[HELP] E1 gateway

Customer has two locations. The first one is an isolated & unattended facility where E1 lines are connected to PSTN. The second one is a building where all the extensions and support staff are located.

Those two buildings are several miles away and connected via IP with enough bandwith to bear VoIP traffic. There’s no way to move the E1 lines to second building.

We are planning to implement Asterisk in 2nd location (with all the dialplan & IVR configuration) and somehow ‘encapsulate’ those E1 lines to arrive from 1st building. We know that we can make a solution with Cisco routers but the cost of E1 adapters is prohibitive.

So, we also plan to implement an Asterisk gateway in 1st building with Digium 4xE1 adapter and somehow connect those two. As 1st building infrastructure runs unattended, we need it with minimal configuration.

Now the question is what’s the smartest way to configure this?

Thanks in advance.