Ultra reliable segment routing
SR-enabled network nodes capable of replicating and recombining data packets in a manner that enables reliable, low-latency communications. In an example embodiment, a replicator node transmits to a combinator node multiple copies of a payload over different respective network paths, with the SR headers of the corresponding packets each having a replication segment identifier or a respective SID stack that includes the replication segment identifier. The combinator node delivers/forwards to the corresponding application/destination only the first-to-arrive payload copy and discards any subsequent payload copies based on the replication segment identifier. Some embodiments may beneficially reduce latency and packet loss concurrently and consistently. For example, packet loss may be reduced due to the transmission of multiple copies of the same payload over multiple network paths. Effective latency may be reduced due to the selection of the first-to-arrive payload copy for delivery/forwarding.
1. An apparatus comprising a first node that comprises packet-processing circuitry and a memory, the first node being configured to transmit to a second node a packet set of two or more egress packets in response to an ingress packet, each of the two or more egress packets being temporarily stored in the memory for being transmitted via a different respective network path connecting the first and second nodes; and
wherein the packet-processing circuitry is configured to:
copy a payload of the ingress packet into each one of the two or more egress packets;
generate a replication segment identifier (RSID) identifying the packet set, wherein the RSID is generated based on the payload of the ingress packet; and
for each individual one of the two or more egress packets, generate a respective packet header having a respective segment-identifier (SID) stack, the respective SID stack including at least a first segment-routing (SR) SID and the RSID, the first SR SID identifying a segment for the individual one of the two or more egress packets for reaching the second node, the RSID identifying a replication segment for determining whether or not to delete the individual one of the two or more egress packets at the second node, wherein:
for each ingress packet, the two or more egress packets have the same RSID; and
the packet-processing circuitry is configured to adaptively change a length of the RSID in the egress packets for at least two different ingress packets.
2. The apparatus of claim 1 , wherein the packet-processing circuitry is configured to cause at least one of the respective SID stacks to include another respective SR SID being an identifier of another segment in the respective network path.
3. The apparatus of claim 1 , wherein the first node is configured to receive the ingress packet from a third node or from an application.
4. The apparatus of claim 1 , further comprising user equipment configured to implement the first node.
5. The apparatus of claim 1 , wherein the packet-processing circuitry is configured to apply a hash function to the payload of the ingress packet to generate the RSID.
6. The apparatus of claim 1 , wherein the packet-processing circuitry is configured to adaptively change the length of said RSIDs based on a feedback from the second node.
7. The apparatus of claim 1 , wherein the packet-processing circuitry comprises a value-derivation module and a value converter, the value derivation-module being configured to derive an output value from the payload of the ingress packet, the value converter being configured to generate the RSID by applying to the output value at least one of a truncation operation and a parsing operation.
8. The apparatus of claim 1 ,
wherein the packet-processing circuitry is configured to copy a first authentication-code value from the ingress packet into each one of the respective headers of the two or more egress packets; and
wherein the packet-processing circuitry comprises an authentication code computing circuit configured to compute respective second authentication-code values for the respective packet headers of the two or more egress packets.
9. The apparatus of claim 1 , wherein the first node further comprises a packet demultiplexer to connect the memory to the different respective network paths.