[Asterisk-Users] call routing on free trunk ??

[Paco Perez]

Hello:

I would like to know if it's possible to route a call based on a free trunk.

Let's say we got 5 o 6 locations with 4 analog lines and asterisk and Digium 
hardware on each.

We got 10 sip phones ( or IAX ) on each location.

We got an sdsl 400 Kbps with the same Internet provider, with good perfomance 
on their own network.

We have done all the IP QOS stuff (we got internet cafe too)

And when the user dial a number we do an LCR preasignation (adding 1050 e.g. 
in front of the string dialed) depending on prefix (LCDial e.g.).

At this moment how can I route the call to a free analog on a remote asterisk 
line if I got the 4 full lines at this location ??

Is it by dialplan ??

Do I need to register all trunks on all servers or can I do centralized ??

If the call is transfered. where will be the CDRs produced ??

Thanks