VPN bandwidth limited

As far as I understand it, when a VPN is setup, either through 2 VPN routers, or through a Windows server and an XP workstation, the Internet connection for that workstation is limited by the upload bandwidth of the place your are VPN'ed into. Or is it that case that any one who uses that Internet connection where the client workstation is, is now limited by the upload bandwidth of the place they are VPNing into.
Please let me know if this is correct. We want to setup a VPN for someone to a Windows serever but we do not want to limit their bandwidth while they are connected.
Would 2 NIC's help?

 

The limiting factor in any VPN over internet would always be the speed - both download and upload. If you are using synchronous connection your download speed ~ upload speed but in any asynchronous connection, download speed > upload speed. Best to use synchronous connection if you can.

 

The client location has cable broadband, and the server has sync DSL.
How do I change these settings that you are suggestion?

 

What kind of cable broadband is at the client location and where are you moving the data from? If you are moving data from server to client, there would be no problem but if you are moving data from client to server, it could be a problem as normally cable broadband is asynchronous - download speed > upload speed.

 

what about client to other location while still in the VPN.

 

Don't confuse VPN with bandwidth or download/upload speed. VPN is a technology to transfer your data securely over open public networks. Since it relies on the underlying network for data transfer, the speed is determined by your internet connection. SInce VPN has to encrypt/decrypt data at both the ends the throughput you would get thru VPN is slightly less than normal internet thruput, otherwise treat VPN connection as a normal internet connection and expect the same speeds.

 

So, if I have a VPN connected. Then i surf the web, or download files, I will get almost the same bandwith as if I was not connected? What if the place i am VPNing into has a much slower connection that I do, wont my DNS still have to go through the VPN before it hits the Internet?

 

If you have an active VPN connection and download/surf at the same time, you would get less thruput in both the cases as you are using the same bandwidth to transfer both at the same time. Depends on how critical is your VPN connection bandwidth.

DNS has no major role to play in VPN as its point to point & you would be knowing IP addresses at both the ends before being able to set up a VPN.

 

It is worth pointing out that most decent VPN clients will block independant browsing while the VPN connection is in place. If they don't do that, each VPN connection becomes a wide open hole through the firewall. That is, there is an unfiltered path from the internet to the internal network via the VPN connection.

The simpliest way to block this hole, and the one usually in place, is to force the internet traffic through the VPN connection. So while the VPN client is active, the user's internet requests are passed through the VPN and are then routed via the internal network. This means that if the VPN connection at the server end, is not given a route to the internet (preferably through the firewall), internet access stops while the client VPN is running.

Therefore, for a decent system, accessing the internet while the VPN connection is open will use up VPN bandwidth.