SIP Failover

[liquidshokk]

Hi

A customer has asked if it is possible for their SIP lines to failover should their leased line failover to their backup ADSL line. I know we could connect to the system, change the IP address that the system goes out as and notify the SIP provider of the new address but is there a way to automate this? Maybe with two SIP lines? I'm guessing the address setting in the network topology tab would be the hurdle as it is IP authenticated? I suppose an option would be to have "run stun at startup" enabled and the system would just need rebooting to make it update address it goes out as? Admittedly we would still need to change the address at the SIP provider end unless we use password authentication.

Does anyone use the above or an alternative option?

 

[hairlessupportmonkey]

Surely their Leased line already has a backup xDSl attached to it and with the magic of BGP the traffic will route over that connection and the IP range will follow...

ACSS - SME
General Geek

 

[AvantiWade]

Depends how how their SIP Provider works and how the environment connects to the dual connections. If their SIP provider will only service sip through their leased circuit and not over the open internet then it won't work.

If they are setup with IP Auth and the provider will work on the open internet, you would just put both circuits public IP's into the authorized IP's section of the SIP providers portal. Then setup failover routing on their premise with a firewall or router. The phone system doesn't care what circuit its using, it just knows the call server IP address for the provider and to forward voice packets towards its own local default gateway. Its up to the default gateway to determine the path to use, that's where you need to build the redundancy.

 

[mforrence]

The phone system doesn't care what circuit its using, it just knows the call server IP address for the provider and to forward voice packets towards its own local default gateway.

There is usually more to it, as the IPO needs to include its own public IP address in the SIP setup packets. So, unless you have a proxy on site or a working ALG/fixup that will modify the SIP packets with the public IP address that is in use, there may be a challenge.

That said, I'm interested in other strategies for this.

 

[liquidshokk]

Thanks for all the info,

Hairlesssupportmonkey, their IT Co have confirmed the IP address will change when the Internet fails over so I'm guessing it must be a completely separate line to the leased line setup. It's shared of offices, which may have something to do with it.

I will check if the SIP provider can authenticate on multiple IPs. I'm pretty sure it's only one on Gamma and voiceflex. ..

I know in the past the SIP won't work unless the correct external IP is shown in network topology tab.

I will check if the IT provider can set things up so that the same external IP is used regardless of line state but not sure this will be possible...

Thanks

 

[amriddle01]

This is where registered trunks win out, wouldn't be an issue