[clug] VPN over Wireless

Stephen Hodgman steve at namsys.com.au
Thu Jan 17 22:45:36 GMT 2008

Hello All,
I am having some difficulties running VPNs over wireless links and 
wanted to know if anyone can offer help please.

I am using WinXP clients making a PPTP connection over Telstra NextG 
wireless and ADSL links  to a Snapgear Firewall box.  The Snapgear is an 
embedded Linux unit that offers simple VPN/Firewall  services.  What I 
am finding is that the XP clients connecting via ADSL get very good 
connection times.  Over wireless though it is terrible.

I have recently trialled Netspeed's Longreach Wireless as an alternative 
and had similar difficulties.  On this I have tried decreasing the MTU 
and found it does improve the service but it is still not real good.

What I was interested in was anyone else's experience and/or some 
explanation as to why the wireless links should be so temperamental.  I 
would have thought the VPN was just a TCP connection and it should 
handle traffic as normal.  e.g. On the Netspeed link, I can do sustained 
FTP downloads and have no difficulties.  If it do an "ls -lRt" on a 
terminal session over the VPN on wireless it clags and kills the link 
almost immediately.  What is the difference?  I see there would be some 
"vpn padding" around the data but it must be very susceptible to timing 

Anyway, if anyone can offer suggestions on how to improve the link I 
would be most grateful.  I am stuck with the client systems and 
protocols for now so I would like to really make the best of it.

Stephen Hodgman
Namadgi Systems
+61 (0)407 182 355 (mobile)
+61 (0)2 6285 3460 (Office)
+61 (0)2 6285 3459 (Fax)

More information about the linux mailing list