Thread Subject: Re: RFC 4103 reference for real-time text.

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From: Gregg Vanderheiden
Date: Tue, Jun 12 2007 11:20 PM

Hi Paul,



Thanks.



Just so people aren't confused - let me state the current language in the
telecom proposal



The current language does no propose that all phones be made into text
phones.



Availability: What is proposed is

1) EITHER support real time text OR provide a way to connect a phone
that does support text in parallel. (This is basically the same as today
with TTY)

2) IF an IP PHONE *already* has a multi-line display - THEN display IP
text that you receive (this is software only)

3) IF an IP PHONE *already* has a keyboard or allows a keyboard
interface - THEN allow the phone to send IP text. (this is software only
again)



Reliability: That all telecom systems support some type of reliable IP text
format. (Standard within the system but different closed systems can use
different technologies)



Interoperability: That all systems and devices that connect to the public
phone system support the standard format for the system to ensure
interoperability.

- for PSTN that is TIA 825

- for IP SIP it would be RFC 4103 (though there is also a proposal
on the list so support BOTH RFC-4103 and RFC-4351)










Gregg
-- ------------------------------
Gregg C Vanderheiden Ph.D.






_____


From: = EMAIL ADDRESS REMOVED =
[mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Paul E. Jones
Sent: Saturday, June 09, 2007 4:32 PM
To: 'TEITAC Telecommunications Subcommittee'
Subject: Re: [teitac-telecom] RFC 4103 reference for real-time text.

Gregg,



I still do not think it is a good idea to require every phone to support
real-times text. Not every phone today supports text, while they certainly
could. Baudot is trivial, the it could be integrated into my wireless phone
very easily. But, that's not what I would want to use!



I think we need to "be careful what we ask for", otherwise what we might
have is a large number of inferior devices and then people asking, "what
more do you want?"" There might be a resistance to consider making other
options available.



Today, not every phone is accessible. But, what is accessible is the phone
network. A user can use his equipment (or provided equipment) and access
the PSTN to communicate with anybody in the world. They key is "network
access", not "phone access". If we wanted to mandate public phones have
integrated RFC 4103 capabilities, fine. Those are closed systems that might
offer no other interface. Or will they? It might be possible to use an
external text device that works wirelessly with the public phone as a
"natural extension" of the phone. (Never discount the possibility that
technology might evolve in the future into something quite different than
what we have today. I am working on just such a new kind of system.
Whether it sees the light of day is another matter, but we should at least
consider how technology is ever-changing and more sophisticated.)



What I would personally want to be able to use is a Pocket PC, Ultra Mobile
PC (UMPC) or other device with communication software installed. I would
like to have a means to access the network, such as via an Ethernet
connection or a wireless access point. (It's not too hard for me to imagine
that a business could establish a VLAN specifically for such purposes: I
have the equipment necessary to do that in my house, so it's not beyond
reach.)



So, I would encourage you to consider the network, not the phone, as the
focal point for accessibility. This will enable users to have a wider
variety of options, including portable PC devices, dedicated textphones,
PCs, or other devices.



Paul





From: = EMAIL ADDRESS REMOVED =
[mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Gregg
Vanderheiden
Sent: Friday, June 08, 2007 4:24 PM
To: 'TEITAC Telecommunications Subcommittee'
Subject: Re: [teitac-telecom] RFC 4103 reference for real-time text.



TTY is critical on PSTN. It is the only thing that works there.



But it does not work well and is very limiting on IP. Like cellular
phones, (that also can't transport TTY tones natively without destroying
them, the strategy is to convert to a data format where there system
connects to the PSTN.



V.151 is a protocol designed to work between gateways. It is great there.







We need protocols between VoIP phones and between VoIP phones and gateways.




The best I can see is a hybrid approach.





1) Require that all VoIP phones, routers etc support both RFC-4103 and
and RFC-4351 - WHERE THEY CONNECT TO PUBLIC IP SIP SYSTEMS - OR CONNECT TO
OTHER SYSTEMS. (Internally within their own systems where they control
both ends and intermediate routers, they can use anything that meets the
reliability requirements ).

2) PSTN to IP Gateways would also support both but could give
preference to RFC-4351 (offer it first) so that they can save a port for
each call. (if everyone supports both as they should - then RFC-4351 would
work first time.

3) On non public systems (Skype, Vonnage, Corporations Internal
systems, etc) any text transport that meets the requirements is allowed as
long as it is translated into TTY at any PSTN interface and into RFC04103
and 4351 at any external IP SIP interface.





Would this hit the major issues?




Gregg
-- ------------------------------
Gregg C Vanderheiden Ph.D.

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