Re: latching vs stream mode=sendonly

Hi Marios,

Latching is a mechanism mainly to provide early bearer on IMS network where there is a big call setup latency involved. e.g. in wireless IUCS operations where there is IUCS signaling involved for early bearer but remote SDP is not known yet.
So this is basically left to implementation to accept remote packet from any IP address & open Pinhole is case of BGF for a certain period of time during call setup till the remote SDP is known thru signaling when latch is set to off & modified to the known remote IP.

In case of BGF it does create a hole in initial session setup as far as security is concerned.

-Arindam

From: [email protected] [mailto:[email protected]] On Behalf Of Aronis, Marios (NSN - GR/Athens)
Sent: Thursday, December 09, 2010 11:58 AM
To: [email protected]
Subject: [Megaco] latching vs stream mode=sendonly

Hello,

 my question concerns the Border Gateway Function in IMS. Assume that a termination on the BGF has been set to stream mode = SendOnly with a modify command that also activates the ipnapt/latch package with latch or relatch. Is this a valid combination? If the BGF next receives a Modify command with stream mode = sendreceive and latch=off, is it expected that latching has occurred in previous step (while in send only mode), so two way communication is allowed ? Could the case be that the BGF drops all incoming traffic since stream mode = sendonly and thus does not latch on the first received packet remote descriptor? I have gone through H248 standards but have not found any clear statement on that, so any reference would be highly appreciated!

Many thanks, Marios


Marios Aronis
BSO VIPT RD VoIP hiQ43 PI

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