Routing in an communications network having a distributed S/PGW architecture

A method by a Packet Processing Unit (PPU) in a communications network to allow a plurality of PPUs in the communications network to route data packets, the method comprising:

• receiving a data packet addressed to a destination Internet Protocol (IP) address and an access point name (APN) associated with an IP session of a user entity (UE), wherein the plurality of PPUs in the communications network collectively maintain a distributed hash table (DHT) storing a distributed routing table (DRT), wherein the DRT includes a DRT entry that maps a key to a value, wherein the key of the DRT entry is based on both the destination IP address and the APN associated with the IP session of the UE, wherein the value of the DRT entry represents both an IP address of one of the plurality of PPUs currently serving the IP session of the UE and an IP session identifier that identifies, to that PPU currently serving the IP session of the UE, the IP session of the UE;
• determining, based on the destination IP address and the APN associated with the IP session of the UE, the key for the DRT entry;
• looking up, using a DHT algorithm and based on the determined key, which of the plurality of PPUs is responsible for storing the DRT entry in the DHT;
• accessing, from the PPU responsible for storing the DRT entry in the DHT, the value of the DRT entry;
• and
• tunneling the data packet to the IP address of the PPU currently serving the IP session of the UE using the IP session identifier based on the value.

A network device to function as a Packet Processing Unit (PPU) in a communications network to allow a plurality of PPUs in the communications network to route data packets, the network device comprising:

• a set of one or more processors;
• and
• a memory containing instructions, which when executed by the set of one or more processors, cause the network device to:
• receive a data packet addressed to a destination Internet Protocol (IP) address and an access point name (APN) associated with an IP session of a user entity (UE), wherein the plurality of PPUs in the communication networks are to collectively maintain a distributed hash table (DHT) storing a distributed routing table (DRT), wherein the DRT includes a DRT entry that maps a key to a value, wherein the key of the DRT entry is based on both the destination IP address and the APN associated with the IP session of the UE, wherein the value of the DRT entry represents both an IP address of one of the plurality of PPUs currently serving the IP session of the UE and an IP session identifier that identifies, to that PPU currently serving the IP session of the UE, the IP session of the UE;
• determine, based on the destination IP address and the APN associated with the IP session of the UE, the key for the DRT entry,
• look up, using a DHT algorithm and based on the determined key, which of the plurality of PPUs is responsible for storing the DRT entry in the DHT,
• access, from the PPU responsible for storing the DRT entry in the DHT, the value of the DRT entry, and
• tunnel the data packet to the IP address of the PPU currently serving the IP session of the UE using the IP session identifier based on the value.