[cdl0002]

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. All of the remotes ping 40-100ms consistantly. The Contivity has the ability to run QoS (DiffServ, Bandwidth management, or Traffic shaping). Can you run DiffServ through an IPSec VPN tunnel end to end over the public Internet? Any suggestions or pitfalls that may happen with this scenario? Nortel says this will work with the setup we have but I wanted to know if anyone has tried it.

Thanks,
Clint

[ddaloia]

Originally Posted by cdl0002

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. All of the remotes ping 40-100ms consistantly. The Contivity has the ability to run QoS (DiffServ, Bandwidth management, or Traffic shaping). Can you run DiffServ through an IPSec VPN tunnel end to end over the public Internet? Any suggestions or pitfalls that may happen with this scenario? Nortel says this will work with the setup we have but I wanted to know if anyone has tried it. Thanks, Clint

yes and no.

you can enable QOS options on the sites. This will come in handy on forwarding the packets out of the routers (basically the packets will be sent first or bandwidth will be reserved, etc depending on how you configure your equiptment.) But the remote DSL locations packets are encapsulated once they leave your equiptment, meaning if you are added information to the headers of the packets, they will be ignored by internet routers. Dependning on the path that the routers take, if congestion lies on the network, your QOS will not do any good. The packets will be treated the same as any other data. Personally, I have gotten this to work in some locations, but some others do not work. Make sure you can use g729a codec so the calls are around 16K. G711 is much too large for DSL to handle. Good luck.