Re: Multiple Streams and mutiplex terminations

Christian Groves <[email protected]> Fri, 28 Oct 2011 12:23:31 +1100
Newsgroups gmane.ietf.megaco
Message-ID <[email protected]>
Hello Javi,

I'm not aware of any SDP that would allow you to specify the TEI and 
SAPI. Probably the closest draft to doing this was Tom's draft 
http://tools.ietf.org/id/draft-taylor-mmusic-sdp-tdm-01.txt.

Rather than use SDP you probably need to create a new package with two 
properties that allow you to indicate the SAPI and TEI. Each property 
would be a sub-list allowing you to indicate with SAPIs and TEIs apply 
to the stream. You probably wouldn't need multiple StreamIDs in this case.

Regards, Christian

On 25/10/2011 10:51 PM, Javi Muñoz wrote:
> Hello Christian,
>
> Thank you for your answer.
>
> I understand MeGaCo syntax doesn't support adding streams in the 
> multiplex descriptor neither including N in the multiplex descriptor.
>
> [Christian] A little, I understand the termination aspect. I'm still 
> not sure about the streams. I don't understand how you can have 
> multiple H.248 streams for the circuit termination TermA and TermB? 
> With what information element (i.e. property) do you assign the SAPI 
> and TEI to a Stream? What properties distinguish the Nx64K termination 
> from a HDLCW1 one?
> [Christian] I'm not 100% sure what you're trying to do but if you're 
> only using a single Termination to represent each D-channel and a 
> single Termination for the HDLCPW it seems to me that you don't need a 
> mux termination and that it may be sufficient to simply use a property 
> to assign TEIs to Streams (or Terminations).
> [Christian] I think you're trying to solve this at a different level 
> than what it should be. The multiplex descriptor describe the 
> multiplex of terminations used to make up a stream. It doesn't 
> describe what's happening at a stream level itself. We have the Stream 
> Descriptor with associated (Local, Remote, LocalControl descriptors) 
> to do this.
>
>
> In ISDN, each D-channel (channel of 16 or 64 kbps) transport multiple 
> flows muliplexed by its TEI and SAPI in the Q.921 header.
>
> Every of these flows may need to be transported to a different server 
> in the IP network, and each server may receive only a HDLCPW. So, I 
> need to multiplex multiple D-channel flows in each HDLCPW. In each 
> HDLCPW, each flow would be distinguished by its TEI/SAPI and D-channel 
> identifier.
>
> I can not think how to describe in SDP (Local, Remote, LocalControl 
> descriptors) what D-channel flows must be transported by any HDLCPW. 
> May you proposed an example?
>
> Regards,
>
> Javier Muñoz
>>>
>>>
>>>>
>>>>
>>>>
>>>> Regards,
>>>>
>>>> Javi Muñoz
>>>>
>>>>
>>>> El 20/10/2011 11:12, Christian Groves escribió:
>>>>> Hello Javi,
>>>>>
>>>>> Did you see my email on the 18/10 which discusses this? Even with
>>>>> the clarification of the Terminations there's some questions.
>>>>>
>>>>> Regards, Christian
>>>>>
>>>>> On 20/10/2011 7:38 PM, Javi Muñoz wrote:
>>>>>> Does MeGaCo support the next contexts?:
>>>>>>
>>>>>>
>>>>>>
>>>>>> Tmux1=Mux(1x64K(TermA/StreamID=1,TermA/StreamID=2,TermB/StreamID=1))
>>>>>> -- * -- TermC (HDLCPW1)
>>>>>>                                     |
>>>>>> TermA (ISDN D-Channel, UNI p)       |
>>>>>>    StreamID=1 (SAPI 16, TEI r)------|
>>>>>>    StreamID=2 (SAPI 16, TEI s)------|
>>>>>>                                     |
>>>>>> TermB (ISDN D-Channel, UNI q)       |
>>>>>>    StreamID=1 (SAPI 16, TEI r)------|
>>>>>>    StreamID=2 (SAPI 16, TEI s)------------|
>>>>>>    StreamID=3 (SAPI 16, TEI t)------------|
>>>>>>                                           |
>>>>>>
>>>>>> Tmux2=Mux(1x64K(TermB/StreamID=2,TermB/StreamID=3) -- * -- TermD
>>>>>> (HDLCPW2)
>>>>>>
>>>>>>
>>>>>> where:
>>>>>>
>>>>>> (a) Every multiplex termination is multiplexing Streams from
>>>>>> different ISDN terminations, and only any Streams of each
>>>>>> termination.
>>>>>>
>>>>>> (b) The result of the multiplexion must be a flow of "64 kbps".
>>>>>>
>>>>>> Javi Muñoz
>>>>>> _______________________________________________
>>>>>> Megaco mailing list
>>>>>> [email protected]
>>>>>> https://www.ietf.org/mailman/listinfo/megaco
>>>>>>
>>>>> _______________________________________________
>>>>> Megaco mailing list
>>>>> [email protected]
>>>>> https://www.ietf.org/mailman/listinfo/megaco
>>>>>
>>>>
>>>>
>>>
>
> _______________________________________________
> Megaco mailing list
> [email protected]
> https://www.ietf.org/mailman/listinfo/megaco
>