As more enterprises deploy wall-to-wall Wi-Fi, they're finding end users voting with their network interface cards: given a choice, they go with wireless rather than wired access.
In pervasive wireless LANs (WLAN), depending on the industry segment, ever-more IT departments are finding 50% to as much as 90% of edge switch ports sitting idle.
One well-known Northeast college is starting to evaluate 802.11n as an upgrade to its campus-wide 802.11abg WLAN, based on Aruba Networks gear. Parts of the network are saturated with lots of users and heavy traffic because, despite plenty of Ethernet ports, students use wireless almost exclusively. “We think 11n will reduce but not totally eliminate wired ports,” says the campus networking director, who requested anonymity.
Colleges and universities have been among the first to discover and tackle what is, for IT, an entirely novel development and an issue that touches a nerve whenever we raise it.
“We haven't been rushing around looking to pull out wired switches,” says Dan McCarriar, director of network and production services, Carnegie Mellon University, in Pittsburgh. CMU has recently deployed a campus-wide 802.11n WLAN based on Aruba and Xirrus gear. “But as the existing wired infrastructure reaches 'end of life' and we look towards replacement, we're definitely going to be evaluating a scaled-back deployment of wired.”
As noted in a previous story, the California State University system of 23 institutions did a port-by-port analysis of Ethernet use in preparing a rollout of Aruba 802.11abg (upgradeable to 802.11n) WLANs on all campuses. Not a single campus had greater than 50% wired port use, and most had far less than that, says Michel Davidoff, CalState's director of cyberinfrastructure services.
He called the results “mind-boggling.” A careful analysis concluded that by reducing Ethernet ports to reflect actual usage, CalState could eliminate 2,500 switches, and save about $30 million over five years in capital costs, hardware staging and installation. And that didn't include electricity and heating/cooling savings.
No one, repeat no one, is saying scrap the Ethernet cabling and edge switching infrastructure tomorrow. But plenty of IT professionals are starting to ask exactly what the real bandwidth requirements of their users and applications are, and how these change in peaks and troughs during a day or week.
For industries, companies and locations where mobility is a primary enabler of productivity, the answers to these questions can be used to make realistic assessments of when and where to rely on the WLAN – a well-designed, well-managed, secure WLAN – and cut the cord for most if not all clients.
