Performance of LTM3400

My $0.02:

 

1) Why does the server perform at only 2.69Mbps to begin with? Seems pretty slow, even for dynamic content.

 

2) As for BIG-IP changing the performance, I'd want to highlight a few things:

 

- Was the first test directly to the server on the same LAN segment? I've observed that some TCP stacks have different TCP behavior when communicating with hosts on the same LAN segment vs. going through it's default gateway. i.e. the server may be changing it's behavior and causing the change in performance, not directly BIG-IP.

 

- BIG-IP's default settings are probably best suited for a reasonably fast WAN. To get ideal performance in a LAN, using FastL4 or a modified TCP profile may be required. To get ideal performance on a not-so-nice WAN, a modifying the TCP profile may also be necessary.

 

- If the customers test simulates the expected use case when the product is deployed (i.e. appropriate client bandwidth, representative application access pattern, etc), it probably makes sense to do additional testing and figure out what's going on. However, if this test isn't representative of the expected use case (latency, bandwidth, access pattern, number of concurrent users, etc), then I'd probably try to look past this one test for the time being. It's not uncommon that performance may vary slightly in a small/isolated test, but it would be a big surprise if BIG-IP negatively impacted performance in a real deployment.

 

 

Good luck!