Multi-path id routing in a pcie express fabric environment
AssigneePLX Technology, Inc.
InventorsJack REGULA, Jeffrey M. DODSON, Nagarajan SUBRAMANIYAN
Life of this patent
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Abstract
PCIe is a point-to-point protocol. A PCIe switch fabric has multi-path routing supported by adding an ID routing prefix to a packet entering the switch fabric. The routing is converted within the switch fabric from address routing to ID routing, where the ID is within a Global Space of the switch fabric. Rules are provided to select optimum routes for packets within the switch fabric, including rules for ordered traffic, unordered traffic, and for utilizing congestion feedback. In one implementation a destination lookup table is used to define the ID routing prefix for an incoming packet. The ID routing prefix may be removed at a destination host port of the switch fabric.
Claims32
A method of operating a multi-path switch fabric having a point-to-point network protocol, the method comprising:
- for a packet having a load/store protocol address entering an ingress port of the switch fabric, adding an ID routing prefix to the packet defining a destination ID in a global space of the switch fabric;
- and
- routing the packet to a destination in the switch fabric based on the ID routing prefix.
A method of ID routing in a switch fabric, comprising:
- performing a look up of destination route choices in a destination lookup table, using the destination ID in an ID routing prefix prepended to the packet or in the packet itself, if the packet doesn't have a prefix.
The method of 8 where the lookup is indexed by either Destination Domain or by Destination BUS independently configurable at each ingress port.
The method of 9 where lookup using Destination Domain is prohibited if congestion feedback indicates that the route by domain choice would encounter congestion.
A method of operating a multi-path PCIe switch fabric, the method comprising:
- for a PCIe packet entering the switch fabric, converting the routing from address based routing to ID based routing by performing a table lookup to define an ID routing prefix defining a destination ID and adding the ID routing prefix to the packet, wherein the ID routing prefix defines an ID in a global space of the switch fabric.
The method of 16 where the lookup is indexed by either Destination Domain or by Destination BUS independently configurable at each ingress port.
The method of 24 where lookup using Destination Domain is prohibited if congestion feedback indicates that the route by domain choice would encounter congestion.
A system comprising:
- a switch fabric including at least one PCIe ExpressFabric™ switch and a management system;
- wherein a Global ID space is defined for the switch fabric in which each node and device function have a unique Global ID
- and wherein packets entering the switch that would be address routed in standard PCIe have an ID routing prefix added to route the packet within the switch fabric by Global ID.
Dependencies are inferred from the claim text.