ltm rule command TCP rtt
iRule(1) BIG-IP TMSH Manual iRule(1)
TCP::rtt
Returns the smoothed round-trip time estimate for a TCP connection.
SYNOPSIS
TCP::rtt
DESCRIPTION
Returns the smoothed round-trip time estimate for a TCP connection.
Syntax
TCP::rtt
* Returns the smoothed round-trip time estimate for a TCP connection.
Note that the value returned is in units of "1/32 of a millisecond".
(Divide the returned value by 32 to get the actual round trip time in milliseconds.)
Note that the rtt takes some time to converge, so we recommend using ROUTE::rttvar
to get the statistical variance of rtt in 1/16 ms intervals & cull outliers.
RETURN VALUE
VALID DURING
CLIENT_ACCEPTED, CLIENT_CLOSED, CLIENT_DATA, SERVER_CLOSED, SERVER_CONNECTED, SERVER_DATA, SIP_REQUEST,
SIP_REQUEST_SEND, SIP_RESPONSE, STREAM_MATCHED
EXAMPLES
when HTTP_RESPONSE {
clientside { set rtt [TCP::rtt] }
if {$rtt < 1600 } {
log "NOcompress rtt=$rtt"
COMPRESS::disable
}
else {
log "compress rtt=$rtt"
COMPRESS::enable
COMPRESS::gzip level 9
}
}
HINTS
SEE ALSO
CHANGE LOG
@BIGIP-9.0.0 --First introduced the command.
BIG-IP 2020-06-23 iRule(1)