latency
latency
The latency tool is used to inspect packets sent via pktgen with time stamp injection applied. The tool calculates the round trip latency from when the packets are transmitted until they are received.For 3GA, only ports running with the traffic generator profile can be used.
- Note
- The link speed
-l
, the timestamp method-t
and the timestamp offset inject mode-i
must match the values used by pktgen on the transmitting server. The values to use are displayed by pktgen. The-t
and-i
options must only be used if they are displayed by pktgen.
Syntax
latency -p -r -u -l [-i] [-t] [--help]
Command | Description |
---|---|
--help , -h | Displays the help |
-p <port> | The port to inspect |
-r <secs> | Reset interval - how often should statistics be reset |
-u <secs> | How often should the screen be updated |
-l <speed> | Link speed of the port used by pktgen is in Mbps. Supported speeds: 10, 100, 1000, 10000, 40000 |
-t <timestamp method> | Timestamp method of the port used by pktgen. Supported values: SOF, EOF |
-i <inject mode> | Timestamp offset inject mode of the port used by pktgen. Supported values: SOF, EOF |
Output Example
- Output from the command
latency -p 0 -r 10 -u 1 -l1000
--------------------+--------------------------------------------------+----------------+ | 1 sec Sampling | Last | | Max | Min | Average | Round trip | --------------------+----------------+----------------+----------------+----------------+ Round trip in nsec | 0 | 0 | 0 | 0 | --------------------+----------------+----------------+----------------+----------------+
The round trip latency Max, Min, Average and Last are presented every second (-u 1
) and reset every 10 seconds (-r 10
).