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[AVT] FW: Clearmode / VoIP Media Gateways supporting ISDN data
Some comments from Study Group 11 relating to the CLEARMODE draft for your
information.
-----Original Message-----
From: Leslie Graf [mailto:Leslie.Graf@ericsson.com.au]
Sent: Monday, October 21, 2002 8:04 PM
To: steve.norreys@bt.com
Cc: kschong@att.com; tsg11bicc@ties.itu.ch
Subject: Re: Clearmode / VoIP Media Gateways supporting ISDN data
Collegues,
Just to add to what Steve has correctly stated. This TMR calue is used for
the 7kHZ ausio service where no network fallback is permited.. This is
certainly not a data service. Regards Leslie
steve.norreys@bt.com wrote:
> Gents
>
> Just because the call is marked as "64Kbits/s unrestricted" does not
> mean that this is a data call in the IP sense of a data call. Some
> customers use this TMR to transfer real time data between applications
> in different networks. That the TMR does not tell you of the type of
> application that is using this "media" so it would be prudent to use
> RTP when interworking ISUP to SIP networks.
>
> Regards
>
> Steve Norreys acd
>
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> -----Original Message-----
> From: Chong, Koan S, ALVAP [mailto:kschong@att.com]
> Sent: 15 October 2002 15:44
> To: tsg11bicc
> Subject: FW: Clearmode / VoIP Media Gateways supporting ISDN data
>
> Please look at the questions at the end of the attached email.
> Regards, Koan
>
> -----Original Message-----
> From: Kreuter Ruediger [mailto:ruediger.kreuter@siemens.com]
> Sent: Tuesday, October 15, 2002 8:45 AM
> To: avt@ietf.org
> Cc: 'danny@tcb.net'; Chong, Koan S, ALVAP
> Subject: Clearmode / VoIP Media Gateways supporting ISDN data
>
> Hi,
>
> in August I published draft-kreuter-avt-rtp-clearmode-00.txt
> with the intention to drive a IANA registration for a Codec that can
> be used to support ISDN data connections via RTP. The main application
> for that are VoIP media gateways replacing a TDM network.
>
> This registration will have an influence on all VoIP media gateways
> and related softswitches in the converged network market, at least in
> interworking cases. Therefore I would like to get some comments by
> suppliers of such gear. Do you agree with this draft (besides from
> typos :-) ? Are there concurrent solutions in the market/field ?
>
> *********************************************************
>
> Another topic to be discussed,
> is a discussion input for a "Coding of SDP Media Description Lines
> from TMR/USI", in case of "Call Interworking from BICC/ ISUP to SIP"
> (ITU, Study Group 11, WP3, Meetings of BICC/SIP interworking in
> Ottawa, Canada, 9th - 13th September 2002).
>
> This ITU standardization input, recommends to use UDP for Nx64kbit/s
> unrestricted connections. ("64kbit/s unrestricted" or "transparent
> mode" are synonyms for "clearmode") In SDP this would look like:
>
> b=AS:64
> m=data <port> udp
>
> This approach leads to two questions:
>
> Is it a good idea to transport ISDN data in VoIP networks directly on
> top of UDP instead of RTP ? This would enforce to rebuild all features
> which currently are based on RTP/RTCP parameters; e.g. synchronization
> (time stamps) or statistics & billing (RTCP sender/receiver
> reports).
>
> And is it necessary to support Nx64kbit/s (with N>1)
> within draft-kreuter-avt-rtp-clearmode-00.txt ?
> That is, is TDM:Nx64kbit/s visible to a VoIP media
> gateway ?
> In that case an additional parameter describing the
> size of N would be needed, and an algorithm describing
> the packetization in case of N>1.
>
> Any opinions according this topic ?
>
> Regards
>
> Ruediger Kreuter
> ruediger.kreuter@siemens.com
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