nanog mailing list archives

Re: Verizon EVDO Issues


From: Seth Mattinen <sethm () rollernet us>
Date: Wed, 08 Apr 2009 11:41:03 -0700

Alexander Harrowell wrote:
On Tuesday 07 April 2009 22:10:24 Charles Wyble wrote:
Been troubleshooting a very strange problem for a couple of weeks now.

I have a few hundred systems deployed throughout the United States
utilizing EVDO connectivity with Verizon as a carrier. They are stationary.

Over the past few weeks clusters of them in SF and Lewisville TX and a
few other areas have been failing intermittently. They are offline for
several days, then online for a few days then go offline again. They are
running Linux and PPPD.


Do they maintain a continuous data link in normal operation (like, say, 
connectivity for a LAN, or backhaul for a camera or some such), or do they 
request the data link when they need to send [whatever] (like a discrete SCADA 
system)? My (user only) experience is that cellular data service doesn't 
handle long sessions well. 


I have a few Sprint EVDO cards. They go into standby when nothing is
actively going on and fire up within seconds when there is something to
do. I regularly use everything from SSH to streaming video without any
issues. I only notice the delay with SSH when I don't type anything for
a few minutes and it has to come active again, but I can leave it idle
for hours and it never drops.

As far as the OP goes, let them replace the cards if they think that's
the problem. You and I may suspect something else is up, but if that's
on their checklist, it is what it is.

~Seth


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