Bug ID 643041: Less than optimal interaction between OneConnect and proxy MSS

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.2.1, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2, 12.1.0, 12.1.1, 12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5

Fixed In:
13.1.0, 13.0.1, 12.1.5.1

Opened: Feb 03, 2017

Severity: 3-Major

Related Article: K64451315

Symptoms

When a client with low MSS is the first to establish a OneConnect flow pair and proxy MSS is enabled, the serverside will share the same low MSS. Successive connections from full-MSS clients may utilize this server-side flow, resulting in suboptimal throughput.

Impact

Decreased throughput, possible congestion due to small segments.

Conditions

Configure a virtual server with both OneConnect and proxy MSS. Note: Proxy MSS is enabled by default beginning with v12.1.0.

Workaround

In some instances, it may be sufficient to disable proxy MSS. This too has the potential to increase segment count and decrease throughput.

Fix Information

This release provides improved interaction between OneConnect and proxy MSS. By default, proxy MSS is disabled with OneConnect. This is controlled by the db variable TM.Tcp.OC.ProxyMSS

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips