I am still a newbie in the VOIP industry, and i am pursuing an idea that i have, i am not sure if it is applicable or not though, perhaps you experts can better assist me.
Scenario:
In our Head office, we have a panasonic IP PBX system, connected with 2 external phone lines. We have a DSL internet connection with dynamic IP address.
And then, we have our construction site offices, let us say 1 site office for now. We have an internet connection at this site office using the 3G routers which also has dynamic IP address.
What i want to do is the following:
Install 1 IP phone set in this site office, which via the 3G router can connect to our head office VOIP PBX, so we can reach this site office as an extension. Also this site office can access our phone lines to make external calls.
Of course, both our head office and site office modem routers have dynamic dns capabilities.
So what do you think, is my idea do-able? what kind of hardware/software do we need from asterisk or digium in order to achieve this?
Even with dynamic DNS, you still need a stable IP address, as Asterisk will only look it up when starting. Quite a few, mainly consumer oriented, ISPs appear to deliberately produce unstable addresses, possibly to discourage the user of servers.
It would push the problem of dynamic IP onto the VPN software. It would be desirable anyway, because it would allow you to firewall out the rest of the world from the VoIP system
You asked on an Asterisk forum, but on re-reading, it is not clear that you need Asterisk.
Apart, possibly, from something more VoIP friendly than a 3G router, and the phone itself, you may not need any additional hardware, but that depends on the capabilities of the existing PABX.