Thanks for the replies.

We may invest in an extra IP phone, as that sounds like the simplest option.

MacGyver- I was wondering if there was an option via DISA, but hadn't heard of a 'service observing unit.' We're a fairly small call center, and even if only able to monitor trunks it could still be an option - we're lucky to have 5-6 simultaneous incoming calls into the call center after hours, thus only a handful of trunks to need to plug into.

Thanks again.