Challenging problem: Intermittent issues with secure site(s)

Hi everyone,

I'm hoping that someone here can provide me with some insight into a
rather annoying problem I've been having. I have a private practice
with 4 wired desktops and 4 wireless laptops. All 8 computers utilize
two online services called AdvancedMD and DigiChart. The wired
computers work just fine, the wireless computers on the other are
plagued with connectivity issues. These issues cost the doctors and
their nurses a lot of lost time and frustration. I've tried
everything I can think of (and performed many experiments), but all to
no effect. I've talked at length to the two service providers, but
they haven't been able to give me any advice. I tend to think that
the majority of their clients use wired networks and so they don't
have a lot of experience with this wireless problem I'm having.
I'll jump into the details:

The problem
==========
·In the course of a typical day the laptops loose their connection to
the online services 1 or more times (usually a lot more)
·Once in a blue moon the laptops won't loose connectivity at all
throughout day

Symptoms and observations
======================
·The error message is "The page cannot be displayed" or a similar
browser error
·The problem does not effect normal network functionality (such as
web browsing, email, or shared drives)
·F5 works sometimes, other times not
·The problem occurs on each laptop independently and at different
times
·There is no discernable periodicity to the errors to provide some
kind of a hint
·No obvious network errors are present except for the occasional
packet timeouts that I've always associated with wireless networks
·The wired computers do not have any problems

Other technical stuff that might be useful
===============================
·Current wireless access point: Buffalo Technology WHR-HP-G54
·3 laptops of one make and model, 1 of another make and model (all 4
do the same thing)
·I have tried several other access points
·I have not tried an expensive access point like Cisco's Aironet.
·The web services use SSL to secure their websites
·Both services rely heavily on ActiveX so only Internet Explorer will
work
·The practice is in a hospital so there's plenty of interference
from medical equipment

I really need a fresh perspective. I've been dealing with this
problem for so long my mind has grown stale. Thanks in advance for any
advice you can give me.

Matthew

 

Hi Matthew

The Buffalo APs are among the best Entry Level WIFI devices.

My suspicion would be that the heavy encryption + the noisy environment
throw the Wireless out of Sync.

I would set a Wired computer and a wireless one in a Faraday cage (if you
have one) and see how it works none stop through out the day (or make an
experimental installation off premise).

Trying 802.11a devices might do the trick too, if the issue is excessive
noise.

There is also a remote possibility that there is some incompatibility with
the product. Wireless is not as flexible as wire to move and oOf mainstream
protocols and encryption forms, might bogged down the system after a while.

Providers of Entry level Wireless devices may know nothing about such an
issue.

Cisco on the other hand are providing service to Medical Centers, might be
worth while to call.

Example, http://www.cisco.com/web/strategy/healthcare/hospitals_pocono.html

Jack (MVP-Networking).





Hi everyone,

I'm hoping that someone here can provide me with some insight into a
rather annoying problem I've been having. I have a private practice
with 4 wired desktops and 4 wireless laptops. All 8 computers utilize
two online services called AdvancedMD and DigiChart. The wired
computers work just fine, the wireless computers on the other are
plagued with connectivity issues. These issues cost the doctors and
their nurses a lot of lost time and frustration. I've tried
everything I can think of (and performed many experiments), but all to
no effect. I've talked at length to the two service providers, but
they haven't been able to give me any advice. I tend to think that
the majority of their clients use wired networks and so they don't
have a lot of experience with this wireless problem I'm having.
I'll jump into the details:

The problem
==========
·In the course of a typical day the laptops loose their connection to
the online services 1 or more times (usually a lot more)
·Once in a blue moon the laptops won't loose connectivity at all
throughout day

Symptoms and observations
======================
·The error message is "The page cannot be displayed" or a similar
browser error
·The problem does not effect normal network functionality (such as
web browsing, email, or shared drives)
·F5 works sometimes, other times not
·The problem occurs on each laptop independently and at different
times
·There is no discernable periodicity to the errors to provide some
kind of a hint
·No obvious network errors are present except for the occasional
packet timeouts that I've always associated with wireless networks
·The wired computers do not have any problems

Other technical stuff that might be useful
===============================
·Current wireless access point: Buffalo Technology WHR-HP-G54
·3 laptops of one make and model, 1 of another make and model (all 4
do the same thing)
·I have tried several other access points
·I have not tried an expensive access point like Cisco's Aironet.
·The web services use SSL to secure their websites
·Both services rely heavily on ActiveX so only Internet Explorer will
work
·The practice is in a hospital so there's plenty of interference
from medical equipment

I really need a fresh perspective. I've been dealing with this
problem for so long my mind has grown stale. Thanks in advance for any
advice you can give me.

Matthew

 

Jack,

Thanks for the reply. I found another article similar to the one you
linked to in your post. It described a hospital that was successfully
networked wirelessly using Trapeze Networks equipment. Looks like I
need to stop playing around with the entry level stuff (or get a
Faraday cage and try some more experiments).

Thanks,
Matthew

 

I did some tech support for Buffalo. Their radio's are a piece of
crap(probably why they are so cheap). I use Linksys MIMO technology and I
have no problem. If there is alot of interference in your area, you might
want to try this technology instead of something much more expensive. Most
higher end devices use better radio's then lower end.
Jack,

Thanks for the reply. I found another article similar to the one you
linked to in your post. It described a hospital that was successfully
networked wirelessly using Trapeze Networks equipment. Looks like I
need to stop playing around with the entry level stuff (or get a
Faraday cage and try some more experiments).

Thanks,
Matthew