Hoping you can give me some guidance.

I'm evaluating PP to see if I can troubleshoot wireless cellular issues I'm having (poor latency in certain day-time patterns). I would like to log hop times every 5 minutes for the last hop (cellular gateway) but I'm getting 'wake up' delays. The problems I'm trying to characterize with PP are related to post 'wake up' communications but I fear I am only logging the first exchange.

Here is an example.

PPS shows:

5 5594 ms [a.b.c.d]
6 10 ms [e.f.g.h]
7 17 ms [i.j.k.l]
8 30 ms [e.m.n.o]
9 18 ms [e.m.p.q]
10 23 ms [r.s.t.u]
11 18 ms [v.w.x.y]
12 73 ms [v.w.z.aa]
13 66 ms [v.bb.cc.dd]
14 71 ms [ee.ff.gg.hh]
15 78 ms [ee.ff.gg.hh]
16 69 ms [ii.jj.kk.ll]
17 70 ms [ii.jj.mm.nn]
18 72 ms [ee.oo.pp.qq]
19 5500 ms [111.222.333.444]

Note the last hop is over 5 seconds.

If I ping the same device:

Pinging 111.222.333.444 with 32 bytes of data:

Reply from 111.222.333.444: bytes=32 time=3071ms TTL=41
Reply from 111.222.333.444: bytes=32 time=238ms TTL=41
Reply from 111.222.333.444: bytes=32 time=236ms TTL=41
Reply from 111.222.333.444: bytes=32 time=236ms TTL=41

Ping statistics for 111.222.333.444:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 236ms, Maximum = 3071ms, Average = 945ms

Note the first ping time.

It is the performance of the later communications I would like to log in PP.

If I could execute a leading ping or eq. before each logged sample, it might help. Is that possible?

Any ideas would be appreciated.

JoeG

Hi, Joe.

There are a couple of possibilities here.

First, you could just set your trace interval low enough so your cellular gateway never goes to sleep. That's the easiest solution for this. You can play around a bit with trace intervals until you get one that keeps the cellular link awake all the time (maybe 15 seconds instead of 5 minutes).

A second option, if you're using PingPlotter Pro, is to use a script we built a couple years ago for someone that sends out a single (unlogged) ping to the final destination, then waits a bit (1 second in the current version, but it could be upped a bit to match what you need), and then it sends out the full trace request, giving the cellular link time to wake up. This script may have some issues, but a quick review makes me think it should do what you want.

If you're interested in getting this script, shoot us an email at support@pingplotter.com and reference this thread and we'll be happy to send a copy over to you (with the appropriate warnings, of course).

- Pete

Thanks for the quick response.

For some reason, when I use intervals of less than 3 minutes, the failure mode goes away. I suspect it's the access point authorization, re-provisioning or something like that.

It's worth it to me to try the script even if it's a work in progress. (e-mail to follow)

Cheers,
JoeG

A quick test of the script looks very promising!

I put an eight second delay in to start and I'll be running over the w/e.

I'll update the thread with my results.

Cheers,
JoeG

Script works great!

I'm getting good data now with the 5 minute interval and an 8 second preceding ping.

Thanks again for your assistance.