You can find out this sort of thing by using the software advisor:
http://tools.cisco.com/Support/Fusion/FusionHome.do
The software advisor tells me that IS-IS is not supported on the 1751-V.
Assuming you are using V for Voice, for BGP you need the IP-VOICE-PLUS feature set in the Early Deployment train 12.2(15)T14, or IP-VOICE feature set in Early Deployment 12.3(2)T8. There are many other versions from other trains that support BGP.
Kevin Dorrell
Luxembourg
