Duplication of packets and their detection in X.25 communication protocols

ABSTRACT

In the context of X.25 communication protocols, this paper is concerned with the process of duplication of packets at the frame level, and with their detection at the packet level. With suitable constraints involving (i) the window sizes used at both the frame and packet levels to flow control, and (ii) the numbering scheme used to number User Data packets, it is possible to detect and discard all duplicate copies thereof. Further, it is argued that duplication of 'messages' by a particular layer be detected at the level where these messages are generated and interpreted. Deferring this detection to higher levels is unnecessary and more difficult.

REFERENCES

• 1: Robert, L. G., B. G. Wellser, "Computer Network Development to Achieve Resource Sharing", AFIPS Proc., SJCC, 1970.
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• 3: CCITT, "Public Data Networks", Recommendations of the Sixth Plenary Assembly, Orange Book, vol. VIII 2, Intern. Telecom. Union, Geneva, pp. 70-108.
• 4: CCITT, "Final Report on the work of Study Group VII during the period 1977-1980, pt. III.2: Recommendation X.25", Doc. AP VII, No. 7-E, Geneva, 1980.
• 5: Simon S. Lam, Data Link Control Protocols, University of Texas at Austin, Austin, TX, 1980
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INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Packet-switching networks

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.0 General

          Nouns: X.25
      C.2.2 Network Protocols

General Terms:
Design, Verification