Subject: RE: [Speechsc] SPEECHSC vs 3GPP

From: "Eric Burger" <[email-masked]>
Date: Thu, 12 Dec 2002 21:13:17 -0500

The Mp interface is (1) not the right concept and (2) is itself (IMHO) not the correct choice for 3GPP's needs, either.

With respect to (1), Mp is trying to be an analog to the MGC/MG decomposition for a media server, where the MRFC is a "media server controller" and the MRFP is a "media server [processor]".  The types of resources are bearer packet processors (e.g., tone detection, prompt playing, and recording).  The protocol is a low-level device control protocol (e.g., allocate a resource, allocate a RTP port, connect the port to the resource, wait for a signal, etc.).  speechsc is a higher-level protocol, concerned with things like 'establish session' and 'recognize speech'.  

In fact, early in the days of MRCP/speechsc, people wanted to extend the speechsc scope to do device control.  The answer has consistently been to use H.248 for device control.

With respect to (2), AFAIK, no one has ever built a MRFC.  I believe this is because unlike a media gateway, where there are definite decomposition benefits, there are really few if any benefits to decomposing the MRF.  In fact, there are clear benefits to using the native application interface (SIP), rather than the native gateway interface (H.248) for interfacing the AS and CSCF to the MRF.

-----Original Message-----
From: Jean Philippe Longeray [mailto:[email-masked]]
Sent: Tuesday, December 10, 2002 5:53 AM
To: IETF SPEECHSC (E-mail)
Subject: [Speechsc] SPEECHSC vs 3GPP

Hi,

Do you ever compare SPEECHSC and MRFC/MRFP interface in 3GPP (TS 24.229 Rel5) architecture. 

It looks like  SPEECHSC  is very closed from Mp interface (H.248).

Could SPEECHSC works with 3GPP (www.3gpp.org) , 3GPP2 (www.3gpp2.org) , 3G.IP (www.3gip.org),  MWIF (www.mwif.org)?

Regards.

Jean-Philippe LONGERAY 
R&D Director - Service NODE

NetCentrex 

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From: "Jean Philippe Longeray" <[email-masked]>
Date: Fri, 13 Dec 2002 08:25:17 +0100

Thanks Eric for this analyze,

I agree. H.248 doesn't seems to be the right answer for MRFC/MRFP, even if
special packages can be provided.

For my opinion, SIP is the correct answer for transport layer (since it's
used everywhere in 3GPP and 3GPP2), and SPEECHSC could (should?) be used for
resource control.

Concerning SPEECHSC, 3.3 "Avoid Duplicating Existing Protocols", I would
like to add some remarks:

In case of you would like to insert a routing mechanism (a SIP soft-switch)
between Media Processing Entity / Application server and Resource server
(ASR, SI/SV, TTS, Announcement server), I could be interesting to have a
single transport protocol, like SIP, instead of several incompatible
protocols (RTSP for example) for the closes functionalities. I think it is
easier to add some redundancy, rather than conserving "old" protocols like
RTSP.

It seems to be very important to make distinctions between each layers of
model.
Something like UDP/SIP/SPEECHSC or TCP/SIP/SPEECHSC or SCTP/SIP/SPEECHSC,
could be an answer.

Regards.

Jean-Philippe LONGERAY

NetCentrex

<mailto:[email-masked]>

-----Original Message-----
From: Eric Burger [mailto:[email-masked]]
Sent: vendredi 13 décembre 2002 03:13
To: Jean Philippe Longeray
Cc: IETF SPEECHSC (E-mail)
Subject: RE: [Speechsc] SPEECHSC vs 3GPP

The Mp interface is (1) not the right concept and (2) is itself (IMHO) not
the correct choice for 3GPP's needs, either.

With respect to (1), Mp is trying to be an analog to the MGC/MG
decomposition for a media server, where the MRFC is a "media server
controller" and the MRFP is a "media server [processor]".  The types of
resources are bearer packet processors (e.g., tone detection, prompt
playing, and recording).  The protocol is a low-level device control
protocol (e.g., allocate a resource, allocate a RTP port, connect the port
to the resource, wait for a signal, etc.).  speechsc is a higher-level
protocol, concerned with things like 'establish session' and 'recognize
speech'.

In fact, early in the days of MRCP/speechsc, people wanted to extend the
speechsc scope to do device control.  The answer has consistently been to
use H.248 for device control.

With respect to (2), AFAIK, no one has ever built a MRFC.  I believe this is
because unlike a media gateway, where there are definite decomposition
benefits, there are really few if any benefits to decomposing the MRF.  In
fact, there are clear benefits to using the native application interface
(SIP), rather than the native gateway interface (H.248) for interfacing the
AS and CSCF to the MRF.

-----Original Message-----
From: Jean Philippe Longeray [mailto:[email-masked]]
Sent: Tuesday, December 10, 2002 5:53 AM
To: IETF SPEECHSC (E-mail)
Subject: [Speechsc] SPEECHSC vs 3GPP

Hi,

Do you ever compare SPEECHSC and MRFC/MRFP interface in 3GPP (TS 24.229
Rel5) architecture.

Could SPEECHSC works with 3GPP (www.3gpp.org) , 3GPP2 (www.3gpp2.org) ,
3G.IP (www.3gip.org),  MWIF (www.mwif.org)?

Regards.

Jean-Philippe LONGERAY

NetCentrex