we are currently using nortel 1140E ip phones and it's working fine when connecting to our 3750G switch. we are migrating to use the cisco 7941 ip phones and our testing failed. the 3750G switch is correctly configured for voice vlan, ospf routing and connecting to the nortel call server. per tshooting, i can ping our DHCP server and cisco call manager IP addresses from source voice vlan. the cisco ip phone is stuck in getting DHCP ip address. was wondering why it worked for nortel but not for cisco. please enlighten.