Relaying frames in a large layer 2 network fabric
A network fabric includes interconnected network nodes, each having access to a database containing predetermined paths from each network node to each other network node in the network fabric. Each network node determines, in response to an incoming frame, whether the frame is a fabric protocol data unit (PDU) having a header containing path attributes including a destination node address. If the frame is a fabric PDU, the node selects a first path to the destination node from the database, and forwards the fabric PDU to a next hop in accordance with the selected path. If the frame is not a fabric PDU, the node selects a second path through the network fabric to the destination node from the database, adds the header with the path attributes to the frame to produce the fabric PDU, and forwards the fabric PDU to the next hop in accordance with the second path.
1. A network fabric, comprising:
a plurality of interconnected network nodes, each network node having access to a database containing predetermined paths from each network node in the network fabric to each other network node in the network fabric, each network node having a Layer 2 switching fabric and a processor configured to determine, in response to an incoming frame, whether the frame is a fabric protocol data unit (PDU) having a header with path attributes that include an address of a destination network node in the network fabric, and wherein,
if the frame is a fabric PDU, the processor is configured to select a first path to the destination network node from a database of predetermined paths, and to direct the switching fabric to forward the fabric PDU to a next hop in accordance with the selected first path,
otherwise, if the frame is not a fabric PDU, the processor is configured to select a second path through the network fabric to the destination network node from the database of predetermined paths, to add the header with the path attributes to the frame to produce the fabric PDU, and to direct the switching fabric to forward the fabric PDU to the next hop in accordance with the selected second path.
2. The network fabric of claim 1 , further comprising logic configured to generate the database of predetermined paths.
3. The network fabric of claim 2 , wherein each network node executes the logic to generate the database of predetermined paths.
4. The network fabric of claim 2 , further comprising a central control entity that executes the logic to generate the database of predetermined paths.
5. The network fabric of claim 1 , wherein the path attributes in the header of the frame produces a tunnel through the network fabric from a source network node to the destination network node.
6. The network fabric of claim 1 , further comprising an end system coupled to one of the network nodes, wherein the end system adds the header with the path attributes to the frame to produce the fabric PDU.
7. The network fabric of claim 1 , wherein the first and second paths diverge from each other at one or more communication links between a source network node and the destination network node.
8. The network fabric of claim 1 , wherein the processor is further configured to convert the frame into multiple fabric PDUs if the frame is a multicast frame.
9. The network fabric of claim 1 , wherein the network nodes are interconnected in a full mesh configuration.
10. The network fabric of claim 1 , wherein the processor of the destination network node is configured to remove the header with the path attributes from the fabric PDU.
11. The network fabric of claim 1 , further comprising an end system coupled to the destination network node, and wherein the processor of the destination network node is configured to direct the switching fabric of the destination network node to forward the fabric PDU to the end system, and the end system is configured to remove the header with the path attributes from the fabric PDU to restore the frame.
12. A network node, comprising:
a Layer 2 switching fabric receiving an incoming frame;
memory storing program code for processing the incoming frame; and
a processor, in response to executing the program code stored in the memory, determining whether the frame is a fabric protocol data unit (PDU) having a header containing path attributes that include an address of a destination network node, wherein,
if the frame is a fabric PDU, the processor is configured to select a first path to the destination network node from a database of predetermined paths, and to direct the switching fabric to forward the fabric PDU to a next hop in accordance with the selected first path,
otherwise, if the frame is not a fabric PDU, the processor is configured to select a second path through the network fabric to the destination network node from the database of predetermined paths, to add the header with the path attributes to the frame to produce the fabric PDU, and to direct the switching fabric to forward the fabric PDU to the next hop in accordance with the selected second path.
13. The network node of claim 12 , wherein the processor, in response to executing the program code stored in memory, generates and maintains the database of predetermined paths.
14. The network node of claim 12 , wherein the processor, in response to executing the program code stored in memory, converts the incoming frame into multiple fabric PDUs if the incoming frame is a multicast frame.
15. The network node of claim 12 , wherein the processor, in response to executing the program code stored in memory, removes the header with the path attributes from the fabric PDU to restore the frame and forwards the frame to a destination end system coupled to the network node.