Bug ID 617307: FastL4 with full PVA acceleration: Average connections per second decreased 5-7% since v12.1.1 on i5800 platforms

Last Modified: Jul 12, 2023

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
12.1.2, 12.1.1

Fixed In:

Opened: Sep 16, 2016

Severity: 3-Major


Custom BIG-IP hardware provides a significant assist to the main CPU complex for FastL4 traffic with full PVA acceleration enabled; however, the main CPU still performs significant per-connection packet processing. Bug fixes and stability improvements in v12.1.1-HF1 and -HF2 have increased this load slightly. With a traffic profile that results in a high number of new connections and very little data exchanged per connection, if the CPU reaches 100% utilization, the average connections per second will be decreased.


The average CPS will decrease over the same configuration running v12.1.1 by approximately 5 percent, as observed with internal F5 traffic stress testing.


BIG-IP v12.1.1_HF1 and _HF2, with a virtual server configured for FastL4 traffic, and including a profile that enables Full PVA Acceleration is affected. The traffic includes an extreme number of new connections, with minimal data exchanged during each connection. i5800 appliances have shown a 5-7% decrease.



Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips