Different SIP Signaling and RTP addresses.

[ralph]

I need to bounce this off of Ya'll since I obviously don't understand.
Our SIP provider is telling us to use one IP address for signaling and another IP address for RTP.
For the life of me I can't figure out how the RTP address is entered in the system.
Can anyone give me a clue on how that works?

Ralph

[Dogbreath]

"Connection Information" fields in SIP/SDP message tells phone system where to send media to [and vice versa]. Basically - don't worry about it. So long as your firewall allows the traffic, it will work.

[x-man]

Its automatic as noted. basically it uses the Mitel for control IP and the local address of the phone for RTP via the main IP. That is as I understand it.

[ralph]

Thank you for your responses.
I thought that may be the answer but wasn't confident.
I'm so happy we have such depth of knowledge on this board.

Ralph

[eugenej]

Most ISP's here locally don't like that for a number of reasons.
If you absolutely must only send one IP for signalling and one for RTP then you could use an MBG as an anchor point for the phones (note single point of failure) OR if they want both signalling and RTP from the same address you need to use MBG as a SIP proxy.

[ralph]

I wish I could talk this customer into using SIP proxies.  It would make life so much easier.
They have multiple ingresses for their SIP trunks.
Networks in the US, HK and UK.
I'd have to admit that they've done pretty well with it using BGP but every once in a while I get a report of one way audio.
That's when I kick in to my mantra "One way audio is always network related".

Ralph

[acejavelin]

I wish I could talk this customer into using SIP proxies.  It would make life so much easier.
They have multiple ingresses for their SIP trunks.
Networks in the US, HK and UK.
I'd have to admit that they've done pretty well with it using BGP but every once in a while I get a report of one way audio.
That's when I kick in to my mantra "One way audio is always network related".

Ralph

Sounds like we have a similar customer... we have one with MBG's in the US, Ireland, and HK (and India but they have a PRI there), but even with MBG's we still get occasional reports of one-way audio. I use a similar mantra, and the other one "I can't fix the Internet"

[Dogbreath]

Most ISP's here locally don't like that for a number of reasons.
If you absolutely must only send one IP for signalling and one for RTP then you could use an MBG as an anchor point for the phones (note single point of failure) OR if they want both signalling and RTP from the same address you need to use MBG as a SIP proxy.

MCD just handles it - different IPs for media and signalling does not necessitate something extra to anchor the media.

[eugenej]

Most ISP's here locally don't like that for a number of reasons.
If you absolutely must only send one IP for signalling and one for RTP then you could use an MBG as an anchor point for the phones (note single point of failure) OR if they want both signalling and RTP from the same address you need to use MBG as a SIP proxy.

MCD just handles it - different IPs for media and signalling does not necessitate something extra to anchor the media.

MCD might handle it but the provider might not. All depends. Some ISP's will provide a single voice subnet (very small) and dedicated voice link and tell you they will only route traffic from those IP's. Otherwise you could end up NATing the media since the private ranges might overlap. We see that here all the time. Perhaps elsewhere on the globe they do it differently though

[x-man]

MCD handles both SIP providers I use. One is password authenticated and the other IP authenticated. Both work quite happily with no MBG. Unless someone cocks up the network then all bets are off.

[Dogbreath]

MCD might handle it but the provider might not. All depends. Some ISP's will provide a single voice subnet (very small) and dedicated voice link and tell you they will only route traffic from those IP's. Otherwise you could end up NATing the media since the private ranges might overlap. We see that here all the time. Perhaps elsewhere on the globe they do it differently though

I think we're answering different questions then - the OP was asking what to do when the provider offers different RTP and SIP IPs.