Re: TDMPW and MeGaCo/SDP
Javi <[email protected]> Tue, 01 Feb 2011 17:50:45 +0100
| Newsgroups | gmane.ietf.megaco |
|---|---|
| Message-ID | <[email protected]> |
El 01/02/2011 15:11, Schwarz, Albrecht (Albrecht) escribió:
> /To H.248 Media Descriptor for IP bearer:/
>
> *
> /your proposal would be insufficient, Y.1453 defines not a
> single, but multiple possible modes of TDMoIP interworking! /
> *
> /See § 7.2/Y.1453 concerning information elements for TDMoIP
> control (=> ´correspondent SDP must be defined if the Y.1453
> provisioning approach would be replaced by an SDP-based
> signalling approach (for TDMoIP IWFs embedded in H.248 MGs or
> SIP VoiceGateways)./
>
I agree. could you propose an possible example of SDP descriptions for
TDMPWs?
> /
> /To H.248 Media Descriptor for TDM bearer:/
>
> *
> /the MUX approach is just an option!/
> *
> /alternatives, e.g., the "the group-and-member scheme (addrtype
> is "GRP")" as proposed by Tom in his SDP-TDM draft
> (http://www.watersprings.org/pub/id/draft-taylor-mmusic-sdp-tdm-01.txt)/
>
> /
Is GRP suitable for MeGaCo?:
The NUL scheme is suitable for use with media gateway control, since
other means are available (as mentioned above) for designating the
TDM circuit.
If NUL is useful for MeGaCo, I assumed GRP is for SIP only.
Version "01" removed Nx64 services:
1.4 Changes From The Previous Version
The main change from the previous version has been to limit the
scope of the present document by placing greater reliance on the
Megaco/H.248 multiplex concept. This has meant the removal of wideband
or aggregated N x 64 kbit/s service from the scope of thedocument
>
> ------------------------------------------------------------------------
> *From:* Javi Muñoz [mailto:[email protected]]
> *Sent:* Dienstag, 1. Februar 2011 14:07
> *To:* [email protected]
> *Subject:* Re: [Megaco] TDMPW and MeGaCo/SDP
>
> H.248 MUX termination (N x B channels) is a good choice at ISDN
> termination.
>
> But, at IP side, we still need to describe TDMoIP in SDP. For
> instance, we may propose any like this:
>
> m=audio <puerto> RTP/AVP <PT_dinámico>
> a=rtpmap:<PT_dinámico> TDMoIP/8000
>
>
>
>
>
> El 31/01/2011 16:54, Schwarz, Albrecht (Albrecht) escribió:
>> /Just some high-level indications:/
>> //
>> /Multirate means effectively N-out-of-K (with K = 24 or 30
>> dependent on ANSI /ETSI markets; and 1 < N <= K)./
>> /That's a first requirement./
>> /Secondly, the selection of channels may be random, they must not
>> be in consecutive order (e.g., think about the permutations for N
>> = 5)./
>> /Thirdly, there could be a dependency of the choosen CESoIP
>> emulation service to the H.248 connection model./
>> //
>> /Possible solution: H.248 MUX termination ... at the high-level .../
>> //
>>
>> ------------------------------------------------------------------------
>> *From:* Javi [mailto:[email protected]]
>> *Sent:* Montag, 31. Januar 2011 11:47
>> *To:* [email protected]
>> *Subject:* Re: [Megaco] TDMPW and MeGaCo/SDP
>>
>> I agree, TDMoIP is an option only.
>>
>> But, if it is used, MGC would use SDP at Local/Remote MeGaCo
>> descriptors. How may be that SDP description for TDMoIP?
>>
>>> However, there was never any H.248 Profile standardized with
>>> /*multirate*/ support, at least to my knowledge.
>>> (I'm aware of vendor specific profile, but that are
>>> proprietary solutions.)
>>>
>>
>> I would be interested to know any of that proprietary
>> solutions. May you indicate me any?
>>
>>>
>>> __
>>> /*Y.2262 PSTN/ISDN emulation and simulation, Appendix IV
>>> Examples of emulation of PSTN and N-ISDN bearer services
>>> *(This appendix does not form an integral part of this
>>> Recommendation)
>>>
>>> Examples for the emulation of PSTN and N-ISDN bearer
>>> services are provided:
>>>
>>> 1) Monorate bearer services (= 1 × 64-kbit/s digital bearer
>>> in PSTN/ISDN)
>>> . ITU-T Recommendations I.231.2 and I.231.3 may be emulated
>>> by a single RTP
>>> session, with or without RTP control protocol (RTCP), using
>>> an RTP profile according
>>> to IETF RFC 3551.
>>> . ITU-T Recommendation I.231.1 may be emulated by a single
>>> RTP session, with or
>>> without RTCP, using RTP clearmode according to IETF RFC 4040.
>>>
>>> 2) Multirate bearer services (= N × 64-kbit/s digital bearer
>>> in PSTN/ISDN; N greater than one)
>>> . ITU-T Recommendations I.231.4 to I.231.10 may be emulated
>>> by TDMoIP described
>>> in ITU-T Recommendation Y.1453.
>>>
>>> /
>>> > -----Original Message-----
>>> > From: [email protected]
>>> > [mailto:[email protected]] On Behalf Of Javi
>>> > Sent: Samstag, 29. Januar 2011 02:13
>>> > To: [email protected]
>>> > Subject: [Megaco] TDMPW and MeGaCo/SDP
>>> >
>>> > Assuming the next situation:
>>> >
>>> > ISDN Terminal 1 - MG1 - [IP network] - MG2 - ISDN
>>> Terminal 2
>>> >
>>> > where the MGs (Media Gateway) are controlled by a MGC
>>> (Media Gateway
>>> > Controller) via MeGaCo[H.248.1].
>>> >
>>> > [ITU-T Y.2262 / Annex IV] proposses that MGs may transport
>>> > ISDN B-channels over the IP network:
>>> >
>>> > + By a single RTP session (when monochannels ISDN services)
>>> >
>>> > + Or by TDMoIP (= UDP TDMPWs), when multichannels ISDN
>>> services.
>>> >
>>> >
>>> > How may MGC indicate to the MG that it uses PWs at the IP
>>> termination?
>>> >
>>> > It may be done by MeGaCo, using SDP[RFC4566] at Local/Remote
>>> > descriptors. However, how may be that SDP description of
>>> TDMPWs?
>>> >
>>> > Thanks,
>>> >
>>> > Javier Muñoz
>>> >
>>> >
>>> > _______________________________________________
>>> > Megaco mailing list
>>> > [email protected]
>>> > https://www.ietf.org/mailman/listinfo/megaco
>>> >
>>
>
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