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Contact me at david@geercom.com, via this form or at 440-964-9832 (Fax:440-964-2172). The ACUTA Journal of Communications Technology 802.11 Topologies Excel in Higher EdBy David Geer Accommodating Students at RIT Rochester Institute of Technology (RIT) prepared for the possibility of an upgrade in 802.11 protocols and APs while deploying 802.11b. By installing two Ethernet jacks at every AP location during the 802.11b installation, RIT made ready to carry two standards to ease migration. Should 802.11a or g look inviting, RIT can test the additional protocol and APs while maintaining 802.11b coverage. For RIT, Wi-Fi is an extension of a flat, single network on a single subnet. "We expect that as wireless usage grows, we are going to run into the typical problems that are present on a flat, single network. That will dictate the need to change the topology," says Patrick Saeva, program manager for the IT department at RIT (pjsits@rit.edu). For now, this simple flat topology guarantees seamless roaming for campus constituents. RIT plans eventually to consider additional wireless services beyond surfing and basic Internet use. As traditional return on investment concerns (and financing) are not obstacles, only a strong demand for expanded services will determine implementation. Calculating ROI is a difficult process. RIT's decision to invest in wireless services was based on whether it would help the students. A similar philosophy guides the decision-making process at other educational institutions. Flexibility at Syracuse University "We bought APs that will accommodate either 802.11a or g," says Lee Badman, network engineer at Syracuse University (lhbadman@syr.edu). With a solid 802.11b base, Syracuse would lean toward advancing to 802.11g when the need for greater speed arises. The 802.11g standard provides the same speeds as 802.11a but within the 2.4 GHz ISM band. (Residing in the 2.4 band is the commonality between 802.11g and b that makes g backward compatible with b.) The wireless topology is a neutral, demilitarized-zone network that sits outside the university's main network. It exists on one subnet across the campus. A gateway/firewall provides protected access. "It's considered untrusted, and the gateway/firewall separates the users from the rest of the campus," says Badman. Syracuse's wireless LAN has presented no problems in the areas o f speed, performance, and reliability. Security risks are mitigated by the value of having wireless LAN service and by the separation from other campus networks. Badman expects that there will always be some security risks. Dual-Mode Solution at UNC The University of Northern Colorado uses Vernier Networks' IS 6000 (an integrated control server and access manager) to authenticate students on its 802.11a and b networks. The wireless network is separated from the campus's wired network. Following a site survey (performed by NetCom International) Vernier was selected along with Cisco for the APs and the wireless virtual private network (VPN). Asked why UNC uses both 802.11a and b, Jeanette Van Galder, director of administrative information technology (jeanetter.vangalderl@unco.edu), said, "While the 802.11b network interface cards [NICs] are more prevalent in the consumer market, we wanted a dual-mode solution for individuals requiring higher speeds and additional capacity." Segmentation from the primary network is accomplished with VLANs. UNC uses Cisco's VPN for faculty and staff for data encryption and for drive mappings to the current active directory, says Van Galder. UNC installed in-house based on NetCom's findings for the optimal placement of APs. It also installed its own wireless security using not only VPN but also LDAP. Van Galder says that although they use the network only for WLAN, VoIP could be considered among added services. Productivity and efficiency improvements are a big part of UNC's ROI. Because students are sharing files directly between laptops, server loads are decreasing. Students are spending more time on the network and are more productive. |
