Dual WAN with VoIP

[simorix]

Hi all,

I want to try OPNSense in a setup with VoIP.
We have 2 WAN's: adsl and 4G.
I want all VoIP traffic through the adsl line and all other traffic over 4G, except during a failover.
Is this possible?

[muchacha_grande]

Hi,
it is possible.
I made the same configuration for a customer, just with a difference.
In my case, I used dual WAN balanced for the general traffic, and for the SIP traffic, the second WAN as main connection that, in case of failure, it switches to the first WAN.
When you have dual WAN you may define more than one gateway group.
One for load balance, one for failover to the second WAN and a third for failover to the first one.
Then you use policy routing to redirect each kind of traffic to the desired gateway group.

These are the gateway groups to define

LOAD BALANCE
WAN1  ->  TIER 1
WAN2  ->  TIER 1

FAILOVER 1
WAN1  ->  TIER 1
WAN2  ->  TIER 2

FAILOVER 2
WAN1  ->  TIER 2
WAN2  ->  TIER 1

And in the LAN firewall rules you need at least two rules to select the gateway group needed for SIP traffic and the rest.

rule 1 ->  source address (IP of the SIP device or PBX), destination address (ANY), gateway (FAILOVER 1)
rule 2 ->  source address (ANY), destination address (ANY), gateway (FAILOVER 2)

Note that the order of the rules are important because the first rule catches the SIP traffic and the second catches ALL the traffic, so you must evaluate the SIP traffic first and then the rest.

Hope you get it working,
Cheers....


PD: this is then link from where I got the info https://docs.opnsense.org/manual/how-tos/multiwan.html