Very slow webbrowsing speed on some clients/browsers

Frequently Asked Questions
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Joined: 10 Apr 2008, 14:14
Location: Clavister HQ - Örnsköldsvik

Very slow webbrowsing speed on some clients/browsers

Post by Peter » 15 Jan 2010, 14:29

This FAQ applies to:
  • Clavister CorePlus™ 8.xx and 9.xx.
When browsing the web it goes extremely slow when i'm using the HTTP-ALG. Even downloading a small file takes a very long time.

Some applications are using a function called HTTP Pipelining, which is a technique in which multiple HTTP requests are written out to a single socket without waiting for the corresponding responses. This however causes problems due to how the HTTP-ALG handles HTTP requests, the result is that the performance and throughput will be very slow for the client.

The solution is to turn off pipelining in the browser. This option is not usually on per default as it needs to be manually enabled. Generally the support for HTTP Pipelining is not that common in network equipment.

To turn it off in In Firefox type "About:Config" in the address window to open the browser configuration where you can find this option.

Answer 2:
It might be packet loss on the internal network (between the Clavister and the Client) that causes this problem.
Look for duplex problems on all links (one NIC runs Full duplex and the other runs Half duplex).
Another typical way to see this, is that if you connect the client directly to the Clavister, it works, but if the client is moved behind some switches/routers, then this slowness appears again.

It might be on the Clavister's NIC towards the switch the problem is created, especially on the SG50 model, with the LAN/WAN interfaces (IXP chipset based NICs). You can try to use the DMZ/AUX instead, as they are based on a Realtek chipset and can set Link speed and Duplex, which the IXP chipset does not support.