vpn usable with dial-up line or not

[ykfc]

I don’t have previous vpn experience at all. I've got broadband connection but for some reasons I could only start testin my vpn connectivity to the server via dial-up internet.

My WindowsXp vpn client has firewall turned on but exceptions are all allowed for file sharing, remote desktop and upnp framework etc.

Employing standard pptp the connection could be established fine every time. When I run a variety of applications such as pcanywhere, remote desktop, or citrix client, all applications start normally but they all look freezed after a very short while. Often the application received a terminating message.

The various error messages I received were:
1) when connected as a Citrix client.
message was: Metafram presentation server is interrupted
2) when connecting to a remote terminal server with remote desktop. The message was:connection to remote computer was broken.

Note: VPN connection remained maintained when those error messages popped up.

Then I ran simple tests with file copy from the remote machine to my local disk. Browsing remote folders seems to work at all times. If I copy a small file (a few k), it seems always working too. But I had never had a success to copy a file that is more than a few hundreds k, I received the error: “cannot copy myfilename.xxx, the specified network name is no longer available”. I do not know what additional firewall parameters or network settings I could manipulate. I tried but in vain.

Then I disabled the WindowsXp firewall. File copying works ok now for a few hundred Kb size. I am not sure if those performance figure looks normal at all. Copying say a 700Kb file took me 3-4 minutes. In other words, 1 kb took more than 3 seconds!! Sounds silly to me. Internet webpage browsing speed looks quite normal and I believe it is up to standard with a normal 56kbps service.

Much appreciated for any comments received from the experienced.

 

[ykfc]

Ok. I found out I need to disable firewall totally to make remote desktop to work normall. Isn't it a must to have with all VPN connection?

 

[ykfc]

I'm still waiting for comments/answers. When I wrote (remote desktop) works normally I meant the error message "connection to remote computer was broken" is not appearing again. The response is still far from satisfactory. I always need to wait one minute before a new dialog box was brought up after mouse click. But why? Are we recommended to enable Windows Firewall?

Also, I wish to get explanation why small file copy works but not for slightly larger file.

 

[steveroot]

ykfc said "I don’t have previous vpn experience at all. I've got broadband connection but for some reasons I could only start testin my vpn connectivity to the server via dial-up internet."

Not sure I follow correctly. A VPN looks like this.

Site A > [VPN over internet] < Site B

So to test your VPN end at site A (your Broadband) you need to go to site B to test. Using dial up to the internet is often the simplest way to test, as you can be at Site A one computer while being at Site B on another computer while still being on one desk.

As for speed, dial up is slow, VPN makes it slower. The file has to be encrypted, then decrypted and this generates extra data that has to be sent. How much slower I couldn't tell you. I found windows file share very slow compared to FTP transfer from the same server to the same client over the same VPN connection - but that just could be how my office is set up.

As for losing the connection - is your Site A on a dynamic IP address? Might be worth seeing if the IP address changed which is breaking your VPN connection (pure guess - I have static IP so wouldn't know how dynamic affects it).

ykfc said "Isn't it [firewall] a must to have with all VPN connection?"
Yes and No
Yes, it is good to have a firewall on an internet connection as you cannot trust everyone else on the internet.
No, you don't need to firewall your VPN connection *IF* you trust everyone on the network you have VPN'd too. A bit like firewalling your network connection in the office network.
It's no good firewalling a service you want to connect to (that is, if your server is firewalled you may not be able to connect to it), as for your client connection, you can firewall it if you know that you don't want anyone else to connect to your computer (eg you are not sharing files).

HTH
Steve

--
Steve Root

http://www.rootskitchens.co.uk

 

[ykfc]

Thanks Steve for taking effort and pass your experience. You wrote:"So to test your VPN end at site A (your Broadband) you need to go to site B to test."

Maybe you missed my point, maybe not. I am simply having a Notebook at home, trying to vpn to the office. At home I can connect to the Internet via broadband or via dial-up Internet connection. Long story about why I am not using broadband but trying to run vpn over dial-up line.

Is there an explanation for the need to disable firewall in my notebook (that runs WinXP) before I am able to work normally (though slow) with other computers in the office?

 

[ykfc]

May need to mention: the vpn server sits in the office.The ISP allocates a dynamic IP to my notebook (as it is a low-cost dial-up Internet service)