Linh, Another benefit of using a single TCP connection is that it makes scaleable gatekeeper farms much easier to implement. For example, you can get boxes that will sit in front of multiple HTTP servers to spread the load. These use some algorithm to distribute the various TCP connections. For H.323, it is likely that with two TCP connections, the Q.931 TCP connection and the H.245 TCP connection would end up on different machines. This makes the design difficult if not impossible! Pete ================================= Pete Cordell BT Labs E-Mail: pete.cordell@bt-sys.bt.co.uk Tel: +44 1473 646436 Fax: +44 1473 645499 =================================

---------- From: Hong Linh Truong[SMTP:hlt@ZURICH.IBM.COM] Sent: 19 December 1997 10:38 To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Analysing fast start

Without having analysed all the details, I believe Pete's fast start approach has the following advantages compared to the one currently included in H.323 V2: Having only one TCP connection instead of two not only makes H.323 more scalable, it also simplifies the coordination and the handling of race conditions between Q.931 and H.245. It allows re-use of codes written for the ad-hoc conferencing, because it does not change anything to the H.245 procedures, it just moves them to the H.225 control channel. Linh

------------------------------------------------------------ Hong Linh Truong IBM Zurich Research Lab. SMTP: hlt@zurich.ibm.com Saeumerstr. 4 Notes: Hong Linh Truong/Zurich/IBM@Zurich@IBM_INTERNAL CH-8803 Rueschlikon Switzerland phone: +41 1 724 8434 fax: +41 1 724 8955