KB139636 - X400: Abbreviations for CCITT Recommendation X.224

Article ID: 139636

Article Last Modified on 10/30/2006

Microsoft Mail Gateway to X.400 3.0
Microsoft Mail Gateway to X.400 3.2

This article was previously published under Q139636

SUMMARY

This article lists some of the acronyms that are seen when you view the X400MMDD.LOG file, where mmdd represents the month (mm) and the day (dd) the log was written when debug (-LD) was enabled.

MORE INFORMATION

Data Units

   TPDU           Transport Protocol Data Unit
   TSDU           Transport Service Data Unit
   NSDU           Network Service Data Unit

Types of Transport Protocol Data Unit

   CR TPDU        Connection Request TPDU
   CC TPDU        Connection Confirm TPDU
   DR TPDU        Disconnect Request TPDU
   DC TPDU        Disconnect Confirm TPDU
   DT TPDU        Data TPDU
   ED TPDU        Expedited Data TPDU
   AK TPDU        Data Acknowledge TPDU
   EA TPDU        Expedited Acknowledge TPDU
   RJ TPDU        Reject TPDU
   ER TPDU        Error TPDU

TPDU fields

   LI             Length Indicator (field)
   CDT            Credit (field)
   TSAP-ID        Transport Service Access Point Identifier (field)
   DST-REF        Destination Reference (field)
   SRC-REF        Source Reference (field)
   EOT            End of TSDU mark
   TPDU-NR        DT TPDU number (field)
   ED-TPDU-NR     ED TPDU number (field)
   YR-TU-NR       Sequence number response (field)
   YR-EDTU-NR     ED TPDU number response (field)

Time and associated variables

   T1             Local retransmission time
   N              The maximum number of retransmission's
   L              Time bound on reference and sequence numbers
   I              Inactivity time
   W              Window time
   TTR            Time to try reassignment/resynchronization
   TWR            Time to wait for reassignment/resynchronization
   TS1            Supervisory timer 1
   TS2            Supervisory timer 2
   MLR            NSDU lifetime local-to-remote
   MRL            NSDU lifetime remote-to-local
   ELR            Expected maximum transit delay local-to-remote
   ERL            Expected maximum transit delay remote-to-local
   R              Persistence time
   AL             Local acknowledge time
   AR             Remote acknowledge time

Miscellaneous

   TS-user        Transport Service user
   TSAP           Transport Service Access Point
   NS-provider    Network Service Provider
   NSAP           Network Service Access Point
   QOS            Quality of service

The information above was extracted from The International Telegraph and Telephone Consultative Committee (CCITT), Recommendation X.224, Section 4, page 43. Please refer to Recommendation X.224 for a more in-depth definition and description.

For additional information on the X400MMDD.LOG, please see the following article in the Microsoft Knowledge Base:

86988 X400: How MTAs Initiate and Communicate

Additional query words: 3.00 3.20

Keywords: KB139636