[Serusers] Asigning a Subscriber to a Specific rtpproxy

sip sip at arcdiv.com
Sun Oct 9 03:33:44 CEST 2005


What you're essentially doing is geographical load balancing of the RTP
streams based on origin location. I simply can't think of a way to do this
with rtpproxy because when you call rtpproxy, you give it the remote location
of the proxy server externally from SER (so there's no way SER could figure
out where to send things based on origin location). 

Mediaproxy, using SRV records, could do what you want but you'd need to
essentially have differing DNS records for each local ISP and ASSUME (and
that's a big assumption) that the users are using the ISP's DNS, so their SRV
record lookups would return the local Mediaproxy server. 

Of course, now that I think about it, it's probably not the client side of
things that determines the mediaproxy server location with DNS but the SER
server itself, so that probably wouldn't work either. 

There's no EASY solution for transparency, I don't think. You could specify an
outbound proxy in the config of the UA and then use DNS local to each ISP to
reroute that to a local RTPProxy server, but that takes the logic out of the
hands of SER completely (which is really what you have to do). 

SER itself doesn't really determine anything about the RTP stream. It's only
used for the signalling stream, so in order to route to alternate RTP proxies,
you'd need some sort of external method of doing so. RTPproxy itself doesn't
have that capability. Nor does Mediaproxy, really.  

Your only real bet for doing that would be, as I said, requiring a
configuration option of the outbound proxy server and then shadowing DNS at
each ISP in order to maintain alternate locations for the clients to go to. 

You could, I suppose, create different versions of the mediaproxy module or
nathelper module in order to run multiple instances of the media forwarders
based on a SER lookup of the origin IP... but that would be MESSY. It would
WORK. It would be transparent... but it's hardly an elegant solution. ;)

N.


On Sat, 08 Oct 2005 18:19:16 -0400, Andres wrote
> The idea here is not to load balance or distribute media streams 
> using SRV records.  I do know mediaproxy supports that.  But the 
> idea is that if we have 1000 users at ISP A, we might decide to 
> collocate a server 
> (with rtpproxy or mediaproxy) with them so we can guarantee 
> latencies of under 10ms.
> 
> We are not talking about guess work here.  This is about a carefully 
> designed plan, hand-to-hand with the ISP(s) in question.  So what we 
> need to figure out is how can our 1000 users at ISP #1 use MEDIAPROXY 
> #1, 1000 users at ISP #2, use MEDIAPROXY #2, and so forth.
> 
> If it can't be done then certainly splitting up the users into 
> different SER servers can do the trick, but we wanted to ask around first.
> 
> Thanks,
> Andres.
> 
> sip wrote:
> 
> >I can't think of a way to do that with RTPProxy offhand, but Mediaproxy is
> >designed specifically for that sort of thing using DNS srv records and the
> >like to distribute proxy loads. 
> >
> >Geographic distribution, however, isn't as impotant as some sort of
> >least-cost-routing concept... the idea being that even if I have a proxy
> >server in the room next to me, if it's connected via a network segment that's
> >overall slower or has more hops than the server across town, then the one
> >across town is going to be the better server for my needs. 
> >
> >N.
> >
> >On Sat, 08 Oct 2005 10:45:34 -0400, Andres wrote
> >  
> >
> >>Hi,
> >>
> >>Can anybody think of a way to assign a subscriber's call to a 
> >>specific rtpproxy?  The idea is to have one main SER server but 
> >>multiple rtpproxy servers handling the media stream close to where 
> >>the subs are.  The SER server can be a continent away but the 
> >>rtpproxy is in the same city as the users.  I was thinking of using 
> >>ACL (groups) somehow but not sure if it is at all possible.
> >>
> >>Any ideas?
> >>
> >>Thanks,
> >>
> >>-- 
> >>Andres
> >>Network Admin
> >>http://www.telesip.net
> >>
> >>_______________________________________________
> >>Serusers mailing list
> >>serusers at lists.iptel.org
> >>http://lists.iptel.org/mailman/listinfo/serusers
> >>    
> >>
> >
> >
> >  
> >




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