Method for obtaining internet protocol header replacement mapping and network node

A packet data network gateway, comprising:

• at least one processor;
• and
• one or more memory coupled to the at least one processor and storing programming instructions for execution by the at least one processor, wherein the programming instructions, when executed, cause the packet data network gateway to:
• receive, from a user equipment (UE), a packet data network connection request that comprises a fixed part of an Internet protocol (IP) header;
• establish an IP header replacement mapping according to the fixed part of the IP header, wherein the IP header replacement mapping is a correspondence between the fixed part of the IP header and an index;
• and
• send a first data packet to the UE, wherein the fixed part of the IP header is substituted with the index in the first data packet.

A communication method, comprising:

• receiving, by a mobility management entity, a packet data network connection request from a user equipment (UE), wherein the packet data network connection request comprises a fixed part of an Internet protocol (IP) header;
• forwarding, by the mobility management entity, the packet data network connection request to a packet data network gateway;
• establishing, by the packet data network gateway, an IP header replacement mapping according to the fixed part of the IP header, wherein the IP header replacement mapping is a correspondence between the fixed part of the IP header and an index;
• and
• sending, by the packet data network gateway, a first data packet to the UE, wherein the fixed part of the IP header is substituted with the index in the first data packet.