Satellite to VPN - slow transfer rate

[dcranford]

I know I'm abusing the hardware but we have installed satellite ISP services at off-site clinics. The data rate before the VPN connection was 384Kbps which is 'ok' for their needs. I installed a PIX 501 at the clinics (including the vpnclient commands) to establish a WAN link for my desktop users so they can access the LAN here on campus. The rate at the clinic desktops dropped to dial-up at best. Any suggestions? Deon Cranford
dc2@scotlandhealth.org

 

[svermill]

I have extensive satellite experience and no VPN experience. Questions such as yours have been coming up a lot over the last year, so I've poked my nose around a bit. The problem appears to be one of satellite latency and the apparently extensive handshaking that takes place with VPNs. You might find this interesting:

http://www.regulus-consulting.com/vpn.html

A search on yahoo or google will bring up lots of similar info.

 

[baddos]

It depends on your VPN... You are probably using 3DES encryption, which has a lot of overhead. You could try backing it down to regular DES and see if that helps. 3DES takes up more bandwidth than regular DES, but 3DES is way more secure.

 

[polarismd]

Is it the BT or Tiscali?

Firstly neither recommend that you do not do VPN due to the Latency. With the help of the groundstation we did get this to work but only when they temporarily switched us through a different network - they did it just to prove a point- that it can work.

Secondly if it is BT then you will have problems due to the restrictions on bandwidth experienced by all users. Upload is virtually non existent(this of course is required by VPN). You should complain to BT - need the address? Reply to this and we will give it to you.

We are trying to get some pressure on BT to give us what we all paid for.

Have you compared your speed to landline DSL? Its embarrassing.

 

[dcranford]

Rural areas in this part of NC barely have cablevision; much less DSL. &quot;Heck fire&quot;, ATM still stands for Adobe Type Manager down here. <grin> Believe me, satellite was our last resort. I'm curious about the 3DES that baddos mentioned. Most likely we are using that; I believe that was the default and I had no reason to change it. The satellite provider was OptiStream...can't fault them however; until the VPN was loaded into the PIX config, the satellite was perfect. Deon Cranford
dc2@scotlandhealth.org