I think both TCP and UDP should be provided as options. Particularly with Trunking Gateways TCP can be used as transport mechanism. Since there would be less number of these gateways (in most cases two or four per Call Agent) there will be less number of connections to manage. TCP provides better communication with Trunking gateways in that there is no need to maintain timers and retransmission acks for large number of transactions between Call Agent and Trunking gateway. Three-way hand shaking and retransmission will be costly in this case.
For residential gateways they may be over 10000 per Call Agent. Managing 10000 connections is not a good idea. Also, only 5-10% of the time, residential gateway will communicate with call agent. For this maintaining a connection is big overhead. In this case, UDP is preferred.
IMHO, there is a need to segragate transport profiles for residential gateways and trunking gateways.
Regards
Krishna Kurapati
-----Original Message----- From: Christian Huitema [SMTP:huitema@research.telcordia.com] Sent: Thursday, April 08, 1999 3:40 PM To: Greene, Nancy-M [CAR:5N10:EXCH]; 'megaco@baynetworks.com'; 'itu-sg16@mailbag.intel.com' Subject: Transport issue (was: audio call Thursday: Minutes)
- transport issues
There was discussion on what to use for interoperability purposes until
the
actual transport is agreed on. Some people wanted to mandate TCP for the
MG,
others said UDP + the message acks, + the addition of timers would be better. Are there MG manufacturers that do not want to put TCP in their
MGs,
even if only for demonstration purposes? If there is opposition to TCP
even
for demonstration purposes, then we would go with UDP + message acks, + timers. Chip Sharp reminded us that SGCP worked just fine with UPD,
acks,
and timers. ===> An issue for the mailing list.
Using TCP would be a serious problem in large configurations. Our experience is that UDP+timers has a wider applicability and is not in practice harder to implement than TCP -- you have to manage timers, but then you don't have to manage connections.
-- Christian Huitema ------------------------------ Please note my new address: huitema@research.telcordia.com http://www.telcordia.com/