[Novalug] pauses in wireless connection

[Jon LaBadie]

On Thu, Jun 05, 2008 at 11:24:25AM -0400, Jon LaBadie wrote:
> I'm having an annoying behavior with my FiOS WiFi
> setup.  The equipment in question is:
> 
> 	ActionTec MI424WR broadband router/wifi access point
> 	Dell Vostro 1500 laptop with Intel 3945 wifi card
> 
> The laptop is the only wireless equipment I have.  I often
> use it for browsing the net while TV watching and to remotely
> access other hardwired computers on my SOHO lan.
> 
> Quite often the network connection for an application will
> stop working.  The three apps most often affected ssh, firefox,
> or vncviewer/rdesktop.  Most often this happens after I have
> not used the application for a while, worked in another window
> for a few minutes, got caught up in the action on tv for a bit,
> or other reasons.  When I return to the application, the network
> does not respond.
> 
> Another way the pauses show up is in the middle of working.  I
> might be typing in the ssh or browser window, hesitate a second or
> two, and when I resume typing, nothing, no response, no echo of
> the characters.  This type of unresponsiveness often does reverse.
> But not for 1 or 2 minutes.  Then my buffered characters
> suddenly appear and are acted upon by the remote application.
> 
> In contrast, the first type of behavior never, when I've been away
> from the application for a while, never returns.  Yet it is not
> a loss of network connection.  I can work in other windows or a
> new window even while the dead one remains dead.
> 
> The laptop is dual boot, Ubuntu Hardy Heron and Windows XP Pro.
> I see the same behavior under both OSs.  I don't see these
> behaviors on the hardwired connections to the ActionTec.

It was suggested that TCP KeepAlive might be needed to keep the
connection up during periods of inactivity.  I tried this last
night with the PuTTY ssh client from Windows XP.  Just as with
the Ubuntu ssh client, it previously exhibited hang-ups.

I turned on keepalives in putty at a frequency of every 15 seconds
and connected to my remote computer (a Solaris 9 system on the lan).
After I worked for about 10-15 minutes I started browsing the net
using Ubuntu's firefox and returned to the ssh window about 10 min
later.  As before, it was dead.  The TCP keepalives did not help.

Now the weird observation.  For connection to my network when I'm
traveling I allow ssh connections through the router to that Solaris
computer.  On a whim, I used the same putty client on Ubuntu,
which was connected via WiFi to the ActionTec router, but I pointed
it at the external IP address provided by Verizon for my network.
This established the same connection to my Solaris box, but by
sticking an internet loop into the route between the two systems.
This connection did not hang for the entire evening.  Yet I made
another second "direct" connection between the two systems, and
that did hang even while the "indirect" connection stayed up.

???

jl
-- 
Jon H. LaBadie                  jon at jgcomp.com
 JG Computing
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 Reston, VA  20194		(703) 787-0922 (fax)