ISO/IEC 14776-263:2018 PDF

Overview

ISO/IEC 14776-263:2018 - Information technology - Small Computer System Interface (SCSI) - Part 263: SAS Protocol Layer - 3 (SPL-3) - defines the rules and behaviour for exchanging SCSI information over a serial interconnect (Serial Attached SCSI, SAS). As part of the SCSI family of standards, SPL-3 specifies architecture, state machines, naming/identifier formats and protocol procedures that ensure reliable, interoperable communication between SAS devices, controllers and expanders.

Key topics and technical requirements

The standard covers technical topics and implementation requirements including:

• Architecture and layering
  • Definition of physical links (phys), logical links, ports (narrow/wide), domains and service delivery subsystems.
• Link and connection management
  • Connection lifecycle, persistent connections, advancing credit and data transmit/receive state machines.
• Device and expander models
  • Expander device topology, expander interfaces and internal components (routing, connection manager/router and broadcast handling).
• Discovery and configuration
  • Discover process, configuration subprocess, route table handling and topology constraints for auto-configuration and path discovery.
• Naming and identifiers
  • SAS addresses, NAA formats, port and phy identifiers, hashed addresses and device naming conventions for unique identification.
• Events and fault handling
  • Reset sequences (soft/hard reset), I_T nexus loss, power loss handling and event-related behaviours.
• Routing and broadcast mechanics
  • Expander routing attributes, route tables, broadcast propagation and routing restrictions.
• State machines and UML conventions
  • Formal state machine definitions for transmit/receive paths, timers, counters and message semantics.

These areas define mandatory protocol behavior that implementers must follow to achieve interoperability across SAS devices.

Applications

ISO/IEC 14776-263:2018 is applied where robust, high-performance serial SCSI transport is required:

• Designing and implementing SAS host bus adapters (HBAs), RAID controllers and storage controllers.
• Developing SAS expanders, enclosures and backplanes for storage arrays.
• Firmware and device driver development for enterprise storage systems, servers and SAN/NAS appliances.
• Interoperability testing, certification, conformance testing and test-lab validation of SAS devices.
• System integration involving SAS–SATA bridging, multipath routing and enterprise data center storage architectures.

Who should use this standard

• Storage hardware engineers and firmware developers
• System architects and integrators in enterprise storage
• Test laboratories and QA teams performing protocol conformance
• Product managers and technical leads specifying SAS implementations

Related standards

• Other parts of the ISO/IEC 14776 SCSI family that define alternate transport protocols and higher-level command sets for SCSI over different interconnects.

Keywords: ISO/IEC 14776-263:2018, SAS Protocol Layer 3, SPL-3, Serial Attached SCSI, SCSI standard, expander, SAS address, persistent connections, discover process.