1. SIP load balance solution???
External PSTN Calls -> PortaBilling (SIP Gateway) (203.10.x.x) -> Cisco SLB Load Balancer (210.15.x.x) -> Either CCM1 (172.16.55.5) OR CCM2
(172.16.55.6) -> User Agent
What we are looking for is simply a solution to load balance our external incoming PSTN calls and spread them across our two Cisco Call Manager servers. We need something INBETWEEN the sip gateway (portabilling) and the Cisco Call Manager servers to do the load balancing and pass the SIP packets correctly to the CCM's. We tried using Cisco SLB but this didn't work very well because the TO: field (URI) in the SIP header wasn't being changed to reflect the IP address of the CCM's (see capture below taken from the CCM end).
> INVITE sip:[email protected]:5060 SIP/2.0
> Via: SIP/2.0/UDP
> Max-Forwards: 70
> <sip:[email protected]>;tag=171a2a27c0d677b4b142551fa092f0f0
> To: <sip:[email protected]>
> Call-ID: [email protected]
> CSeq: 200 INVITE
> Contact: Anonymous <sip:203.10.x.x:5061>
> Expires: 300
> User-Agent: Sippy
Are there any cisco product or cisco config that might be able to do what we want inbetween the sip gateway and the CCM's???
2. Secondary IP / alias on CCM's???
Does the Cisco Call Manager support a secondry IP (aka ip aliasing / multihoming)? We woulnd't mind binding another secondary ip to the CCM servers to try and make SLB work w/o NAT.