DDS-XTypes 1.4 RTF Avatar
  1. OMG Issue

DDSXTY14 — Inconsistent Definitions of RTPS Encapsulation

  • Key: DDSXTY14-20
  • Status: open  
  • Source: Object Computing, Inc. - OCI ( Frederick Hornsey)
  • Summary:

    There are inconsistencies in the two definitions of the RTPS Encapsulation Header I've found so far. The major issue is that the values for the encoding identifiers are different between 7.4.3.4 and 7.6.3.1.2 for non-XCDR1 encodings. These are the big-endian values compared:

    Type 7.4.3.4 7.6.3.1.2
    Plain XCDR2 0x00, 0x10 0x00, 0x06
    Parameter List XCDR2 0x00, 0x12 0x00, 0x0a
    Delimited XCDR2 0x00, 0x14 0x00, 0x08
    XML 0x01, 0x00 0x00, 0x04

    The other issue is that while 7.6.3.1.2 describes the two options bytes of the encapsulation header that follow the encoding identifier and extends it for padding info, 7.4.3. is lacking in details as far as I can see. The serialization rules has them in 7.4.3.5.3 as `OPTIONS`, but doesn't define it in any of the tables before the rules like all the other symbols are. It does mention encapsulation in 7.4.3.5, but doesn't mention anything about extending the options bytes.

  • Reported: DDS-XTypes 1.3b1 — Thu, 4 Jun 2020 17:51 GMT
  • Updated: Sat, 2 Oct 2021 00:10 GMT