Pete,
Just a minor adjustment. H.450.1 specifies the use of call-independent signaling.
Bob
-------------------------------------- Robert Callaghan Siemens Business Communication Systems Email: Robert.Callaghan@Siemenscom.com Tel: +1.561.997.3756 FAX: +1.561.997.3403
-----Original Message----- From: Pete Cordell [SMTP:pete.cordell@BT-SYS.BT.CO.UK] Sent: Friday, February 20, 1998 8:44 AM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: User Information or Information in H.225.0
Glen,
On closer examination there seem to be a few errors in Table 4/H.225.0. The 6th paragraph of section 7.1/H.225.0 (white paper at least) says that the "The procedures of Q.931/Section 3.1 for circuit mode connection setup are followed." According to this section the messages "User Information" and "Congestion Control" do not apply. They are used in the call-independent signalling part that we are not using.
Also "Status Inquiry" is spelt "Status Enquiry" in Q.931 (not that I would know what is the right form!!!).
We need to go with option 1 of your suggestions. The Information message is what we need for overlap sending. The description part of 7.3.6 is correct for the "Information" message (including the reference to the table in Q.931).
If we can silently remove "Congestion Control" at the same time so much the better!!!!!
Regards,
Pete
Pete Cordell BT Labs E-Mail: pete.cordell@bt-sys.bt.co.uk Tel: +44 1473 646436 Fax: +44 1473 645499 =================================
From: Glen Freundlich[SMTP:ggf@LUCENT.COM] Sent: 19 February 1998 16:09 To: ITU-SG16@MAILBAG.INTEL.COM Subject: User Information or Information in H.225.0
In H.225.0 V1, section 7.3.6 describes the User Information message. The related ASN.1 definition is named UI-UUIE, but the table and caption (Table 9) describe the Q.931 Information message.
H.323 V2 describes the use of the Information message (for example, to support overlap sending), but H.225.0 V2 contains no section describing the Information message and no ASN.1 has been defined specifically for use with the Information message.
Possible fixes seem to be:
1 - rename section 7.3.6 from "User Information" to "Information" and add some text stating that the Information message is used to support overlap sending
2 - correct section 7.3.6 to align with the User Information message (correct the table, correct the reference to Q.931) and add a new section (and associated ASN.1) for the Information message
3 - other suggestions?
As backward compatibility is a concern, the best approach depends on existing implementations and the use of User Information or Information messages. So, a vendor that decides to implement might interpret this to be a User Information message with a different set of information elements (not as described in table 9/H225) or an Information message with the set of information elements as defined in table 9.
Please comment.
Regards, Glen Freundlich (editor H.225.0)
-- Glen Freundlich ggf@lucent.com Lucent Technologies office: +1 303 538 2899 11900 N. Pecos fax: +1 303 538 3907 Westminster, Colorado 80234 USA