As long as you have trunk access you should be fine.

On the i-series, Aspire, et al, I would make the trunk in it's own trunk group, then make a virtual extension call forward off prem using that trunk group.
With the CCIS you should be able to directly acces the trunks from either site.


[Linked Image from i26.servimg.com]
TouchPoint Networks.

Serving the Northwest Since 1991
NEC Shoretel Zultys T3 Tadiran