---
title: client.socket.tcpi_pacing_rate
summary: null
url: >-
  https://www.fastly.com/documentation/reference/vcl/variables/client-connection/client-socket-tcpi-pacing-rate
---

**Type:** INTEGER  
**Access:** read-only

**Available in:** recv, deliver, log, error

The rate, expressed in bytes per second, at which the fair
queuing queuing discipline (a.k.a., fq qdisc) - used as a default by
Fastly - will attempt to evenly send data to the client when not restricted by 
either the congestion window or the availability of application data. It
changes throughout the lifetime of the connection based on the current
size of the congestion window and the current round trip time
estimate.

Fair queuing seeks to use a pacing rate a bit higher than is necessary to
transmit one window of data in one round trip. Pacing reduces on-path
buffering. The rate includes all packet transmissions including TCP
and IP overhead as well as acknowledgments and retransmissions.