Simon,
While I can't speak definitively about the Cisco solution, I can tell you about
Emory's Aruba installation. The Aruba and Cisco architectures are similar (but
with some significant differences).
We now have over 1400 APs and 21 controllers - all Aruba. I'm a big proponent
of the centralized architecture of Aruba or Cisco (or others in the
marketspace) for any wireless installation of over a handful of APs because of
the benefits it provides over thick APs. These benefits fall roughly into 3
categories: management, security, and user experience.
Here are just some examples in each category -
Management: I can see and manage the entire system on one console. I can tell
if an AP is up or down, how many users are on it, etc. An also upgrade
firmware for all APs and controllers in under 2 hours, with limited
interruptions to users during the upgrade. Deploying APs is as simple as
setting location code and connecting it to the network - the AP gets its
address via DHCP, looks up its controller via DNS, and connects to its
controller to get its configuration. I can add or delete SSIDs or change
configuration on as many or few of the APs as needs dictate in less than a
minute. New SSID on all APs? - done - no problem! One wireless infrastructure
can support many different wireless networks (guest, voice, etc).
Security: Since all wireless traffic is tunneled back to the controller
(Aruba/Cisco - Trapeze is different), I can apply ACLs or firewall rules for
wireless at the controller. With Aruba, I can apply different firewall rule
sets based on authentication (device, user, etc). I can build a very secure
wireless infrastructure that is easily adaptable to whatever security needs we
need on our various wireless networks. The wireless network is now more secure
than the wired network because of the role-based access control that can be
applied to users.
User Experience: Two words - Ubiquitous roaming. Users can roam across campus
and not lose connectivity (assuming wireless coverage exists). The controllers
take care of the mobile IP stuff without the need to load a mobile IP client on
the users' computer. With Aruba, I can even load-balance users across subnets
(we use class C subnets -24 of them - for all of our wireless users). A user
gets an IP address and keeps it for as long as they are active - no matter
where they roam across campus. I can easily scale the system, too - adding
subnets as needed quickly at the controller, as opposed to adding subnets in
the buildings where the APs are. We needed to do this during our Move-in
weekend last year when our wireless usage grew to over double what we saw the
previous spring.
Without the centralized architecture, there is no way Emory's wireless network
could have grown to its current size and still be manageable. There is A LOT
of value in the centralized architecture.
>>-> Stan Brooks - CWNA/CWSP
Emory University
Network Communications Division
404.727.0226
[EMAIL PROTECTED]
AIM: WLANstan Yahoo!: WLANstan MSN: [EMAIL PROTECTED]
-----Original Message-----
From: Simon Kissler [mailto:[EMAIL PROTECTED]
Sent: Wednesday, February 28, 2007 2:08 PM
To: [email protected]
Subject: [WIRELESS-LAN] LWAPP [was: [WIRELESS-LAN] Upgrade 1200 to lwapp]
Okay, so I've been trying to figure this out and figured I may as well ask.
Where is the cost benefit of the using the controllers and LWAPPs.
The controllers aren't cheap and the APs don't get cheaper even though
they are "light" ? I assume there are some management benefits in this
kind of solution, but have you found them to be worth the money ? Are there
other benefits that aren't as obvious to me that are ?
I like the idea of making management easier and just like any technologist like
shiny new toys, but in the context of overall funding priorities with aging
network equipment in places and other challenges find it hard to justify since
our APs mostly just work and require little touching beyond initial config and
occasional firmware upgrades.
What about this am I missing ?
-Simon
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