Primary link between HQ & BO is 1Gig with OSPF as routing protocol(utilization is very less though). We have Avaya 4625 Ip phones at BO and talk/regester with server at HQ. So incase if the gig link has issues , is it better idea to route Voice/ip phone traffic via VPN tunnel (for data, its fine). Has anybody ever put this scenario in production...? and does it need any fine tuning from Avaya servers end or Cisco gear end...? Please suggest.