1. A method in a near end network optimizer for supporting a delta compression technique for reducing network resource transmission size, wherein the near end network optimizer is coupled with a client device and coupled with a far end network optimizer, the method comprising: receiving, from the client device, a first request for a network resource; responsive to determining that a version of the network resource is stored in the near end network optimizer, transmitting a second request for the network resource to the far end network optimizer, the second request including a version identifier that identifies the version of the network resource stored in the near end network optimizer; receiving, from the far end network optimizer, a first response that includes a differences file that specifies a set of one or more differences between the version of the network resource stored in the near end network optimizer with a most current version of the network resource, wherein the first response does not include the entire network resource; applying the set of differences specified in the differences file to the version of the network resource stored in the near end network optimizer to generate an updated version of the network resource; and transmitting, to the client device, a second response that includes the updated version of the network resource.