VPN Info

I hear the red bulb in his flat has blown and he's trying to fit a new one..
Seriouly though I hear he's been very busy lately but I'm sure he'll be back soon. This is a good thread, I'm waiting with interest for Sahir's pearls of wisdom too

this is most certainly interesting. i would also like to know if it would be possible (and i'm thinking that it is :roll: ) to tunnel voice packets thru a vpn and would there be any degradation in the quality of the voice being sent down the line? i'm also looking forward for the comments of the big S ....thanks..

this is a good thread! I'm looking at hsetting up a VPN to give a remote user(s) access to a small office network. Am i correct in thinking I need a VPN capable firewall at the office and then just some VPN client software on the remote PC?

Cheers

Basically, yes. At the office end you can use a firewall or a router with VPN capabilities. Or you can opt to host the VPN endpoint on a Microsoft server but personally I wouldn't go there. Known 'workers' are IPCop, Checkpoint Firewall-1 or the range of Draytek boxes. For the client end you just need some software - the native VPN support in Win XP for example

Hi guys,

I've sent Sahir a email regarding this thread since it seems quite a few people are expecting his response - which as usual is very informative and will surely cover you all.

I'd simply like to comment on the VPN/VoIP scenario brought forward by Jhun. It is possible to push VoIP packets through a VPN tunnel without much problem. I've managed to successfully setup a GRE Tunnel between two Cisco routers and have the two offices communicate with Cisco VoIP Phones.

The problem with any link is the latency, which should not exceed a specific point, otherwise you'll have jittering and lag effects which will make the conversation unbearable.

On the other hand, if your squeezing data at the same time, you'll need to implement some type of QoS. This can be done at the router level - in which case if you've got a VPN/GRE Tunnel, you'll need to use QoS Preclassification which classifies the packets before they enter the tunnel - or before the router with the use of some time of Firewall , e.g Linux.

In any case, keep in mind that the maximum acceptable latency in a VoIP session will vary depending on the codec used to compress the voice packets. Usually a maximum of upto 70-90 msec is bearable, but you should keep it under 50 to be on the safe side. I've come across implementations which would accept a latency upto 120-130 msec!

Cheers,

wow thanks Chris for the very informative reply. i was thinking of pushing data packets on the same link as my vpn tunnel would go through for the voice packets but since it would be bandwidth intensive (this would be used for a call center setup ) i'm thinking of making another connection for the internet access (like a dsl connection perhaps) leaving the other line (a T1) dedicated for voip. would something like this suffice?..i know that it is off topic and would like to make another thread regarding such setup if the mods would allow me to ..also if you could shed some light on how to setup a network fit for a call center i'm all ears especially for the voip part and how to make it secure without compromising the quality..again many thanks