RE: [Sipforum-discussion] RE: [Sipping] Text support in SIP phones

[Henry Sinnreich <[e-mail]>]

> I want to have your advice if you want to see also SDP 
> examples for the text channel in the sipdev spec, in a 
> separate Text Conversation Best Code of Practice spec, or if 
> there is any plan for a sipdev-technical guideline spec where 
> it could fit.

I believe a short I-D with SDP examples for the text channel would very
productive and could serve as reference for the SIP Telephony Device I-D
and other.

Thanks, Henry

> -----Original Message-----
> From: [e-mail] [mailto:[e-mail]] 
> On Behalf Of Gunnar Hellström
> Sent: Wednesday, June 11, 2003 4:40 PM
> To: Henry Sinnreich; 'Sipping@Ietf. Org'; 
> 'Sipforum-Discussion@Lists. Su. Se'; 'Drage, Keith (Keith)'
> Subject: SV: [Sipforum-discussion] RE: [Sipping] Text support 
> in SIP phones
> 
> 
> OK, I think it would be fine to bring the introduction of 
> real time text conversation up for discussion in the SIPPING group.
> 
> I think that the small requirement statements we have 
> discussed so far for the sipdev specification are sufficient 
> for that level.
> 
> But I have noticed some uncertainty from developers on what 
> SDP to use to open the RFC2793 text channel, and about some 
> other good implementation habits around the text channel. We 
> need to be sure that there is good agreement on such issues, 
> so that we get maximum harmonization and interoperability 
> between implementations. ( real time text conversation in the 
> PSTN has a terrible history of fragmentation and 
> incompatibility, and it is time to make sure that is history now )
> 
> I want to have your advice if you want to see also SDP 
> examples for the text channel in the sipdev spec, in a 
> separate Text Conversation Best Code of Practice spec, or if 
> there is any plan for a sipdev-technical guideline spec where 
> it could fit.
> 
> 
> Gunnar
> 
> -------------------------------------------
> Gunnar Hellström, Omnitor, Renathvägen 2
> SE 121 37 Johanneshov, SWEDEN
> Tel: [phone]  Mob: [phone]
> e-mail: [e-mail]
> web: www.omnitor.se
> 
> 
> > -----Ursprungligt meddelande-----
> > Från: Henry Sinnreich [mailto:[e-mail]]
> > Skickat: den 11 juni 2003 11:59
> > Till: 'Gunnar Hellström'; 'Sipping@Ietf. Org'; 
> > 'Sipforum-Discussion@Lists. Su. Se'; 'Drage, Keith (Keith)'
> > Ämne: RE: [Sipforum-discussion] RE: [Sipping] Text support in SIP 
> > phones
> >
> >
> > Gunnar, thanks for bringing this up! I believe now we can ask for 
> > discussion time at the SIPPING WG meeting.
> >
> > Henry
> >
> > > -----Original Message-----
> > > From: [e-mail]
> > > [mailto:[e-mail]] On Behalf 
> Of Gunnar 
> > > Hellström
> > > Sent: Tuesday, June 10, 2003 2:42 PM
> > > To: Henry Sinnreich; 'Drage, Keith (Keith)'; 'Sipping@Ietf. Org'; 
> > > 'Sipforum-Discussion@Lists. Su. Se'
> > > Subject: SV: [Sipforum-discussion] RE: [Sipping] Text 
> support in SIP 
> > > phones
> > >
> > >
> > > I agree that this discussion starts to get balance into the 
> > > specification of the real time text conversation feature.
> > >
> > > Firstly, I have discovered that I need to explain again 
> that what we 
> > > talk about is a real time, character by character 
> transmission and 
> > > display of text. You can see the thought as it is growing 
> and being 
> > > formed into text. It is a very direct way to have 
> contact, and once 
> > > you have used it, you realize that in some applications it is 
> > > essential to have access to this feature. It has the same 
> immediate 
> > > flow as audio in voice telephony and video in video telephony.
> > >
> > > In fact, there is a name for the three media together, it 
> is called 
> > > Total Conversation.
> > >
> > > It is true that the force behind defining it has come 
> from the needs 
> > > of people with communication related disabilities. But I am sure 
> > > that once commonly implemented, it will become a natural 
> and popular 
> > > feature that is often used during voice calls between most users.
> > >
> > > Instant messaging is also a very handy service. But it 
> goes message 
> > > by message, and therefore does not have the direct touch 
> as the real 
> > > time conversational service in voice, text and video has.
> > >
> > >
> > >
> > > We have a forerunner in the specification of media for 
> the SIP based 
> > > IP Multimedia phone in 3GPP. Maybe we can pick the same style of 
> > > specification. In 3GPP TS 26.235, "Packet switched conversational 
> > > multimedia applications, default codecs", it is specified 
> among the 
> > > enumeration of supported media:
> > >
> > > 6.3	Real time text
> > > 3G PS multimedia terminals offering real time text conversation 
> > > should support ITU-T Recommendation T.140 [25] Text Conversation 
> > > presentation coding.
> > >
> > > And in the chapter on RTP payload, it is specified:
> > >
> > > 9.2	RTP payload
> > > RTP payload formats specified by IETF shall be used for real time 
> > > media streams. RTP payload format for the AMR narrowband speech 
> > > codec is specified in annex B. RTP payload format for the AMR 
> > > wideband speech codec is specified in annex B. RTP payload format 
> > > for the ITU-T Recommendation H.263 [6] video codec is 
> specified in 
> > > IETF RFC 2429 [3]. RTP payload format for the MPEG-4 
> visual simple 
> > > profile level 0 is specified in IETF RFC 3016 [5]. RTP payload 
> > > format for the ITU-T Recommendation T.140 [25] text conversation 
> > > coding is specified in IETF RFC 2793 [24].
> > >
> > > In the annex A on specific details, the following is 
> specified for 
> > > text:
> > >
> > > A.3	Text
> > > Use of the redundancy coding variant specified in RFC 
> 2793 [24] is 
> > > recommended for error resilience.
> > >
> > > --------------------------------
> > > When this topic was handled in 3GPP, there was opposition against 
> > > mentioning the reason for introducing the text feature as being 
> > > something specific for disabled people.
> > >
> > > I think that is still valid.
> > >
> > > I suggest that the following formulation is used:
> > > **************************************************************
> > > **************
> > > **************************************
> > > SIP-zz, digital text support: SIP telephone devices 
> SHOULD support 
> > > real time text conversation. If text is supported, it 
> MUST support 
> > > RFC2793 [y], for text coding and packetization, and it MUST be 
> > > possible to use text simultaneously with voice.
> > > **************************************************************
> > > **************
> > > **************************************
> > >
> > >
> > > Gunnar
> > > -------------------------------------------
> > > Gunnar Hellström, Omnitor, Renathvägen 2
> > > SE 121 37 Johanneshov, SWEDEN
> > > Tel: [phone]  Mob: [phone]
> > > e-mail: [e-mail]
> > > web: www.omnitor.se
> > >
> > >
> > > > -----Ursprungligt meddelande-----
> > > > Från: [e-mail]
> > > > [mailto:[e-mail]]För Henry 
> Sinnreich
> > > > Skickat: den 10 juni 2003 18:02
> > > > Till: 'Drage, Keith (Keith)'; 'Henry Sinnreich'; 'Gunnar
> > > Hellström';
> > > > 'Sipping@Ietf. Org'; 'Sipforum-Discussion@Lists. Su. Se'
> > > > Ämne: [Sipforum-discussion] RE: [Sipping] Text support in SIP 
> > > > phones
> > > >
> > > >
> > > > Keith, thanks for bringing balance, I believe, to this 
> discussion.
> > > >
> > > > We could formulate soemthing like "SIP phones that have a
> > > text display
> > > > and advertised as supporting the hearing or speech disabled 
> > > > MUST..."
> > > >
> > > > Would this be OK?
> > > >
> > > > Henry
> > > >
> > > > > -----Original Message-----
> > > > > From: [e-mail] 
> [mailto:[e-mail]] On 
> > > > > Behalf Of Drage, Keith (Keith)
> > > > > Sent: Tuesday, June 10, 2003 8:14 AM
> > > > > To: 'Henry Sinnreich'; 'Gunnar Hellström'; 
> 'Sipping@Ietf. Org'; 
> > > > > 'Sipforum-Discussion@Lists. Su. Se'
> > > > > Subject: RE: [Sipping] Text support in SIP phones
> > > > >
> > > > >
> > > > > I would suggest that treating these sort of things as
> > > MUST strength
> > > > > is best left to national regulatory requirements, along
> > > with other
> > > > > things like fitness for purpose and so on. I have no 
> objection 
> > > > > to their being mentioned. By the way, I understood 
> this document 
> > > > > was being progressed as authors individual submission, and
> > > was therefore
> > > > > not standards track.
> > > > >
> > > > > Any such MUST would surely need to be qualified 
> anyway. If the 
> > > > > purpose of the devise is such that it renders a 
> textual devise 
> > > > > irrelevant, then why require one to be fitted. 
> Suppose we were 
> > > > > designing a SIP phone for the totally blind, and this was
> > > designed
> > > > > to be worn as a headset, a text device would be
> > > irrelevant to such a
> > > > > user, and positioning such a device where it could be 
> seen would 
> > > > > require an extra box hanging out of the side of the product.
> > > > >
> > > > > regards
> > > > >
> > > > > Keith
> > > > >
> > > > > Keith Drage
> > > > > Lucent Technologies
> > > > > Tel: [phone]
> > > > > Email: [e-mail]
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Henry Sinnreich [mailto:[e-mail]]
> > > > > > Sent: 27 May 2003 17:18
> > > > > > To: 'Gunnar Hellström'; 'Sipping@Ietf. Org'; 
> > > > > > 'Sipforum-Discussion@Lists. Su. Se'
> > > > > > Cc: 'Henry Sinnreich'
> > > > > > Subject: RE: [Sipping] Text support in SIP phones
> > > > > >
> > > > > >
> > > > > > Gunnar, this all seems very reasonable, and I will try
> > > to insert
> > > > > > it properly.
> > > > > >
> > > > > > Henry
> > > > > >
> > > > > > > -----Original Message-----
> > > > > > > From: [e-mail]
> > > [mailto:[e-mail]] On
> > > > > > > Behalf Of Gunnar Hellström
> > > > > > > Sent: Thursday, May 22, 2003 6:54 PM
> > > > > > > To: 'Sipping@Ietf. Org'; Sipforum-Discussion@Lists. Su. Se
> > > > > > > Cc: Henry Sinnreich
> > > > > > > Subject: [Sipping] Text support in SIP phones
> > > > > > >
> > > > > > >
> > > > > > > Sorry, I missed out the reference to the SIP device 
> > > > > > > specification.
> > > > > > >
> > > > > > > Henry and all,
> > > > > > >
> > > > > > > Some time ago, I suggested addition of support 
> for real time 
> > > > > > > text communication to the SIP device specification
> > > > > > >
> > > > > >
> > > > >
> > > 
> http://www.ietf.org/internet-drafts/draft-sinnreich-sipdev-req-00.tx
> > > > > t
> > > > > > >
> > > > > > > This was the simple part of the proposal:
> > > > > > >
> > > > > > > > SIP-zz, digital text support: SIP telephone devices
> > > MUST support
> > > > > > > >   real time text conversation using RFC 2793 [y] for the
> > > > > > > text stream.
> > > > > > > >   It MUST be possible to use text simultaneously with 
> > > > > > > > voice.
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > ---------------------------------------------
> > > > > > > > In 4.11 Ringer Behaviour  : add the section 
> below for the
> > > > > > > purpose of
> > > > > > > > deaf, hearing impaired, deaf-blind people and people in 
> > > > > > > > the
> > > > > > > garden and
> > > > > > > > noisy
> > > > > > > > locations:
> > > > > > > >
> > > > > > > > SIP Telephony devices MUST provide an external
> > > interface to an
> > > > > > > > external alerting system.
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > Add to References
> > > > > > > > -----------------
> > > > > > > > [y] G. Hellstrom: "RTP Payload for Text Conversation.",
> > > > > RFC 2793,
> > > > > > > > IETF, May 2000.
> > > > > > > >
> > > > > > > >
> > > --------------------------------------------------------------
> > > > > > >
> > > > > > > The reception of this proposal was very positive. Now, I 
> > > > > > > would like to see the final formulation, and
> > > check that
> > > > > > > we agree on it.
> > > > > > >
> > > > > > > I regard this requirement to be very light. In 
> the Interface 
> > > > > > > section ( e.g.
> > > > > > > Int-2) , there is already mentioning of mandatory 
> text input 
> > > > > > > mechanisms, and assumptions that a display would 
> be normal, 
> > > > > > > since handling of phone books and buddy lists are
> > > mandatory. To
> > > > > > > re-use these text interface devices during the call for 
> > > > > > > standardised text conversation purposes seems 
> > > > > > > straightforward.
> > > > > > >
> > > > > > > It could be wise to add the T.140 text presentation
> > > protocol as
> > > > > > > a codec to the codec section. The normal SDP used
> > > together with
> > > > > > > RFC2793 for text could also be specified. Do you want
> > > > > > to do that?
> > > > > > >
> > > > > > >
> > > > > > > -----
> > > > > > >
> > > > > > > We also need to check the ideas around the other proposed
> > > > > > > requirements: The requirement to include text
> > > telephone modem in
> > > > > > > all designs where an RJ11 phone connector exists, and the 
> > > > > > > requirement to support RFC 3351. I suggest that we start 
> > > > > > > with the straightforward and mainstream 
> requirement above. 
> > > > > > > Is that accepted as it is?
> > > > > > >
> > > > > > >
> > > > > > > Regards
> > > > > > >
> > > > > > > Gunnar
> > > > > > > -------------------------------------------
> > > > > > > Gunnar Hellström, Omnitor, Renathvägen 2
> > > > > > > SE 121 37 Johanneshov, SWEDEN
> > > > > > > Tel: [phone]  Mob: [phone]
> > > > > > > e-mail: [e-mail]
> > > > > > > web: www.omnitor.se
> > > > > > >
> > > > > > >
> > > > > > >
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> > > > > >
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> >
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> 
> 
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