Re: [OpenSIPStack] is it necessary to parse RTP in openSBC

[Ashish K. <ash...@gm...>]

Hi Joegen,
Please reply for my below mail.


Thanks for the reply.
Is there any design document about openSBC, which will tell me in detail
about how it is implementing the NAtting/ ALG functinality and how it will
handle the Media streams.
For Call Transfer, we will use the relay approach.
Also, if i want to just relay the Media packets, can you let me know the
algorithm you have applied in the openSBC.

Also, in openSBC product, is High Availability supported or it is in roadmap
?


On 8/10/07, Ashish Khare <ash...@gm...> wrote:
>
> Hi Baclor,
>
> Thanks for the reply.
> Is there any design document about openSBC, which will tell me in detail
> about how it is implementing the NAtting/ ALG functinality and how it will
> handle the Media streams.
> For Call  Transfer, we will use the relay approach.
> Also, if i want to just relay the Media packets, can you let me know the
> algorithm you have applied in the openSBC.
>
> Also, in openSBC product, is High Availability supported or it is in
> roadmap ?
>
>
>  On 8/10/07, Joegen E. Baclor <joe...@gm...> wrote:
> >
> > inline...
> >
> >
> > Ashish Khare wrote:
> > > Hi Baclor,
> > > This is still not clear to me.
> > > Lets take a example:
> > > Sip Client A is talking to Sip Client B through Proxy/B2BUA(P) which
> > > handles only SIP signaling messages.
> > > Now in Call, Sip Client A is trasnferred to Sip CLient C and now B and
> > > C are talking.
> > > But still they are abel to talk.
> > > Then how this case is different from yours. Can  you please elaborate
> > > and explain to me.
> >
> > There are two ways OpenSBC handles REFER.  The default is to relay the
> > REFER to the UA and let the UA do the transfer request.   This is ok
> > because the UA knows that there will be a change in the audio session.
> > The second way (Local REFER) will not relay the REFER.   Instead OpenSBC
> > do the transfer.   This leaves the other UA to not know that the call is
> > actually transfered.   If the transfer succeeded, a new media would with
> >
> > a different SSRC would have been created.   If OpenSBC just relays that,
> > the UA may reject the packets because the ssrc has already changed.
> >
> >
> > >
> > > we are considering to build ALG. We have our own SIP stack ( Proxy and
> >
> > > B2BUA ) but we dont have RTP stack.  Also we dont want to parse the
> > > RTP stream. Just Rely it, based on source and destination IP and
> > > ports. Is this feasible ?. We are also exploring your openSBC if we
> > > can used it.
> >
> >
> >
> > Of course this is feasible.  You will have to change some lines of code
> > in the media interface but it wont take much.    Just post questions
> > about the code if you need to clarify something.
> >
> > >
> > >
> > >
> > >
> >
> >
>