I am in the process of designing a VoIP WAN network - 30 Cisco 1601 routers as access and 3 core cisco 3640's - I will be using VG200's on all sites with NM-2v and FXS. What QoS configurations can I apply on the 1600's and to what IOS must I upgrade to - this is the first phase , second phase will be to move to IPT. Is it an option for me to replace all the 1600's with 1751-V/1760-V becoause of the VOX software for IPT? It is more cost effective NOW because the VG200 is a lot cheaper than replacing all the routers with 1700's (WIC-1T etc).Please help