ckleea

要看你想點用？

If you use load balancing, you can use as usual but careful about the registration of sip trunk like HKBN2b account

If you use fail over, it would be more complicated and I have no idea right now
I believe, you need to use externhost instead of externip in sip.conf to avoid problems

There are also other ways to play with multiple wans. In my case, I can map one external ip to one asterisk or ATA device such as OBi...

ckleea

Depend on the mode you choose. You can use either load balancing or failover. But you need to plan for what you want. Sometimes, you may want a mixture.