2. The method of claim 1 , wherein the initial compression dictionary comprises blocks of data that have already been compressed.
2. The method of claim 1 , wherein the initial compression dictionary comprises blocks of data that have already been compressed. 3. The method of claim 2 , implemented in a compressing device having a communication session with a remote communicating device, and wherein the secondary dictionary comprises data already exchanged between the compressing device and the remote communicating device.