Wired vs wireless - comm trace needed

All,

2 fairly new Zebra label printers, both can attach to the System i either
wired or wireless. When attached wireless, labels print in fits and starts.
For example, a 75-label run typically prints 20-25 labels, pauses 7-10
seconds, prints 1-5 labels, pauses 7-10 seconds, prints 1-5 labels, pauses
7-10 seconds, prints 1-5 labels, pauses 7-10 seconds, etc, etc, etc until
finished. The exact same spool file prints at rated speed from start to
finish if wired attach.

The same device description is used on the System i. The only change I make
for wired/wireless is vary off, change IP address, vary on.

Zebra suggests a sniffer to see what's going on comm-wise. Sound reasonable
but that's all new to me. I know comm traces can be done on the System i
because Supportline has had me do it in the past. They've always been
emailed to IBM for interpretation, however.

Suggestions? Should I use System i comm trace tools? Or get some Windows
freeware sniffer? If Windows, what do you recommend? Will windows sniffers
interpret anything for me? The traces I emailed IBM looked like Greek to
me.

If this morphs into a thread on Windows sniffers, I'll move the thread to
PCTECH.

Thanks.