A data processing system is described that employs data packets which include at least static and dynamic fields, the static fields containing information that often remains constant during a multi-packet communication interval and the dynamic fields containing information that changes for each packet. Many packets also include a user-data fields. A compression method is described which comprises: reformatting each data packet by associating its static fields with a first packet region and its dynamic fields with a second packet region. The process then assembles a static table that includes static information from at least an initial data packet's first packet region. It then identifies static field information in a subsequent data packet's first packet region that is common to the information in the static table. Such common information is encoded so as to reduce its data length. The common static information is then replaced in the modified data packet with the encoded common static information and the modified data packet is then transmitted. A similar action occurs with respect to user-data information. A single dictionary table is created for all packet headers, while separate dictionary tables are created for each user-data portion of a packet-type experienced in the communication network thereby enabling better compression.