Solved Multiple SIP trunks same Provider

[man416]

Is it possible to use have multiple SIP trunks using with the same provider and pointing to the same IP/server of the provider? Can it be done using IP based and multiple NICs.

We have a customer that wants to use a local provider not 3CX supported and has locations in several cities. We would like to use one system for all locations using 3 NICs, one for local network and phones, a second for SIP trunk 1 and a 3rd for SIP trunk 2. We have static routes built and the SIP trunks both work on inbound calls. The problem is when both trunks are setup the route will only allow it to go out one IP/connection. The provider delivers both trunks on their private network to a single connection but only allows one IP for us to point to for both SIP trunks.

Thanks

 

[Saqqara]

Are the sip trunks, username / password authenticated or ip authentication.

If username / password, you can use the same wan ip address. If IP then each sip connection will require a unique wan Ip address

Have a look at 3cx supported network setup https://www.3cx.com/blog/docs/network-configurations-supported-3cx-phone-system/

 

[man416]

thanks for the reply. It's currently setup as IP based but we may be able to switch to register/account.

 

[Saqqara]

If you have been assigned multiply wan ip addresses, you would do all the routing of the sip traffic using firewall rules & Nat so that each sip account will use a unique wan IP address just using one 3cx network card

 

[JohnS_3CX]

If you can convert to register based, it would be the most ideal scenario

https://www.3cx.com/docs/sip-trunk-inbound-calls/

 

[man416]

Since the trunks are being delivered on providers private network we aren't using a firewall. The firewall is only used for the local network side.

We did some testing using register based and I can't get it to register. According to the provider we are sending [email protected] which is the IP for their SIP server. They are telling me its rejecting because it has to be something other than their server address. I tried using the option "put public IP in SIP via Header" and using the IP they gave me to use but it doesn't change anything.

Do services need to be restarted when making changes to the SIP trunks/options?

 

[JohnS_3CX]

No they don't, as soon as you save them they will immediately apply and the trunk will try to register.

Since this is not a supported provider you can create a generic trunk and look through all the trunk options and parameters to adjust the trunk to something the provider accepts. You can use traces to see what the PBX sends and what the provider replies in real time and attempt yo build your own settings.

If on a windows server you can run wireshark live on it, if on a debian server you can run captures and restart the sip service to cause a hard re-registration.
https://www.3cx.com/docs/capture-network-traffic/

 

[man416]

Thanks for the replies. I was able to get both trunks working once we switched to Register/Account based and got that working.

 

[JohnS_3CX]

Glad to hear!