In-Depth Exploration of Serial Attached SCSI-2 (SAS-2.1)


The final SAS-2 standard was approved and became an industry standard early last year (Date: 2009/04/18, Rev: 16, Status: Published, Project: 1760-D). During the process of approving SAS-2 three additional standards were developed: 1) SAS Protocol Layer (SPL) which defines all SAS protocol layers from the Application layer to the Phy layer, 2) SAS-2.1 which defines the hardware used to connect devices both internally and externally, and finally 3) the SAS-3 standard which will define 12Gb SAS. When evaluating in-depth training it is important to consider that the materials and instructors are up to date on the most recent and latest technology. The documentation that you will receive when attending this course was completed in May 2010 and reflects the most recent draft versions of the standards. Our course developer and instructor frequently attends the T10 meetings.

This class examines and explores in detail the operation of SAS at all architectural levels. It takes you on a journey from the beginnings of SAS, through the detailed technical aspects of the architecture, and into the future of the technology. You will learn how SAS utilizes SCSI commands, which SCSI commands have changed, and what has changed in those commands. If you are an implementer, this provides important information that will assist you in the design, development and testing of SAS-based storage solutions. In addition, the Management Application layer is covered so that you will be able to design and implement your own management application client (MAC) in your host or self-configuring expander and your management device server (MDS) in a managed device.

In addition to learning how each layer of the SAS architecture works, you will learn about the latest in HD connector technology, how optical can be implemented, how zoning works and its impact on the configuration, how a topology with self-configuring expanders discovers and configures a SAS domain, and how to read analyzer traces.

You will also learn essential information about the operation of each of the different SAS protocols (SSP, STP, SMP), the format and structure of each of the SAS information units, Out-of-Band (OOB) signaling, resets, speed negotiation, multiplexing, how devices are interconnected in typical configurations, electrical design considerations like pre-emphasis and equalization, and the different cabling alternatives including untrained passive, trained passive and trained active cabling.

This seminar is designed for the developer and engineer; the person who has to design, develop, architect, program, test, support, or troubleshoot SAS configurations or products.

Course Outline

Introduction to SAS
What is Serial Attached SCSI?
Why Serial Attached SCSI?
Evolution of SAS Standards
SAS Roadmap
The SAS and SCSI Architectures
SAS Expander Devices & Ports
Logical links and multiplexing
SAS Names and Addresses
SAS Port & PHY Identifiers
SAS Structure and Protocol Layers
SAS Connections and Protocols
Serial SCSI Protocol (SSP)
Serial Management Protocol (SMP)
SATA Tunneled Protocol (STP)
SAS Configurations
Simple Internal Configuration
Wide Port Configurations
External JBOD Configuration
Daisy Chaining Enclosures
RAID Enclosure
 o Expander Routing Methods
 o Expander Functions
SAS Service Delivery Subsystem
SAS Physical Links
8b10b Encoding
Dwords and Primitives
Frame Transmission
Out-of-Band Signaling (OOB)
Speed Negotiation
SAS & SATA Resets
Device Identification
Pathways & Connections
 o Wide Ports and Multiple Connections
 o Partial Pathway
 o Blocked Partial Pathways and Deadlock
Zoning basics
SAS and SCSI Standards
SCSI Architecture Model
SCSI Initiator/Target/Logical Unit Model
Device Server & Task Manager
Task Set (Queue) & SCSI Nexus
SCSI Command Descriptor Block (CDB)
Task Attribute (Queue Type)
Autosense Request
 o SCSI Status & Sense Data
Task Management Functions
SCSI Application Items Affected By SAS
Mode pages
 o Disconnect-Reconnect
 o Protocol-Specific Logical Unit
 o Protocol-Specific Port
 o PHY Control And Discover
 o Shared Port Control
 o Enhanced PHY Control
Protocol-Specific Log page
Protocol-Specific diagnostic page
SSP Transport Layer
SCSI Transport Protocol Services
SSP Information Units
SSP Frame Format
SSP Link Layer
SSP Frame Characteristics
SSP Flow Control & Frame Acknowledgement
Closing an SSP Connection
DONE Primitives
SSP Frame or Protocol Error Handling
SCSI Application Layer Error Handling
SSP Transport Layer Handling
 o With and without retries
Serial Management Protocol (SMP)
SMP Overview
Management Components
 o Management application client
 o Management device server
 o SMP Initiator & Target
 o Managed Elements
SMP Link Layer Characteristics
SMP frame format
SMP Functions
SMP function usage
Function Results
Discovery functions
Discovery and Configuration Process
Discovery process overview
 o Starting the discover process (Broadcast (Change) handling)
 o Discover process traversal
 o Discovery process completion
 o Configuration sub-process
 o Allowed topologies
Discovery process
 o PHY information tables
 o Configuring Route tables
 o PHY-based ERT
 o Expander-based ERT
 o Self-configuring expanders


STP Transport and Link Layers
SATA Primitives & Frame Characteristics
SATA Flow Control
STP Connections
STP Affiliations
SATA Port Multiplier & Port Selector
Port Layer
Primitives, Notations & Characteristics
Single, Repeated, Triple and Extended Primitive Sequence
Primitive tables & descriptions
Clock Skew and Scrambling
ALIGN/NOTIFY Insertion & Elasticity Buffer
Idle Physical Links
Scrambling & Cyclic Redundancy Check (CRC)
Address Frames
IDENTIFY Address Frame
OPEN Address Frame
Identification and Hard Reset
SAS Hard Reset Sequence
SAS Initiator & Expander Device Rules
Connection Setup
Arbitration Wait Time (AWT)
Open Timeout Timer
Arbitration in Progress (AIP)
Closing a Connection (CLOSE)
Expander structure, ports and PHYs
ECM: Expander Connection Manager
ECR: Expander Connection Router
BPP: Broadcast Propagation Processor
SAS to SATA Bridges
Self-configuring expanders
Expander Addressing
Expander Routing
Zone Groups & Zone Permission Table
Zoning Expander Route Table
Expander Zoning Enforcement
Zoning PHY Information
Zoning Configuration
 o Lock, Load, Activate, & Unlock Phases
Encoding and serialization
SAS and SATA Byte Ordering
Encoding & 8b10b Description
Why Encode the Data?
Running Disparity
Data and Special Characters
8b10b Bit and Byte Notation
8b10b Special Character Encoding
Comma Pattern
8b10b Error Detection
 o Code Violation Errors
 o Disparity Errors
Out-of-Band (OOB) Signaling
OOB Signal Timing Requirements
Out-of-Band Signal Detection
Resets & Speed Negotiation
PHY Reset Sequences Overview
SAS Speed Negotiation
 o SNW-1, SNW-2 and Final-SNW
 o SNW-3 PHY Capability Bits
Hot Plug Detection
SATA PHY Speed Negotiation
SATA Speed Negotiation Timings
Rate Matching and Multiplexing
Cables and Connectors
Connectors & Connector categories
SAS/SATA drive connectors
Internal SAS cabling
 o Mini SAS 4i connectors
 o Mini SAS HD 4i & 8i
External SAS connectors
 o SAS-2 & SAS-1 external cabling and connectors
 o Mini SAS keying characteristics
 o Mini SAS HD external cabling
 o Mini SAS HD 4x, 8x, & 16x cable plug connector
SAS Advanced connectivity roadmap
Managed interconnects
Hot-Plug Considerations
SAS Icons
Transmitters and Receivers
SAS Physical Link
Differential Signaling
The Eye Diagram or Mask
Cable and Connector Losses
Transmitter Pre-Emphasis
Receiver Equalization
SAS Extended Distance Considerations

To view/download a PDF version of the
Table of Contents of the document for this
course, click the link below:
 SAS2.1 Table of Contents

Who Should Attend: This in-depth technical seminar is targeted towards hardware and software engineers involved in the design, development, integration, deployment, test, and maintenance of Serial Attached SCSI storage devices, storage subsystems and servers.
Prerequisites: The attendee should have previous experience or training with the SCSI architecture and command behavior. While this course has provides an overview of SCSI operation, having a prior understanding SCSI will make the course easier. Due to the similarities between the interfaces, a prior understanding of Fibre Channel will greatly assist you in understanding SAS.
Course Length:

4 days (recommended) or 3 days