P_LATENCYMODE

code: 128

# set
<module-index>/<port-index> P_LATENCYMODE <mode>

# get
<module-index>/<port-index> P_LATENCYMODE ?

Description

Latency is measured by inserting a time-stamp in each packet when it is transmitted, and relating it to the time when the packet is received. There are four separate modes for calculating the latency:

  • Last-bit-out to last-bit-in, which measures basic bit-transit time, independent of packet length.

  • First-bit-out to last-bit-in, which adds the time taken to transmit the packet itself.

  • Last-bit-out to first-bit-in, which subtracts the time taken to transmit the packet itself. The same latency mode must be configured for the transmitting port and the receiving port; otherwise invalid measurements will occur.

  • First-bit-out to first-bit-in, which adds the time taken to transmit the packet itself, and subtracts the time taken to transmit the packet itself. The same latency mode must be configured for the transmitting port and the receiving port; otherwise invalid measurements will occur.

Actions

set, get

Parameters

  1. mode: byte, the latency measurement mode of the port

  • LAST2LAST = 0

  • FIRST2LAST = 1

  • LAST2FIRST = 2

  • FIRST2FIRST = 3

Example

# set
input:  0/1 P_LATENCYMODE LAST2LAST
output: <OK>

# get
input:  0/1 P_LATENCYMODE ?
output: 0/1 P_LATENCYMODE LAST2LAST