Two wireless LANs better than one, Carnegie Mellon says

802.11n wireless net decision explained by university

CMU anticipates four major integration issues with its dual-WLAN approach.

Issue 1: integrating network architectures

One reflects the different architectures of the two vendors, Aruba with its centralized approach, Xirrus with a more distributed model. "We'll need to come up with a reasonable compromise between the two models," McCarriar says. For now, CMU plans to monitor traffic patterns on the two networks, and see how the gradual growth of 802.11n clients impacts the different architectures.

Issue 2: integrating authentication models

Each vendor has its own "captive" Web portal to capture a wireless user logging on, and its own authentication methods, though both are based on the 802.1X standard, which CMU is adopting for Wireless Andrew 2.0. CMU has had its own authentication portal for years. How can these be rationalized into a consistent experience for users? The geographic separation of the networks will be an advantage, because it will minimize the chance of clients physically roaming from one WLAN to the other.

CMU is exploring two options. One is co-development work with Xirrus, creating code that would let users share authentication keys between the two networks. The second option exploits Aruba's push to apply the more granular and strong wireless security controls to wired clients. McCarriar thinks it might be possible to bring all clients through the Aruba portal, which would act in effect as a front-end to Xirrus' authentication.

Issue 3: roaming

But roaming itself will be an issue, as users moving from dorms to classrooms for example, McCarrier acknowledges. How will user information, including authentication, be shifted from one Aruba to Xirrus and back again, without forcing a complete break and re-association and re-authentication? Right now, that's an unknown.

Issue 4: integrating management

As with authentication, CMU has its own home-grown network management and monitoring systems. And of course, so do the two WLAN vendors. "The big thing I'm worried about is aggregating statistics between the two platforms," McCarriar says. "That will mean some [code] development." The current idea will be to explore how to pull relevant monitoring and management data from the two brands of equipment into CMU's existing system.

Radio frequency site surveys will occupy the IT team and vendors until early 2008. Deployment is expected to start shortly after, as fast as both companies can deliver 802.11n products, and be completed by the end of 2008.

Join the PC World newsletter!

Error: Please check your email address.

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

John Cox

Network World
Show Comments

Most Popular Reviews

Latest News Articles


PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?