Is it feasible to run VoIP through an IPSec VPN that is traversing the public network? We have a Nortel Contivity 1100 switch at our corporate office with Contivity 1050s at our remote home users. We have a full data T1 at corporate and the remotes are using 768/128 DSL. The Contivity has the ability to run QoS (DiffServ, Bandwidth management, or Traffic shaping). Can you run DiffServ through a VPN tunnel end to end over the public Internet? Any suggestions or pitfalls that may happen with this scenario?