Forum Discussion
John_Heyer_1508
Cirrostratus
CirrostratusHow do I enable the TCP Window Scaling option?
I've been doing some performance tests uploading and download large files over SSL with an F5 LTM in the middle. The virtual server setup is standard, using the default tcp profile.
In most per...
what version are you running? have you tried to increase send/receive buffer e.g. 65536 bytes?
Note: Beginning in 11.4.0, the window scale functionality is built into the TCP profile and cannot be manually disabled or enabled; it will be negotiated if the send or receive buffer is larger than 65535 bytes.sol7559: Overview of the TCP profile
https://support.f5.com/kb/en-us/solutions/public/7000/500/sol7559.html
nitass_89166
Noctilucent
Noctilucentwhat version are you running? have you tried to increase send/receive buffer e.g. 65536 bytes?
Note: Beginning in 11.4.0, the window scale functionality is built into the TCP profile and cannot be manually disabled or enabled; it will be negotiated if the send or receive buffer is larger than 65535 bytes.
sol7559: Overview of the TCP profile
https://support.f5.com/kb/en-us/solutions/public/7000/500/sol7559.html
John_Heyer_1508That's probably something to do with it. I had created a custom TCP profile in order to turn on Rate Pace (which significantly speed things up) and also set these per F5 recommendations: Proxy Buffer Low: 98304 bytes Proxy Buffer High: 131072 bytes Send and receive buffer are not changed though: Send Buffer: 65535 bytes Receive Window: 65535 bytes- John_Heyer_1508Ahhh so I set "Send Buffer" and "Receive Window" to match the Proxy Buffer High, now WSOPT is showing up in the packet captures and speeds are actually surpassing hitting the server directly
- John_Heyer_1508This is 11.5.1 HF6 btw