Differences between Recommendation X.224 and ISO 8073 (1986)
Recommendation X.224 and ISO 8073 (1986) are technically aligned except for
the differences listed below:
II.1 Defect reports
In collaboration, ISO and CCITT have agreed to corrections resulting from
defect reports. Recommendation X.224 includes corrections from Reports 4, 6, 7, 9,
11, 16, 17, 20, 22, 23, 27, 28, 29 (items 1-7), 32, 33, 34, 35, 36, 38, 39 (item 2),
40, 41, 42, 43, 45, 52, 56, 59, 61, 65, 67, 69, 71, 72, 73, 74 (items 1-3 and 5-10),
77 (item 2), 80, 81, 85, 89, 91, 93, 94, 103 and 106. An update of ISO 8073 had not
yet been published by March 1988.
Note - Defect Reports 1, 2, 3, 5, 10, 12, 13, 14, 15, 18, 19, 21, 25, 26, 51, 57,
58, 60, 66, 74 (items 4, 11 and 12), 82, 84, 87, 88, 90, 92, 95, and 107 do not
apply to Recommendation X.224 and in addition Defect Reports 8, 24, 29 (item 2), 39
(item 1), 46, 48, 55, 62, 64 (item 2), 68, 76 (item 2), 77 (item 1), 79, 86, 97, 99
and 104 have been rejected. No further changes to Recommendation X.224 will be made
as a result of these defect reports.
II.2 Conformance
Recommendation X.224, in section 14, requires all systems to implement
class 0. ISO 8073, in Clause 14, requires all systems to implement either
class 0 or class 2.
II.3 Class negotiation
An additional restriction regarding the classes of transport protocol that
are proposed in a CRTPDU is defined in item (a) in sub-section 14.4 of
Recommendation X.224. No such restriction is contained in ISO 8073.
II.4 Precedence
ISO 8073, in its Annex A ( ), includes the statement: "In the event of a
discrepancy between the description in these tables and that contained in the text,
the text takes precedence." Recommendation X.224 does not contain this statement.
II.5 Assignment to network connections
In section 6.1.3 of Recommendation X.224 it is stated that the responder to
the transport connect request becomes aware of the assignment when it receives
particular TPDUs. In Clause 6.1.3 of ISO 8073 it is the non-owner of the network
connection that becomes aware of the assignment upon receipt of these same TPDUs.
II.6 Transport protocol identification
The material contained in Annex B of Recommendation X.224 is not present in
ISO 8073.
II.7 Checksum algorithms
The material contained in Appendix I to Recommendation X.224 is contained in
Annex B to ISO 8073.
II.8 Differences between Recommendation X.224 and ISO 8073
The material in this appendix is not present in ISO 8073.
