---
title: backend.socket.tcpi_rcv_rtt
summary: null
url: >-
  https://www.fastly.com/documentation/reference/vcl/variables/backend-connection/backend-socket-tcpi-rcv-rtt
---

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

**Available in:** fetch

Receiver-side estimation of TCP round-trip time (RTT) for the backend connection.