Bug ID 949721: QUIC does not send control frames in PTO packets

Last Modified: Sep 13, 2023

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

Known Affected Versions:,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4, 16.0.0,, 16.0.1,

Fixed In:

Opened: Sep 29, 2020

Severity: 4-Minor


When the QUIC PTO timer fires, it may resend some in-flight data. That data will not include any in-flight control frames.


Minimal. The PTO timer is a mechanism to 'get ahead' of any lost packets and if a packet containing control frames is lost, those frames will be retransmitted.


A control frame is in-flight when the PTO timer fires.



Fix Information

Retransmittable control frames are now sent when the PTO timer fires.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips