philpete,
You pointed some some very good points and as a certified ShoreTel tech I would caution those looking to run a SIP trunk to a ShoreTel system to really do their research! I have been playing with this stuff a lot lately and a lot of key features of the ShoreTel system are turned off with a SIP trunk. ShoreTel really is on the right track with their product and the new 6.1 features will enchance SIP trunking a little more. In our office we currently have our ShoreTel system working through our Call Manager system via SIP trunk and there are some limitations, but it works and both Cisco and ShoreTel told me it wouldn't!
