I've got a client looking to use an NBX 3102 handset at her home office and currently they have no routers capable of passing multicast over a VPN. The phone uses multicast for button indicator lights and without having the ability to pass the traffic the handset won't be much use to her. My question is what is the best Cisco router hardware to go with to implement a VPN supporting multicast? I've seen where it's possible to use it over a GRE tunnel I'm just not sure which model series would be the most cost effective for a small office user. The office only has one DSL internet connection coming in with a block of (5) public IP addresses. The home office is using cable internet with (1) static IP address. I'm aware QoS will be poor with UDP packets across different service providers but for only one remote handset it should be sufficient. Which model would be appropriate for this installation? Thanks!