Forum Discussion
David_Sherman_2
Nimbostratus
NimbostratusTCP profile - client and server
I have read through this forum topic with great interest. I found several messages that dealt with tcp profile optimization. I have one question though.
When configuring a TCP profile, there is an option to select "Protocol Profile (Client)" and "Protocol Profile (Server)". The default is "TCP" as the client profile and "(Use Client Profile)" as the server profile.
If configuring a VIP that will front end a pool of high end web servers that will be accessed from the Internet, should the "Protocol Profile (Client)" be set to the "tcp-wan-optimized" profile and the Protocol Profile (Server) be set to "tcp-lan-optimized" profile? At least as a start?
- JRahm
Admin
I would think so intuitively, and this is the direction I received a few years ago from F5 support. However, in recent months, our ops team has received direction that the client profile in a WAN environment should be carried through to the server. Best advice is to test,test,test. 
David_Sherman_2Thanks for the info. It is really helpful. I wish though, that the F5 developers would step up and give some guidance on this. The TCP Express capabilities are prominently advertised, however, I find that configuration recommendations are lacking. It would be very helpful if the developers would say, "If your web servers are high performance (I'm using IBM P590), and your clients all connect on high speed LAN connections, then generally best performance would be the LAN protocol to both client and to server. If the clients are on slower links or on the internet, then generally, best performance would be with WAN optimized on client and LAN optimized on server.
Perhaps the recommendation would be to use L4 and utilize the PVA and forgo F5 SSL termination would be best, if the servers are up to the task.
James_ThomsonEmployee
The performance of your web server doesn't matter necessarily. The conditions of the LAN are what matter. So, if you are on a local segment, use the TCP-Lan-optimized for the server-side and the WAN-optimized for the client-side.
If you have a high performance server in Hong Kong and your BIG-IP in London and you're accessing it over an internet link, then you'd want to use the wan-optimized in that case.
Using FastL4 and not taking advantage of the dual tcp stacks just means that your "High Powered Server" is going to have to use the least common TCP options that each client supports individually and will need to negotiate different tcp options for each client. So, if some clients are coming in with windows 2000 on a dial-up connection, then your server will spend resources lowering window sizes, dropping packets and being inefficient.
With the LTM full proxy in line, your server will always get optimal tcp options from a tcp-wan-optimized profile on the server-side of the BIG-IP LTM and the clients each get handled as best they can with the wan-optimized.
