I have a CallManager cluster version 8.6.2 with two Gateways 2901. Each Gateway has two PRI E1 (one card VWIC3-2MFT-T1/E1), one card with 64 DSP (PVDM3-64) and one card with 32 DSP (PVDM3-32). I also have a Cisco IP Phone 9971. Can I make video conf...