Bug ID 597369: Reopen TCP's receive window based on initial receive window size after a zero window

Last Modified: Sep 13, 2023

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

Known Affected Versions:
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, 12.1.2, 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, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6

Fixed In:
13.0.0

Opened: Jun 03, 2016

Severity: 3-Major

Symptoms

TCP reopens its receive window with 3*MSS bytes after a zero window, which is inefficient when round-trip time (RTT) is high.

Impact

Reopening receive window slowly on the receive side may impact the throughput performance of the sender on the other side.

Conditions

- TCP zero window is sent by BIG-IP. - TCP reopens receive window after enough data is drained from proxy.

Workaround

None.

Fix Information

TCP reopens it's receive window based on initial receive window size after a zero window episode.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips