Subject: TimeStamp in registration replies

From: Terry L Anderson <[email-masked]>
Date: Mon, 15 Jan 2001 13:33:19 -0500

Christian -
I sent this some time ago but got no reponse.

Section 7.2.8 of H.248 states:
"The TimeStamp parameter shall be sent with a registration command and
its response."

There is a TimeStamp optional in ServiceChangeParm of both ASN.1 and
ABNF but it is NOT available in either ServiceChangeResParm (ASN.1) or
servChgReplyParm (ABNF) so I see no way to include it in the
registration response.

I do not see any correction to the text or to the ASN.1 or ABNF specs
for this in the Implementors' Guide.

I think that including TimeStamp in the reply is useful as it allows the
MG to know any time skew as well as the MGC knowing it, but it may be
difficult to change the ABNF and ASN.1 at this point.  If they cannot be
changed I think that the sentence should be corrected to say:
    "The TimeStamp parameter shall be sent with a registration command."

through the IG.

--
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Terry L Anderson              mailto:[email-masked]
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From: Christian Groves <[email-masked]>
Date: Tue, 16 Jan 2001 16:40:15 +1100

G'Day Terry,

It does seem something is amiss here. Although I'm not sure of the best
way to fix it. The first mention of timestamp in 7.2.8 specifies "It
(timestamp) can be used by the responder to determine how its notion of
time differs from that of its correspondent." Which is fine when it is
sent by one entity (MGC or MG) as the peer can adjust accordingly. But
if both the MGC and MG send it then who should adjust to what? I think
if both send it we need a little more procedural text to go with
ASN1/ABNF change.

The 2nd mention of timestamp in 7.2.8 the sentence you mention seems a
little bit out of place so I'm wondering if it is a left over.

I agree that something needs to be done but I'm not sure which
something. Other opinions?

I'll put a place holder for this in the implementors' guide additions.

Cheers, Christian