Method, apparatus, and system for qos within high performance fabrics

Abstract

Method, apparatus, and systems for implementing Quality of Service (QoS) within high performance fabrics. A multi-level QoS scheme is implemented including virtual fabrics, Traffic Classes, Service Levels (SLs), Service Channels (SCs) and Virtual Lanes (VLs). SLs are implemented for Layer 4 (Transport Layer) end-to-end transfer of fabric packets, while SCs are used to differentiate fabric packets at the Link Layer. Fabric packets are divided into flits, with fabric packet data transmitted via fabric links as flits streams. Fabric switch input ports and device receive ports detect SC IDs for received fabric packets and implement SC-to-VL mappings to determine VL buffers to buffer fabric packet flits in. An SL may have multiple SCs, and SC-to-SC mapping may be implemented to change the SC for a fabric packet as it is forwarded through the fabric, while maintaining its SL. A Traffic Class may include multiple SLs, enabling request and response traffic for an application to employ separate SLs.

What is claimed is: 
     
         1 . A method comprising:
 implementing a plurality of Service Levels (SLs) for transferring fabric packets between fabric endpoints in a fabric comprising a plurality of fabric links coupled between fabric ports of a plurality of fabric devices;   assigning one or more Service Channels (SCs) to each Service Level;   at each of at least a portion of the fabric ports, assigning SCs to Virtual Lanes (VLs); and   dividing each fabric packet into a plurality of flits, and effecting transfer of fabric packets between fabric endpoints by transferring the flits for the fabric packets over the fabric links using SCs;   wherein the VL used to buffer flits for a given fabric packet to be transmitted across a given fabric link is determined based on an SC implemented for transferring the flits across the fabric link.