[SIPForum-discussion] SIP and 3G-324M

Marwan Jabri marwan.jabri at dilithiumnetworks.com
Tue Oct 18 15:56:41 UTC 2005

H.324 is the umbrella system protocol for the delivery of conversational videotelephony over narrowband networks. H.324M refers to H.324 with Annex C (Mobile extensions). The multiplex used is described in the H.223 recommendation of the ITU-T. 3G-324M is the 3GPP adaptation which makes some additional recommendations with respect to audio/video codecs as well as the use of adaptation layers and modem operations. 3G-324M operates over the (typically 64kbps) Circuit Switched bearer of 3G and hence is totally separate from other bearers and the packet system. The 64kbps Circuit Switched bearer is unique to 3G. Setting up 3G-324M calls uses the ITU-T Q.931 protocol between handsets and the infrastructure. Within the infrastructure, ISUP is used.


Marwan Jabri  



From: discussion-bounces at sipforum.org [mailto:discussion-bounces at sipforum.org] On Behalf Of Eric Burger
Sent: Tuesday, October 18, 2005 6:24 AM
To: An open list for discussion of SIP-related topics; An open list for discussion of SIP-related topics
Subject: RE: [SIPForum-discussion] SIP and 3G-324M


H.324m is the multiplex of video sigaling (H.245) and media (typically H.263 and either G.711 or AMR), transported over ISDN (in an H.225.0 multiplex).  In 'sip' networks, SIP takes the call setup roll of ISUP, as well as much of the media negotiation of H.245.

3G SIP networks don't need 2.5G ISDN signaling.  2.5G networks don't use SIP for call setup.

There are products that gateway between SIP/RTP and ISDN/H.225.0

 -----Original Message-----
From:   Irwin Lazar [mailto:ilazar at burtongroup.com]
Sent:   Thu Oct 13 15:51:05 2005
To:     An open list for discussion of SIP-related topics
Subject:        [SIPForum-discussion] SIP and 3G-324M

Hi Folks, I¹m doing a bit of reading on the delivery of video (and
potentially video conferencing) over mobile networks and I¹m beating my head
against a wall trying to understand the respective roles of 3G-H324M and

Am I right in assuming that 3G-324M is a short-term solution for the
delivery of multimedia over 3G networks, and at some point in the future
(presumably after IMS becomes a reality) SIP will replace it?

Or, are they complementary protocols?

Thanks in advance,

Irwin Lazar, CISSP
Senior Analyst, Burton Group
ilazar at burtongroup.com
Phone: 703-742-9659
AIM/iChat/Gizmo/Google/Skype: imlazar

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