Wireless Bandwidth

Just trying to confirm whether or not wireless has moved on enough for
me to consider installing it at work.

Basically I need to ensure that each desktop/laptop gets a 100Mbit
connection i.e. as you would get from a switch and wired cards.

It is my understanding that Access points act as hubs, have they moved
on from this yet or is there another wireless option that I should be
considering.

Thanks for your help

Les


Les

Les wrote:
> Just trying to confirm whether or not wireless has moved on enough for
> me to consider installing it at work.
>
> Basically I need to ensure that each desktop/laptop gets a 100Mbit
> connection i.e. as you would get from a switch and wired cards.
>
> It is my understanding that Access points act as hubs, have they moved
> on from this yet or is there another wireless option that I should be
> considering.
>
> Thanks for your help
>
> Les

If you really need 100 Mb/s per PC then the current generation of
wireless won't cut it. Try again in a couple of years.

But I'll bet that you don't really need 100 Mb/s. You may want to
buy some 802.11g equipment -- enough for a WAP and a handful of PCs --
and see if the users notice the bandwidth difference enough to
register realistic, specific, complaints.
--
Cheers, Bob

Les <(E-Mail Removed)> wrote:
> Just trying to confirm whether or not wireless has moved on enough for
> me to consider installing it at work.
>
> Basically I need to ensure that each desktop/laptop gets a 100Mbit
> connection i.e. as you would get from a switch and wired cards.
>
> It is my understanding that Access points act as hubs, have they moved
> on from this yet or is there another wireless option that I should be
> considering.
>
> Thanks for your help

I've always considered wireless to be more of a home networking phenomenon
rather than an office one. WiFi came along at just the right time to allow
home users to avoid having to route hundreds of feet worth of Ethernet
cabling through their houses. In an office environment, this is not a
problem as wires are routinely routed through the ceilings or floors as
necessary to get to the desks. And the speed of wires is still several times
faster than wireless, due to full- vs. half-duplex, switching, access-point
distance efficiencies, etc. And you can't beat the security of wired
switching interfaces -- you simply can't monitor the network traffic without
cutting into everyone's wires.

That being said, maintaining a wireless access point mainly for the laptops
of personnel who go on the road regularly and come into the office
irregularly might be quite beneficial for one's office. It saves on having
to maintain a technologically sophisticated desk space for these people with
fully wired access points nearby. You can pretty much shove them and their
laptops into the cafeteria if you want. Certain proprietary versions of the
Wireless-G protocol can run at upto 108Mbits/s. Mind you this is 108Mbps at
half-duplex, and dependent on distance from the access points, etc.

Yousuf Khan

In article <NR9Ic.151986$(E-Mail Removed) e.rogers.com>,
Yousuf Khan <(E-Mail Removed)> wrote:
(snip)
>cabling through their houses. In an office environment, this is not a
>problem as wires are routinely routed through the ceilings or floors as
>necessary to get to the desks. And the speed of wires is still several times

We find wireless useful at work because most of our employees have
wireless-capable laptop computers that they can use away from their
desks - in conference rooms that we share with other companies in the
building, etc.

>faster than wireless, due to full- vs. half-duplex, switching, access-point
>distance efficiencies, etc. And you can't beat the security of wired
>switching interfaces -- you simply can't monitor the network traffic without
>cutting into everyone's wires.
(snip)

Yes - I figure it's just best to assume that it's insecure, and we're
looking at using VPN stuff, etc. to give the actual network security
rather than WEP, WPA and whatever. Then, the same cryptography also
protects against people who instead get into our wired network (via
the communal patch room or whatever).

-- Mark

Currently we provide 1 Gbp/s to each desktop so cutting down to
100Mbp/s is quite a big drop. Is the 100Mbp/s provided by the access
point provided to each laptop or is it shared i.e. 10 users on the AP
means connecion speeds of 10 Mbp/s?

Cheers for the help btw

Les wrote:
> Currently we provide 1 Gbp/s to each desktop so cutting down to
> 100Mbp/s is quite a big drop. Is the 100Mbp/s provided by the access
> point provided to each laptop or is it shared i.e. 10 users on the AP
> means connecion speeds of 10 Mbp/s?

It's shared.

Yousuf Khan

"Yousuf Khan" <(E-Mail Removed)> wrote in message news:<p5BIc.106$(E-Mail Removed) ogers.com>...
> Les wrote:
> > Currently we provide 1 Gbp/s to each desktop so cutting down to
> > 100Mbp/s is quite a big drop. Is the 100Mbp/s provided by the access
> > point provided to each laptop or is it shared i.e. 10 users on the AP
> > means connecion speeds of 10 Mbp/s?
>
> It's shared.
>
> Yousuf Khan

It's not. We are using Catalyst 4600 switches with gigabit cards.

Les Ryall

Les wrote:

> "Yousuf Khan" <(E-Mail Removed)> wrote in message news:<p5BIc.106$(E-Mail Removed) ogers.com>...
>
>>Les wrote:
>>
>>>Currently we provide 1 Gbp/s to each desktop so cutting down to
>>>100Mbp/s is quite a big drop. Is the 100Mbp/s provided by the access
>>>point provided to each laptop or is it shared i.e. 10 users on the AP
>>>means connecion speeds of 10 Mbp/s?
>>
>>It's shared.
>>
>> Yousuf Khan
>
>
> It's not. We are using Catalyst 4600 switches with gigabit cards.
>
> Les Ryall

Bandwidth is a shared resource with switches, but it is not the
per-port bandwidth that is shared, it is the backplane bandwidth.
With a Cisco Catalyst 4503 stocked with GbE line cards, the peak
bandwidth of each GbE port is (no surprise) 1000 Mb/s. The shared
backplane bandwidth of that 4503 is 28Gb/s, so configurations with
a handful of GbE ports will not be limited by the backplane, but
a maxed-out 4503 with 96 GbE ports could be bottlenecked by the
backplane. {Yeah, there are other performance constraints with
switches -- I'm being simplistic to make a point.}

For a WiFi link segment, the peak bandwidth is 11 Mb/s for 802.11b
and 54 Mb/s for 802.11g. For a single WiFi link with N devices
(e.g., laptops) managed by one WAP, the link's bandwidth is, indeed,
shared by the laptops. If a 802.11b link were shared equally by
11 laptops, then 1 Mb/s per laptop is an upper bound. The good news
is that laptops rarely present an equal request load, so bandwidth
sharing is not equal. The bad news is that the 1 Mb/s per laptop
of my example ignores protocol overhead which, on WiFi, can be a
huge tax.
--
Cheers, Bob

Les wrote:
> "Yousuf Khan" <(E-Mail Removed)> wrote in message
> news:<p5BIc.106$(E-Mail Removed) ogers.com>...
>> Les wrote:
>>> Currently we provide 1 Gbp/s to each desktop so cutting down to
>>> 100Mbp/s is quite a big drop. Is the 100Mbp/s provided by the access
>>> point provided to each laptop or is it shared i.e. 10 users on the
>>> AP means connecion speeds of 10 Mbp/s?
>>
>> It's shared.
>>
>> Yousuf Khan
>
> It's not. We are using Catalyst 4600 switches with gigabit cards.

He's talking about the WiFi bandwidth.

Yousuf Khan