I've been trying (unsuccessfully) to use a 3.7 with VOIP trunks configured as SIP to tie into a BCM50 R2 with SIP trunks & MCDN keycode. I'm going to upgrade the 3.7 to 4.0 and I wanted to know if I'm right that SIP trunks are cheaper and can only be used as SIP trunks, and VOIP trunks can be configured as either SIP or H323? If VOIP trunk keycodes, and MCDN keycodes are used and it's configured as SIP, will the private rec'd digits work on 4.0 as they definitely didn't on 3.7?