSP
OPN
CLS
Target
Initiator
Responder
Originator
SCSI Write Operation
18
FC Exception handling

• ULP Level
• Task and Loop Management
• Transport Level
• Sequence and Link Service Management
• Link Level
• Link Management

19
FC Committees

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

20
FC References

• 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 Protocolss The Users Guide to Serial SCSI
• Ancots What is Fibre Channel
• Ancots Fibre Channel Volume One The Basics