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ITU-T H.323 Annex P (01/2003)

Transfer of modem signals over H.323

This annex defines the signalling procedures to facilitate the transfer of modem signals over H.323-based networks, including the advertisement of capabilities and specific procedures for opening and closing channels that support the transport of modem signals over IP networks. Modem signals may be carried over a packet-based network using either a voice-band data channel or a modem relay channel.

Citation:	https://handle.itu.int/11.1002/1000/6221
Series title:	H series: Audiovisual and multimedia systems H.200-H.499: Infrastructure of audiovisual services H.300-H.349: Systems and terminal equipment for audiovisual services
Approval date:	2003-01-13
Approval process:	AAP
Status:	Superseded
Observation:	Annex P was integrated to H.323 (07/2003) without further modifications
Maintenance responsibility:	ITU-T Study Group 21
Further details:	Patent statement(s) Development history

Ed.	ITU-T Recommendation	Status	Summary	Table of Contents	Download
8	H.323 (V8) (03/2022)	In force	here	here	here
7.1	H.323 (2009) Amd. 1 (03/2013)	Superseded	here	-	here
7	H.323 (12/2009)	Superseded	here	here	here
6	H.323 (06/2006)	Superseded	here	here	here
5.2	H.323 (2003) Amd. 2 (01/2005)	Superseded	here	here	here
5.1	H.323 (2003) Amd. 1 (01/2005)	Superseded	here	here	here
5.0	H.323 (2003) Err. 1 (03/2006)	Superseded	-	-	here
5	H.323 (07/2003)	Superseded	here	here	here
4.6	H.323 Annex O (07/2003)	Superseded	-	-	Not available
4.5	H.323 Annex P (01/2003)	Superseded	here	here	here
4.4	H.323 Annex R (07/2001)	Superseded	here	here	here
4.3	H.323 Annex Q (07/2001)	Superseded	here	here	here
4.2	H.323 Annex M3 (07/2001)	Superseded	here	here	here
4.1	H.323 Annex L (03/2001)	Superseded	-	-	here
4	H.323 (11/2000)	Superseded	here	here	here
3.1	H.323 Annex G (02/2000)	Superseded	-	here	here
3	H.323 (09/1999)	Superseded	here	here	here
2.3	H.323 Annex F (05/1999)	Superseded	here	here	here
2.2	H.323 Annex E (05/1999)	Superseded	here	here	here
2.1	H.323 Annex D (09/1998)	Superseded	-	-	here
2	H.323 (02/1998)	Superseded	here	here	here
1	H.323 (11/1996)	Superseded	-	-	here


ITU-T Supplement	Title	Status	Summary	Table of contents	Download
H Suppl. 6 (04/2006)	Control load quantum for decomposed gateways	In force	here	here	here
H Suppl. 9 (05/2008)	Gateway control protocol: Operation of H.248 with H.225.0, SIP, and ISUP in support of emergency telecommunications service (ETS)/international emergency preference scheme (IEPS)	In force	here	here	here
H Suppl. 10 (05/2008)	Proxy-aided NAT/FW traversal scheme for ITU-T H.323 multimedia systems	In force	here	here	here
H Suppl. 11 (02/2009)	Analysis of class-based home network QoS solutions	In force	here	here	here
H Suppl. 12 (11/2013)	Gateway control protocol: Priority traffic treatment by ITU-T H.248 gateways	In force	here	here	here
H Suppl. 13 (10/2015)	Gateway control protocol: Common ITU-T H.248 terminology - Release 2	In force	here	here	here
H Suppl. 14 (10/2015)	Gateway control protocol: SDP codepoints for gateway control - Release 2	In force	here	here	here
H Suppl. 15 (01/2017)	Conversion and coding practices for HDR/WCG Y'CbCr 4:2:0 video with PQ transfer characteristics	In force	here	here	here
H Suppl. 17 (11/2014)	Guide for addressing accessibility in standards	In force	here	here	here
H Suppl. 18 (10/2017)	Signalling, backward compatibility and display adaptation for HDR/WCG video coding	In force	here	here	here
H Suppl. 19 (04/2021)	Usage of video signal type code points	In force	here	here	here
H Suppl. 21 (01/2025)	Film grain synthesis technology for video applications	In force	here	-	here

Title	Approved on	Download
Testing of personal audio systems for compliance with ITU-T H.870 (2018)	2024	here
Testing of personal audio systems for compliance with ITU-T H.870 (2018)	2021	here
AMS Requirements	2011	here
Service Mobility for new Multimedia Service Architecture	2008	here
Firewall and NAT Traversal Problems in H.323 Systems	2006	here
Telecommunications Accessibility Checklist	2006	here
Usage of the H.510 protocol for the support of H.323 based Multimedia Services within GPRS/IMT2000 networks	2005	here
Requirements for Network Address Translator and Firewall Traversal of H.323 Multimedia Systems	2005	here

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ITU-T Recommendations

ITU-T H.323 Annex P (01/2003)