This is a static archive of our old Q&A Site. Please post any new questions and answers at ask.wireshark.org.

Plotting (/measuring) packet latency (delay) in an 802.11 network.

0

Hi all,

I am trying to plot/measure packet latency (delay) in a 802.11 network using wireshark and I would like to know how people are doing this.

Up unitl now, my settings in the I/O Graph are: Units: Advanced Filter: empty, AVG(*): frame.time_delta_displayed

As I am relatively new to wireshark I am not sure whether this is correct, or not.

Also, as far as I can tell from a previous post, I am NOT supposed to use MAC timestamp filter (wlan.mactime). However, I am not sure if Host timestamp (wlan.hosttime) would be useful. Where do I find more info on this filter? To add to my ignorance, I am not excacly sure whether(/how) I CAN plot wlan.hosttime on the I/O Graph.

I would like to think I have done a thourough google/wireshark search, but I must have missed something. I am relatively new to wireshark, so please forgive my ignorance.

The 802.11 traffic was captured with an AirPcap Tx USB adapter and Wireshark Version 1.6.1 (SVN Rev 38096 from /trunk-1.6) running on a Windoze XP SP3 PC.

Any ideas, or links to sites, books, etc.. would be more than welcome.

Thanks

Alex

asked 25 Jan '12, 11:08

almost_linear's gravatar image

almost_linear
31459
accept rate: 0%

Let's start with a basic question: What are you actually trying to measure ? delay/latency between what and what ?

(25 Jan '12, 11:17) Bill Meier ♦♦

Hi Bill,

I can see how my question is not clear, probably becasue I have gaps in my knowledge.

What I would like to find out is how long it takes a data packet transmitted from a station, to be received and acknowldeged from an access point.

Hope this is more clear.

Thanks Alex

(25 Jan '12, 11:43) almost_linear

One Answer:

0

Bill, I know this is not a very timely answer, but here it goes: You can measure latency in a network, or the delay from client to a server using ping.

From your Windows machine click on Start. Then type in cmd to launch the black "DOS command" window. At the > type in something like >ping amazon.com
Your computer will launch ping and then you will get a reply something like this:

Reply from 72.21.221.176: bytes=32 time< 15ms TTL=128 Reply from 72.21.221.176: bytes=32 time< 10ms TTL=128 Reply from 72.21.221.176: bytes=32 time< 10ms TTL=128 Reply from 72.21.221.176: bytes=32 time< 10ms TTL=128

Ping statistics for 72.21.221.176: Packets: Sent = 4, Received =4, Lost = 0 (0% loss), Approximate round trip in milli-seconds: Minimum = 10ms, Maximum = 15ms, Average = 11ms

This may not always work. One reason may be that the DNS server is not translating URLs to IP addresses properly. The other reason is that firewalls or other filtering is preventing ping from working.

This should get you started. Konrad

answered 16 Apr '12, 16:16

Konrad's gravatar image

Konrad
11
accept rate: 0%

edited 16 Apr '12, 16:17