MX64 NAT and SIP, with load balancing

[Rolando]

I am currently working in a implementation of a MX64 in a call center with load balancing of two diferent internet providers.

The thing is, we have two asterix pbx servers working on and one router behind the MX64. The router has all the LAN of agents behind it.

The MX64 must do the NAT forwarding for the pbx servers that received the calls from another big call center, and of course the calls must be forwarded from the servers to the router where is the agents lans. The thing is the calls are not being forwarded.

We conected the servers direct to the internet like it was before, and just the router with the agents lan behing de MX64 and all agents conected just by one Internet provider, after that the agents couldn't hear the calls that was being forwarded. One thing i could notince is that the router has activated the SIP ALG protocol.

Any clue how can i solved this problem?.

[PhilipDAth]

I can't conceptualise your network in my head.  Could you do a diagram?

[Rolando]

Ok, i hope this helps

[PhilipDAth]

If you disable the SIP ALG does it make any difference?

Personally I get phones to use TLS when registering with a SIP serving in this kind of scenario.  That is because the encryption prevents devices in the middle seeing what is happening and attempting to do tricky things.

Perhaps we need to break the problem down further.  If plug plug a phone directly into the MX64 does it work?  If it does, we know it is an issue with the other other.  If it doesn't work then it is an issue with the MX64 configuration (such as not enough ports being NATed through).,

[Rolando]

I dindt try it, because the call center is working almost all day, and after the working hours there is no calls forwarded from the big call center.

But ill prepare a laboratory simulating this scenario, and ill try the things that you say.

Thanks ill bring knews.