Encoding source routes using MPLS sub-labels
Generally disclosed herein is an approach for modifying use of segment routing multiprotocol label switching (SR-MPLS) allowing an arbitrary MPLS control plane and traditional MPLS data plane to utilize a single MPLS label to represent two or more edges in a path. MPLS labels may be divided into smaller sub-labels, which together uniquely represent a pair of edges along a route. In one example, a single MPLS label may be divided into two sub-labels, the first sub-label representing a first edge, and the second sub-label representing a second edge. In this regard, longer source routes may be supported in a packet header in network designs that implement strict source routing.
1 . A method for encoding source routes using multiprotocol label switching (MPLS) sub-labels, the method comprising:
dividing, by one or more processors, a memory segment of a packet corresponding to an MPLS label in an MPLS header into at least a first sub-segment and a second sub-segment;
storing, by the one or more processors, first information for a first edge of a route in the first sub-segment and second information for a second edge of the route in the second sub-segment, padding the second sub-segment with zeros when only a subset of the second sub-segment is required.
2 . The method of 1 , wherein the MPLS label in the MPLS header is divided into N numbers of sub-segments.
3 . The method of 2 , wherein the N numbers of sub-segments store information of N numbers of edges in the route.
4 . The method of 1 , further comprising:
receiving, by the one or more processors, the packet including the MPLS header; and
transmitting, by the one or more processors, the packet from a source node to a destination node based on a combination of the information stored in the first sub-segment and the information stored in the second sub-segment.
5 . The method of 1 , further comprising:
assigning an identifier for each of one or more edges that is unique from any other edge originating from a node within a N degree of neighbors.
6 . The method of 1 , further comprising:
distributing a combination of the first information stored in the first sub-segment and the second information stored in the second sub-segment using an intermediate system to intermediate system (IS-IS) protocol.
7 . The method of 1 , wherein the first information and the second information is programmed using an application programming interface (API) with a remote call procedure call (RPC)-based protocol.
8 . The method of 1 , wherein each of the first sub-segment and the second sub-segment store 10 bits of information.
9 . The method of 8 , wherein each 10-bit sub-labels may encode a link ID as distributed by a link-state protocol.
10 . A system comprising:
one or more processors;
memory in communication with the one or more processors, wherein the memory contains instructions configured to cause the one or more processors to:
divide a memory segment of a packet corresponding to an MPLS label in an MPLS header into at least a first sub-segment and a second sub-segment; and
store first information for a first edge of a route in the first sub-segment and second information for a second edge of the route in the second sub-segment, wherein the instructions are further configured to cause the one or more processors to pad the second sub-segment with zeros when only a subset of the second sub-segment is required.
11 . The system of 10 , wherein the MPLS label in the MPLS header is divided into N numbers of sub-segments.
12 . The system of 11 , wherein the N numbers of sub-segments store information of N numbers of edges in the route.
13 . The system of 10 , wherein the instructions are further configured to cause the one or more processors to:
receive the packet including the MPLS header; and
transmit the packet from a source node to a destination node based on a combination of the information stored in the first sub-segment and the information stored in the second sub-segment.
14 . The system of 10 , wherein the instructions are further configured to cause the one or more processors to assign an identifier for each of one or more edges that is unique from any other edge originating from a node within a N degree of neighbors.
15 . The system of 10 , wherein the instructions are further configured to cause the one or more processors to distribute the combination of the first information stored in the first sub-segment and the second information stored in the second sub-segment using an intermediate system to intermediate system (IS-IS) protocol.
16 . The system of 10 , wherein the first information and the second information is programmed using an application programming interface (API) with a remote call procedure call (RPC) based protocol.
17 . The system of 10 , wherein each of the first sub-segment and the second sub-segment store 10 bits of information.
18 . The system of 17 , wherein each 10-bit sub-labels may encode a link ID as distributed by a link-state protocol.