Re: [MMUSIC] T.38 (Re: M-line philosophy (Re: Wisdom sought: Prioritization of codecs))

Hi Partha,
On 2012-11-23 17:23, Parthasarathi R wrote:
> Stefan,
>
> I agree with you that usecase does not exists.
>
> I think that T.38 shall be considered as part of PSTN interop as DTMF
> usecase is already considered for PSTN interop. In fact, DTMF interop with
> PSTN gateway shall be easily achieved using non-media (RTP) mechanism but it
> is tough achieve real-time fax interop without media (T.38) support.

This is correct AFAIK. And personally I did not really want DTMF as part 
of rtcweb - it is just for legacy interop, and can be solved by other 
means as you point out. But the wg's view was that sending DTMF should 
be supported, and perhaps that makes sense - DTMF is quite often used, 
by a lot of people (I use it almost daily to navigate IVRs).

I don't think this goes for fax, I think fax these days is only used by 
certain (few) organizations and only for certain types of communication.

But if you think differently, please make a proposal on the rtcweb mail 
list!

Thanks,
Stefan

>
> Thanks
> Partha
>
> -----Original Message-----
> From: mmusic-bounces@ietf.org [mailto:mmusic-bounces@ietf.org] On Behalf Of
> Stefan Hakansson LK
> Sent: Friday, November 23, 2012 4:39 PM
> To: mmusic@ietf.org
> Subject: Re: [MMUSIC] T.38 (Re: M-line philosophy (Re: Wisdom sought:
> Prioritization of codecs))
>
> Thanks for the clarifications, and I agree to what rtcweb/webrtc should
> decide.
>
> What I was implying in my original mail is that I think T.38 support
> should not be added to browsers (at least not as part of the
> rtcweb/webrtc effort), and there are at least two reasons:
>
> * It is not in any of the use-cases
> * You can support store-and-forward FoIP in browsers already
>
> But this discussion should happen in the rtcweb/webrtc space.
>
> Stefan
>
> On 11/22/2012 02:59 PM, Schwarz, Albrecht (Albrecht) wrote:
>> Looks like that your are describing T.37 FoIP behaviour, whereas Adam
>> did point on T.38 FoIP.
>>
>> WebRTC should firstly agree
>> a) whether fax is part of this conversational realtime multimedia
>> service at all,
>> and if,
>> b) which transport mode via IP.
>>
>> To a): support of F.185 (Internet fax) Yes/No
>> To b):
>>       b.1) T.37 FoIP store-and-forward already sufficient Yes/No
>>       b.2) T.38 FoIP realtime required Yes/No ((perhaps T.38 over RTP/UDP
>> or UDPTL/UDP))
>>       b.3) or any alternative to T.38 FoIP realtime Yes/No
>>
>> NOTE: T.38 would specify the behaviour of the
>> 1) PSTN gateway (as "T.38 gateway", which is always a PSTN-to-IP
>> gateway) and
>> 2) Browser (as "T.38 IAD" (Internet aware fax device))
>> in below illustration.
>>
>> -Albrecht
>>
>> -----Original Message-----
>> From: mmusic-bounces at ietf.org [mailto:mmusic-bounces at ietf.org] On
>> Behalf Of Stefan Hakansson LK
>> Sent: Donnerstag, 22. November 2012 14:39
>> To: mmusic at ietf.org
>> Subject: Re: [MMUSIC] T.38 (Re: M-line philosophy (Re: Wisdom sought:
>> Prioritization of codecs))
>>
>> On 11/20/2012 15:56, Adam Roach wrote:
>>   >
>>   >
>>   >    +---------+   +------------+   +---------+
>>   >    | Web App |---| SIP Server |---|         |
>>   >    +---------+   +------------+   |         | +-------------+
>>   >         |                         | PSTN GW |--| Fax Machine |
>>   >    +---------+      media         |         | +-------------+
>>   >    | Browser |--------------------|         |
>>   >    +---------+                    +---------+
>>
>> For cases when one client is not a proper fax machine, is not the usual
>> thing that is done that the facsimile is converted to/from TIFF, JPEG,
>> PDF or similar somewhere between that client and the fax machine? (And
>> often sent as a mail attachment)
>>
>> If so, all tools are already available (e.g. File API if you want to
>> store/access on the local file system, XHR or WebSockets - or even the
>> rtcweb data channel for transport) to build a client that can handle
>> fax. (I am probably missing something)
>>
>> Stefan
>>
>> _______________________________________________
>> mmusic mailing list
>> mmusic at ietf.org
>> https://www.ietf.org/mailman/listinfo/mmusic
>
>
>
> _______________________________________________
> mmusic mailing list
> mmusic@ietf.org
> https://www.ietf.org/mailman/listinfo/mmusic
>