Slow Application response behind PPTP tunnel?

rameezk_1999 · ‎01-11-2009

Dear Support team,

We have configured cisco 2821 as PPTP server and we have users at remote location dial-ing VPN PPTP tunnel over VSAT connect. The latency is between 1 to 2 seconds as it is usual in VSAT links.

The remote users are able to establish PPTP tunnel and also able to ping my router and Application server on the LAN. But the users are facing very slow application response time.

We are running the same scenario over Nortel Router but the Application response time is good for remote users.

But we need to migrate this solution to Cisco Router as soon as we can because the Nortel Router is hangs after few hours..

Please try to respond at your earliest

Ivan Martinon · ‎01-12-2009

I would go and play around a little bit with MTU and MSS settings, since any kind of VPN connection/encapsulation will add extra overhead to the original packet causing some traffic to be fragmented with no reason.

Go ahead and try to reduce the ip mtu and tcp mss on the interface where the application servers are, for example: ip mtu 1400 and ip tcp mss 1300, see if that speeds up things a little

rameezk_1999 · ‎01-13-2009

Dear Imartino,

Thanks for your response..

Let me give you a breif idea of our network.

Actually, remote users dial-in PPTP session to a Test Cisco Router in my network. To reach the application server from this router, i have to hop two cisco routers in my LAN in order to reach it.

So now, please tell me that where should i put these commands and on which interfaces?

Do i have to add these commands to the interface of the router taking towards the application server?

Or do i have to add it also on two routers coming in the path towards the application server? on these two routers, shall i put the commands on both incoming and out going interface going towards the application server?

Please advice??

Ivan Martinon · ‎01-13-2009

Those commands could be placed on the router facing the application server, or on the interface where this pptp router is, facing the LAN and not the WAN.