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<P><FONT SIZE=2>Or something like "H.323 entities shall only process the first fastStart element it receives for a call".</FONT>
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<P><FONT SIZE=2>Thanks guys.</FONT>
</P>
<P><FONT SIZE=2>> -----Original Message-----</FONT>
<BR><FONT SIZE=2>> From: Sasha Ruditsky [<A HREF="mailto:sasha@RADVISION.COM">mailto:sasha@RADVISION.COM</A>]</FONT>
<BR><FONT SIZE=2>> Sent: Friday, May 18, 2001 12:16 PM</FONT>
<BR><FONT SIZE=2>> To: ITU-SG16@mailbag.cps.intel.com</FONT>
<BR><FONT SIZE=2>> Subject: Re: Switching to H.245</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Hi François</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Probably I'll try to state you question in more generic way.</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> We know that it is possible to perform OLC operations after fast start</FONT>
<BR><FONT SIZE=2>> completed</FONT>
<BR><FONT SIZE=2>> and before another Q.931 message (like ALERTING or CONNECT) </FONT>
<BR><FONT SIZE=2>> with fast start</FONT>
<BR><FONT SIZE=2>> is sent.</FONT>
<BR><FONT SIZE=2>> (the simplest probably is to close channel opened using fast start)</FONT>
<BR><FONT SIZE=2>> (3rd party pause and redirection is of course procedure of this kind)</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> What is the meaning of the fast start in such CONNECT message?</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> And here I agree with Chris that such fast start elements </FONT>
<BR><FONT SIZE=2>> should be ignored.</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> So probably the text that may solve this and should be added </FONT>
<BR><FONT SIZE=2>> should state</FONT>
<BR><FONT SIZE=2>> something like:</FONT>
<BR><FONT SIZE=2>> "H.323 entity shall process fast start elements only once </FONT>
<BR><FONT SIZE=2>> during the call."</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> BTW Probably the same statement should be done about </FONT>
<BR><FONT SIZE=2>> h245Address. I just</FONT>
<BR><FONT SIZE=2>> know one H.323 endpoint that established 3 H.245 connections </FONT>
<BR><FONT SIZE=2>> when got the</FONT>
<BR><FONT SIZE=2>> h245Address in CALL PROCEEDING, ALERTING and CONNECT.</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Sasha</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> -----Original Message-----</FONT>
<BR><FONT SIZE=2>> From: Chris Wayman Purvis [<A HREF="mailto:cwp@ISDN-COMMS.CO.UK">mailto:cwp@ISDN-COMMS.CO.UK</A>]</FONT>
<BR><FONT SIZE=2>> Sent: Friday, May 18, 2001 6:56 AM</FONT>
<BR><FONT SIZE=2>> To: ITU-SG16@mailbag.cps.INTEL.COM</FONT>
<BR><FONT SIZE=2>> Subject: Re: Switching to H.245</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Francois,</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Good catch! My suggestion would be to add some text saying </FONT>
<BR><FONT SIZE=2>> that anything</FONT>
<BR><FONT SIZE=2>> exchanged via H.245 overrides anything done by fastStart, even if the</FONT>
<BR><FONT SIZE=2>> fastStart happens to arrive later.</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Now what happens if there's a possible scenario someone can </FONT>
<BR><FONT SIZE=2>> devise where you</FONT>
<BR><FONT SIZE=2>> manage to get tunnelled and "separate connection" H.245 </FONT>
<BR><FONT SIZE=2>> contradicting each</FONT>
<BR><FONT SIZE=2>> other is a thornier problem - can anyone see that happening?</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Regards,</FONT>
<BR><FONT SIZE=2>> Chris</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Francois Audet wrote:</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> > Hum, interesting.</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > My follow up question is then:</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > * A sends SETUP to B with fast start with h245Address and</FONT>
<BR><FONT SIZE=2>> > tunnelling. ALERTING responds to FS, and the whole TCS and M/S</FONT>
<BR><FONT SIZE=2>> > process takes place. Then A wants to forward the call </FONT>
<BR><FONT SIZE=2>> (internally)</FONT>
<BR><FONT SIZE=2>> > before answer (i.e., in the ALERTING phase). It thus </FONT>
<BR><FONT SIZE=2>> sends TCS=0,</FONT>
<BR><FONT SIZE=2>> > TCS=full, OLCs and all that. Then B answers and sends </FONT>
<BR><FONT SIZE=2>> the CONNECT</FONT>
<BR><FONT SIZE=2>> > (with the same fastStart as the ALERTING as per earlier</FONT>
<BR><FONT SIZE=2>> > discussions we had ;^) Wouldn't the content of the fastStart</FONT>
<BR><FONT SIZE=2>> > contradict what the actual forwarded connections is </FONT>
<BR><FONT SIZE=2>> really? Would</FONT>
<BR><FONT SIZE=2>> > it be a problem?</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > Seems pretty tricky...</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > -----Original Message-----</FONT>
<BR><FONT SIZE=2>> > From: Paul Long [<A HREF="mailto:plong@IPDIALOG.COM">mailto:plong@IPDIALOG.COM</A>]</FONT>
<BR><FONT SIZE=2>> > Sent: Thursday, May 17, 2001 11:52 AM</FONT>
<BR><FONT SIZE=2>> > To: ITU-SG16@MAILBAG.INTEL.COM</FONT>
<BR><FONT SIZE=2>> > Subject: Re: Switching to H.245</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > Francois,</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > I realize how this could be confusing, but I don't </FONT>
<BR><FONT SIZE=2>> necessarily see a</FONT>
<BR><FONT SIZE=2>> > conflict since they all say, "may." For example, if I </FONT>
<BR><FONT SIZE=2>> say, "X may do</FONT>
<BR><FONT SIZE=2>> > A or B," and, "X may do B," that does not preclude "X may do A."</FONT>
<BR><FONT SIZE=2>> > Conversely, if I said "shall" instead of "may," I think </FONT>
<BR><FONT SIZE=2>> there would</FONT>
<BR><FONT SIZE=2>> > be real conflicts. I've worked on EPs that are very aggressive</FONT>
<BR><FONT SIZE=2>> > during call establishment. For example, Setup contains an</FONT>
<BR><FONT SIZE=2>> > h245Address and indicates support for Fast Connect and H.245</FONT>
<BR><FONT SIZE=2>> > Tunneling. Other than all the non-compliant EPs out </FONT>
<BR><FONT SIZE=2>> there, it worked</FONT>
<BR><FONT SIZE=2>> > just fine. The EPs also support third-party pause, but I don't</FONT>
<BR><FONT SIZE=2>> > remember ever testing that particular scenario. As long </FONT>
<BR><FONT SIZE=2>> as an EP is</FONT>
<BR><FONT SIZE=2>> > implemented correctly, I don't see anything in the </FONT>
<BR><FONT SIZE=2>> Recommendation</FONT>
<BR><FONT SIZE=2>> > that would prevent this from working.</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > Paul Long</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > ipDialog, Inc.</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > -----Original Message-----</FONT>
<BR><FONT SIZE=2>> > From: Mailing list for parties associated with </FONT>
<BR><FONT SIZE=2>> ITU-T Study Group</FONT>
<BR><FONT SIZE=2>> > 16 [<A HREF="mailto:ITU-SG16@mailbag.cps.INTEL.COM">mailto:ITU-SG16@mailbag.cps.INTEL.COM</A>]On Behalf </FONT>
<BR><FONT SIZE=2>> Of Francois</FONT>
<BR><FONT SIZE=2>> > Audet</FONT>
<BR><FONT SIZE=2>> > Sent: Thursday, May 17, 2001 1:07 PM</FONT>
<BR><FONT SIZE=2>> > To: ITU-SG16@mailbag.cps.INTEL.COM</FONT>
<BR><FONT SIZE=2>> > Subject: Switching to H.245</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > Guys,</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > H.323/8.1.7.2 says :</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > After establishment of a call using the Fast Connect</FONT>
<BR><FONT SIZE=2>> > procedure, either endpoint may determine that it is</FONT>
<BR><FONT SIZE=2>> > necessary to invoke call features that require </FONT>
<BR><FONT SIZE=2>> the use of</FONT>
<BR><FONT SIZE=2>> > H.245 procedures. Either endpoint may initiate </FONT>
<BR><FONT SIZE=2>> the use of</FONT>
<BR><FONT SIZE=2>> > H.245 procedures at any point during the call, using</FONT>
<BR><FONT SIZE=2>> > tunnelling as described in 8.2..1 (if </FONT>
<BR><FONT SIZE=2>> h245Tunnelling remains</FONT>
<BR><FONT SIZE=2>> > enabled) or a separate H.245 connection. The process for</FONT>
<BR><FONT SIZE=2>> > switching to a separate H.245 connection is described in</FONT>
<BR><FONT SIZE=2>> 8.2.3.</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > 8.2..3 says:</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > When H.245 encapsulation or Fast Connect is being used,</FONT>
<BR><FONT SIZE=2>> > either endpoint may choose to switch to using </FONT>
<BR><FONT SIZE=2>> the separate</FONT>
<BR><FONT SIZE=2>> > H.245 connection at any time.</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > There seem to be some contradiction in there: is it "after</FONT>
<BR><FONT SIZE=2>> > establishment" or "at any time"?</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > Do you have to wait for after CONNECT to establish </FONT>
<BR><FONT SIZE=2>> a separate</FONT>
<BR><FONT SIZE=2>> > H.245 channel or not?</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > The case I'm interested in would be to send SETUP with</FONT>
<BR><FONT SIZE=2>> > fastStart, then receive ALERTING with fastStart. </FONT>
<BR><FONT SIZE=2>> Then can either</FONT>
<BR><FONT SIZE=2>> > end initiate H.245 before CONNECT? If so, what if </FONT>
<BR><FONT SIZE=2>> third party</FONT>
<BR><FONT SIZE=2>> > pause and redirection is initiated before CONNECT?</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > ----</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > François AUDET, Nortel Networks</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> > <A HREF="mailto:audet@nortelnetworks.com">mailto:audet@nortelnetworks.com</A>, tel:+1 408 495 3756</FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> ></FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> --</FONT>
<BR><FONT SIZE=2>> Dr Chris Purvis -- Development Manager</FONT>
<BR><FONT SIZE=2>> ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road</FONT>
<BR><FONT SIZE=2>> Winkfield Row, Berkshire. RG42 6LY ENGLAND</FONT>
<BR><FONT SIZE=2>> Phone: +44 1344 899 007</FONT>
<BR><FONT SIZE=2>> Fax: +44 1344 899 001</FONT>
<BR><FONT SIZE=2>> </FONT>
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