Cisco Any connect VPN issue.

[shashanksgr251]

We are using Cisco any connect VPN and when are trying to copy a data over VPN we are facing dead slowness. For example, If we copy 1-2 GB file from server to machine/laptop over VPN from remote site we are getting 30Kbps speed. Our bandwidth at both the end is very good and that's not a bottle neck. As a remote team, need to rely upon this connection through VPN and will need it to be more responsive.

Just wanted to check if any configuration need to verify at Cisco ASA to improve the speed over VPN. Could you please advise any suggestion to boost VPN speed and what is the limitation.

Cisco ASA : ASA5555

ASA Version: 9.6(2)7

Any connect Version : Version 4.4

Thanks in advance. 

[Philip D'Ath]

This is often an MTU issue, or an issue with asymmetric circuits.

What OS is your machine, and what OS is the server you are connecting to?

[shashanksgr251]

Thanks Philip.

We have tried with Windows 7/8/10 as well as IOS at client side.Destination is shared file server and runs on windows server 2012 R2.  

To isolate the asymmetric circuit we have tested copying with different ISP at client side.  

But i am more interested to know if any ASA configurations will impact the VPN performance. ? 

[Philip D'Ath]

The ASA configuration itself doesn't usually affect the performance, as long as the MTUs are correct.

A lot of the time when I have issued like this it is because the Windows TCP stack needed tuning.  From an administrator command prompt, ideally on both the server and the Windows client, try:

netsh int tcp set global timestamps=enable