Note: the referred text relates to an
Appendix ( = informativ), not to an Annex (= normativ). Thus, just examples, not
there are H.248 profile specifications with
support support of monorate emulation, see
ETSI ES 283 024, Trunking
On IMS/NGN Terminations, Clearmode codec is transported
according to RFC 4040 .
When the MGC determines that a 64 kbit/s
unrestricted bearer service is requested, the clearmode codec shall be used. A
Dynamic Payload type with CLEARMODE as encoding name shall be included in both
the local and remote descriptor.
The behaviour of the TMGW shall then conform
to RFC 4040 . All voice and signal processing functions such as silence
suppression, comfort noise insertion and gain adjustment shall be automatically
turned off. The MG shall inherit the same QoS objectives as the ISDN bearer
However, there was never any H.248
Profile standardized with multirate support, at least
to my knowledge.
Y.2262 PSTN/ISDN emulation and
simulation, Appendix IV
Examples of emulation of PSTN and N-ISDN bearer
(This appendix does not form an integral part of this
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.
Recommendation I.231.1 may be emulated by a single RTP session, with
without RTCP, using RTP clearmode according to IETF RFC 4040.
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
> -----Original Message-----
megaco-bounces <at> ietf.org
> [mailto:megaco-bounces <at> ietf.org
Behalf Of Javi
> Sent: Samstag, 29. Januar 2011 02:13
megaco <at> ietf.org
> Subject: [Megaco] TDMPW and MeGaCo/SDP
Assuming the next situation:
> ISDN Terminal 1 -
MG1 - [IP network] - MG2 - ISDN Terminal
> where the MGs (Media Gateway) are controlled by a MGC (Media
> Controller) via MeGaCo[H.248.1].
> [ITU-T Y.2262 /
Annex IV] proposses that MGs may transport
> ISDN B-channels over the IP
> + By a single RTP session (when monochannels ISDN
> + Or by TDMoIP (= UDP TDMPWs), when multichannels ISDN
> 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?
> Megaco mailing
> Megaco <at> ietf.org