Patent ID: 7215667
Filing Date: 2007-05-08
Classification: H04L

Abstract:
1. A method for communicating IPSec tunnel packets with compressed inner headers, a tunnel header, an IPSec header, an encapsulated portion, and an authentication code, the method comprising: storing an inner IP header and an inner protocol header from an initial IPSec tunnel packet in a context sub-table at a destination tunnel device; for a subsequent IPSec tunnel packet, generating at the source tunnel device a compressed inner header from the inner protocol header of the subsequent IPSec tunnel packet; performing a operation on at least one of the compressed inner header, a payload field and a padding field of the subsequent IPSec tunnel packet to generate the encapsulated portion; replacing at least one of the inner IP header, the inner protocol header, the payload field and the padding field of the subsequent IPSec tunnel packet with the encapsulated portion to generate an IPSec tunnel packet with compressed inner headers; at the destination tunnel device, identifying a security association database entry for the tunnel using a security policy index number in the IPSec header; at the destination tunnel device, decrypting the encapsulated portion to determine at least one of the compressed inner protocol header and the padding field, the padding field including a context sub-table identifier to identifies a context sub-table associated with the security association database entry; at the destination tunnel device, retrieving at least one of the inner IP header and the inner protocol header for the subsequent IPSec tunnel packet from the context sub-table; and recreating the subsequent IPSec tunnel packet using the inner IP header and inner protocol header retrieved from the context sub-table.