FYI
-----Original Message----- From: Gunnar Hellstrom [mailto:gunnar.hellstrom@omnitor.se] Sent: 07 June 2005 11:13 To: Text Telephone Forum; STF267 Cc: Björn Troili; eConf Support; Frank Shearar; Andreas Piirimets(Omnitor); Andreas Richter; Kristian Kristiansson; Johan Malmgren; Bill Pechey; Judy Harkins; Paul Jones(Packetizer); Marcelo Tapia; George Skorkowski; Bo Bergner; Robert Hecht; Andrea Saks; Guido Gybels (E-mail); Arnoud van Wijk; Gregg Vanderheiden; TR-30. 1; Campos, Simao; Tom Taylor; Henry Sinnreich; Christian Groves; Pekka. V. Heikkinen; Claes Tjäder Subject: An important step for interoperability and functionality of text communication: RFC 4103 replaces RFC 2793.
An IETF document describing real time text transmission in IP networks is approved and published.
The work with revision of the real time text transport specification RFC 2793 in IETF is completed. During the work, we have called it rfc2793bis. The result is now published as a standards track RFC: RFC 4103 RTP Payload for Text Conversation
By that, RFC 2793 is made obsolete. RFC 4103 is backwards compatible with its predecessor, so the move will be smooth. There are two new parameters to handle. All references to RFC 2793 in other standards can now be read as RFC 4103, and should eventually be replaced in the texts by RFC 4103. This is valid for example for the following documents referring to RFC 2793.
ITU-T H.323 Annex G Text converation and Text SET ITU-T H.248.2 Text, Fax and call discrimination packages ITU-T Draft requirements for text over IP ITU-T Draft V.151 Procedures for the end-to-end connection of analogue PSTN text telephones over an IP network utilizing text relay. ETSI TS 126 235 IP Multimedia default codecs ETSI TS 123 226 Global Text Telephony Stage 2 ETSI Draft EG 202 320 Duplex Universal Speech and Text 3GPP TS 26.235 IP Multimedia default codecs 3GPP TS 23.226 Global Text Telephony Stage 2 draft-ietf-sipping-toip Text over IP requirements draft-sinnreich-sipdev-req SIP telephony device requirements draft-ietf-avt-rfc2833bis RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals draft-ietf-avt-rfc2833bisdata Definition of Events For Modem, FAX, and Text Telephony Signals
The main improvements are: -------------------------- -SDP examples clearly showing how a real time text channel can be negotiated and opened in a SIP session.
-Clear packet layout examples showing various cases with and without redundancy.
-Clearer and stronger recommendations to use the default two levels of redundant transmission to keep the risk for character loss very low.
-Clearer and stronger recommendations to use 300 ms buffering between transmissions in order to keep the risk for character loss very low and to keep bandwidth usage for text very low.
-More explicit recommendations on how to apply security considerations.
-More explicit descriptions of the procedures for recovery from packet loss.
-More explicit descriptions of the procedures for protection from congestion.
By these improvements, I am sure that this RFC will contribute well to good interoperability and high functionality of real time conversation applications including the imnportant text medium as a popular feature improving communications for all.
I and Paul Jones stand as authors, but many more have made this improvement possible by putting efforts into the work.
Thanks to all!
Another related document has also been published. It is RFC 4102 Registration of the text/red MIME Sub-Type.
Here is a copy of the IETF announcements: -------------------------------------------------------------------------- ---------------- -
A new Request for Comments is now available in online RFC libraries.
RFC 4103
Title: RTP Payload for Text Conversation Author(s): G. Hellstrom, P. Jones Status: Standards Track Date: June 2005 Mailbox: gunnar.hellstrom@omnitor.se, paulej@packetizer.com Pages: 20 Characters: 44246 Obsoletes: 2793
I-D Tag: draft-ietf-avt-rfc2793bis-09.txt
URL: ftp://ftp.rfc-editor.org/in-notes/rfc4103.txt
This memo obsoletes RFC 2793; it describes how to carry real-time text conversation session contents in RTP packets. Text conversation session contents are specified in ITU-T Recommendation T.140.
One payload format is described for transmitting text on a separate RTP session dedicated for the transmission of text.
This RTP payload description recommends a method to include redundant text from already transmitted packets in order to reduce the risk of text loss caused by packet loss.
This document is a product of the Audio/Video Transport Working Group of the IETF.
This is now a Proposed Standard Protocol.
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
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A new Request for Comments is now available in online RFC libraries.
RFC 4102
Title: Registration of the text/red MIME Sub-Type Author(s): P. Jones Status: Standards Track Date: June 2005 Mailbox: paulej@packetizer.com Pages: 6 Characters: 11337 Updates/Obsoletes/SeeAlso: None
I-D Tag: draft-ietf-avt-text-red-05.txt
URL: ftp://ftp.rfc-editor.org/in-notes/rfc4102.txt
This document defines the text/red MIME sub-type. "Red" is short for redundant. The actual RTP packetization for this MIME type is specified in RFC 2198.
This document is a product of the Audio/Video Transport Working Group of the IETF.
This is now a Proposed Standard Protocol. ---------------------End of copy---------------------
Regards
Gunnar ------------------------------------------- Gunnar Hellström Omnitor AB Renathvägen 2 SE 121 37 Johanneshov SWEDEN +46 8 556 002 03 Mob: +46 708 204 288 www.omnitor.se Gunnar.Hellstrom@Omnitor.se --------------------------------------------