We have a main office using Avaya IP office (SIP trunk supported) installed. Now, we have a new branch in another country. We would like to forward the incoming call from analog telephone line at the new branch to our Avaya IP office in the main office.
My question is what hardware I need at the new branch in this situation for forwarding the analog call from our new branch to the main main office via SIP. For option 1, digium VoIP gateway G100. For option 2, install AsteriskNOW and configured as a VoIP gateway. In option 2, what hardware do I really need, e.g. PXS card?
Do we need fixed IP addresses on both sites? Or we just need a fixed IP address in the main office?
Hope anyone could help to answer and explain. Thanks in advance.