Wireless Network speed question...

Recently in my company we have replaced the antenna on the roof as well
as the coaxial cable that is connected to it. We have two other
locations that we are feeding Internet to from our location. The
connection speed fluctuates, I send pings to both locations and
sometimes I get replies ranging from 400ms to 12ms. The coaxial cable
connects to a breeze net that we have in the office, that is the only
peice of hardware that we havent replaced other than the other antennas
in the other buildings. We are trying to figure out what it could be
that is causing these speeds to fluctuate. Any feedback would be
greatly appreciated.


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northface202 wrote:
> Recently in my company we have replaced the antenna on the roof as well
> as the coaxial cable that is connected to it. We have two other
> locations that we are feeding Internet to from our location. The
> connection speed fluctuates, I send pings to both locations and
> sometimes I get replies ranging from 400ms to 12ms. The coaxial cable
> connects to a breeze net that we have in the office, that is the only
> peice of hardware that we havent replaced other than the other antennas
> in the other buildings. We are trying to figure out what it could be
> that is causing these speeds to fluctuate.

A zillion things: weather conditions, trees or leaves getting in the
way, wobbly connectors somewhere or other, wobbly bearings on the
antennae, interference from the guy in hut 23 with a cyclotron, from the
lady with the walkabout 2.4Ghz phone, from your microwave oven etc etc.

Jeff will be along shortly, and will ask for make, model and version
numbers of everything, plus heights, distances, types of cabling,
quantity and types of trees, houses, airports, etc between you and your
target....

On Thu, 6 Dec 2007 15:24:15 -0500, northface202
<(E-Mail Removed)> wrote:

>Recently in my company we have replaced the antenna on the roof as well
>as the coaxial cable that is connected to it.

Let me guess. An omnidirectional antenna, with LOTS of gain, fed with
lots of LMR-400, and marginal waterproofing? I'll see if I can find
the email I sent to someone with a similar omni install. My
appologies if you did it right and use sector antennas.

>We have two other
>locations that we are feeding Internet to from our location.

On the same frequency and channel? If so, welcome to mutual or
self-interference.

>The
>connection speed fluctuates, I send pings to both locations and
>sometimes I get replies ranging from 400ms to 12ms.

Only 12msec? No timeout errors? Most of my pings for local systems
are 2msec or less. For long range, I have a 5 mile link that does
about 5msec minimum. Are you perhaps going through a repeater (range
extender) somewhere? If you're trying to measure latency on a live
system, with users doing their downloading, your latency is going to
look roughly like what you describe. Some firewalls are smart enough
to prioritize packets and usually put ICMP pings last. If you're
running QoS, that's what you'll see.

>The coaxial cable
>connects to a breeze net that we have in the office, that is the only
>peice of hardware that we havent replaced other than the other antennas
>in the other buildings.

What model Alvarion BreezeNet? What coax cable? How long a coax
cable? How far a path? Done any site surveys? Spectrum analyzer?
How much traffic? Are you monitoring traffic? You know, like NUMBERS
please.

>We are trying to figure out what it could be
>that is causing these speeds to fluctuate.

Ummm... perhaps it's users on the wireless? Could be interference. If
you get the same variations with no users on the system, then it's
likely. However, you should see timeout errors and much larger
variations in latency with interference.

>Any feedback would be
>greatly appreciated.

Sorry. Feedback hurts my ears. Turn down the microphone gain.

Incidentally, if you're running a WISP, you might find this mailing
list useful:
<http://isp-wireless.com>

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# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 (E-Mail Removed)
# http://802.11junk.com (E-Mail Removed)
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