login | register
Sat 04 of Jul, 2009 [21:03 UTC]

voip-info.org

History

VOIP and TTY

Created by: admin,Last modification on Thu 19 of Jun, 2008 [12:17 UTC] by pejo
TTY (Teletype) and the later term TDD (Telecommunications Device for the Deaf) is a technology used by the hearing impaired to communicate over the phone. In the USA support of TTY is required in some public places (call centers, hotels, etc).

Asterisk has some basic Alpha level code (as of December 2006) with support for TTY.
There is some additional information available at tdd mode. Asterisk svn trunk
has support for T.140 Real-time text and improvements on the TDD mode
in zaptel. TDD support is being developed in SIP too as well as a TDD gateway between
zaptel (analog devices) and SIP/T.140 realtime text in RTP.

See Also


Comments

Comments Filter
222

333More info on TDD/TTY over SIP

by jjblitz, Monday 20 of April, 2009 [21:34:05 UTC]
I'm very interested to hear where this is at in the development cycle. Have been looking for this info and haven't been able to confirm, even with Digium, that the implementation via SIP is even being considered.
222

333ToIP ?

by GehirnJogging, Friday 25 of January, 2008 [16:00:18 UTC]
ToIP, never heard of thet one...
222

333New Text-over-IP protocol

by btdingle, Wednesday 31 of May, 2006 [02:28:50 UTC]
A new real-time Text protocol has been developed. It is often referred to as ToIP. It has been defined by the IETF in RFC 4103. It is very similar to VoIP as it uses the SIP control protocol and a Variation on the RTP protocol. It works on the ordinary Internet - that is, without added QoS - because it has built-in real-time error correction. A trial version of User Application that uses this ToIP protocol is called SIPcon1 and is available from SourceForge.net. Try a Google on SIPcon1. It works really well.
ToIP is designed to be part of the Voice/Video/Text-over-IP multi-play services that are being developed today. It is aimed at mainstream use with some features included to make it easier to interwork with TTYs text phones that operate on telephone networks.
TTYs were developed for analog telephone networks. ToIP was developed to use all the features of the Internet. /Barry