Subject: RE: doubts on SDP

From: Ami Amir <[email-masked]>
Date: Mon, 30 Apr 2001 10:10:13 +0300

Hi

As far as I know, most, if not all MEGACO implementations use SDP (text)
encoding, so you will be standard compliant, but in a small very small
minority of binary implementers.

Ami
 -----Original Message-----
From: 	Christian Groves [mailto:[email-masked]] 
Sent:	Friday, April 27, 2001 9:13 AM
To:	Madhu Babu Brahmanapally
Cc:	[email-masked]; [email-masked]
Subject:	Re: doubts on SDP

Hello Sasi,

You may design a MG that implements H.248 without SDP by using the
binary version of Megaco as it does not use SDP for description in the
Local and remote descriptors.

Cheers, Christian

Madhu Babu Brahmanapally wrote:
> 
> Hi Sasi,
> My answers below with [Madhu]
> Regards
> Madhubabu
> -----Original Message-----
> From: [email-masked]
> [mailto:[email-masked]]On Behalf Of Sasitharan R
> Sent: Wednesday, April 18, 2001 9:38 AM
> To: [email-masked]
> Subject: doubts on SDP
> 
> Hi all,
> 
>     My understanding on the usage of SDP is as follows,
> 
> 1) Media gateway controller (MGC) uses SDP to get the session description
> and properties of terminations from
>     mediagateway(MG). So when MGC initiates any command it uses the values
> given by SDP. If we use SDP MG
>     will give values as fully specified to MG. This is my understanding.
Is
> it correct? If I'm wrong please explain how it will be?
> [Madhu] The MGC can either fully specify, over specify or underspecify the
> values in different fields of SDP. If underspecified, MG has to specify
the
> value it has chosen and send the chosen values in the response. If the MGC
> fully specify, then the MG should validate the support for the specified
> parameters and then respond accordingly.
> 
> 2)  If we design a residential gateway using MGCP and MEGACO, can we do
this
> without having SDP ?
>      Is SDP is a mandatory for any MG ?
> [Madhu] SDP is a mandatory means of exchanging the session description in
> both MGCP and MEGACO. You have to live with that.
> 
> 3)  Is it possible to change a Residential gateway to trunking Gateway ?
If
> so is only signaling is the addition ?
> [Madhu] IMO the packages supported on the Media Gateway decides the
behavior
> of the Gateway. This in turn means that the commands exchanged between the
> MG and MGC decides the operation taken at the MG. The MG and MGC should be
> aware of the behavior of the terminations in the Media Gateway(whether it
is
> RG or TGW). It is definitely possible to change a Residential gateway to
> Trunking gateway.
> 
>      Any body in this mailing list are invited to clarify my doubts.
> 
> Regards and
> thanks in advance,
>     sasi