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March 15, 2002
Networking Trends: Consolidating Your School Network
By Todd McIntire
Two emerging technologies, Virtual Private Networks and IP Telephony, can help schools make the most of their existing network infrastructure.
Each year, new systems are introduced to perform specialized networking tasks that were previously done on a single server. For example, school networks that once had a single server performing file storage, print service, and e-mail management have moved to separate, dedicated boxes for each application. This movement toward specialization is driven by the need to simplify each element in the network. By reducing the number of tasks performed by each component of the network, we increase efficiency and thereby improve system-wide performance.
At the same time, however, specialized components increase the overall cost of networks by requiring additional hardware and adding to the burden of integrating the individual systems into a functional whole. Perhaps not surprisingly, then, in key areas of networking there has been a shift toward consolidation-using existing systems to perform a number of tasks rather than implementing separate, dedicated systems. This trend is particularly appealing to school technology professionals who are looking for ways to get more performance from the networks they already have.
Here, we examine Virtual Private Networks and IP Telephony, two emerging technologies that maximize the value of existing systems by consolidating previously separate functions onto one network.
Virtual Private Networks
A Virtual Private Network is a private tunnel through the public Internet that allows remote computers or local networks to communicate safely without a dedicated circuit. A VPN can be used to provide students and teachers with remote access to a school network or to connect two or more local networks together into a wide-area network.
A VPN is established by software or hardware that resides at the gateway between the private and public network. A VPN device-either a software-based VPN client or a hardware-based VPN service-is required at the gateway at each end of the connection. At the sending end, the gateway device encrypts data before it travels through the public Internet. At the receiving end, the gateway device decrypts the data and allows it to pass into the private network. A VPN device can also serve as a firewall to protect a local network from unauthorized access.
The primary advantage for schools using a VPN for remote access and wide-area connectivity is that it reduces costly dedicated telecommunications circuits. In the case of remote access, for example, using VPN technology eliminates the need for modem banks and dedicated dial-in phone lines. Instead, users connect to their local ISP and then launch a VPN client application that establishes a secure connection over the Internet to their school network. Because VPNs send data over the public Internet, however, there is no guarantee that the amount of bandwidth available at any given time will be enough to handle data such as voice or video.
Following are VPN products available from major networking companies.
Avaya, a recent spin-off from Lucent Technologies, offers the VSU series of VPN gateways for remote access and the VPN Firewall family for wide-area connectivity. (866) GO-AVAYA
Check Point's VPN-1 Gateway and VPN-1 Client are part of a comprehensive set of products for remote access and wide-area connectivity. VPN-1 products are available for Windows, Linux, and Unix servers and dedicated VPN devices. (650) 628-2000
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| The Cisco VPN 3000 series can support up to 10,000 users. |
Cisco offers both VPN clients and hardware-based VPN devices. The VPN 3000 Series Concentrator line includes models that support small organizations (fewer than 100 remote users) up to large organizations (more than 10,000 remote users). The Cisco VPN client, included with any hardware purchase, is available in versions for Windows, Macintosh, and certain wireless devices. (800) 553-NETS
Microsoft has integrated VPN technology into both its desktop and server operating systems (VPN client software is included in Windows NT, 2000, and XP). Microsoft's Internet Security and Acceleration server can be configured as a VPN server to support secure, gateway-to-gateway or client-to-gateway communication. (800) 426-9400
If your school has a Novell network, you can add BorderManager VPN Services as the virtual network component of the BorderManager Enterprise Edition 3.6 suite. This suite provides secure remote authentication services and firewall services. VPN clients are available for Windows 9x, 2000, and NT. (888) 321-4272
IP Telephony
Traditionally, when you make a call on a telephone, your voice is carried over dedicated analog circuits. But with IP Telephony, also known as Voice over IP (VoIP), voice information is transferred over a network.
VoIP networks require special IP (Internet Protocol) telephones that break voice data into packets for transport along the network. IP phones are really specialized personal computers: they have a processor, an Ethernet port, and an IP address for Internet access. Many IP phones also include small screens for Web browsing and reading e-mail.
The major advantage of VoIP for schools is the potential to reduce costs. VoIP can eliminate the need for dedicated voice systems such as PBX and Centrex. In addition, because the data network carries both data and voice communications, schools can save on wiring and equipment. And because the voice packets transfer over a private data network or the Internet, there are no call or long distance charges. Of course, in order for all fees to be avoided, the individuals at both ends of the call must have VoIP telephones and adequate network and Internet connections.
The disadvantage of VoIP is that traditional data networks are not designed to move data with the even, steady flow required of voice communications. Therefore, the greatest challenge of VoIP is getting Quality of Service (QoS) from the data networks that carry the voice packets. (QoS means that the network can support the real-time flow of data required by voice communications.)
Here is a breakdown of several major vendors in the IP telephony market.
 | | 2Com's NBX25 communication system has single-wire cabling for voice and data. |
3Com's NBX network telephony systems can support small (up to 25 phones) to large (up to 750 phones) organizations. Recent enhancements to the NBX platform include the ability for users to be notified via e-mail of new voice mail messages. (800) NET-3COM
Avaya offers IP Office as a VoIP solution for small to medium organizations (up to 100 phones). Avaya's 4630 IP Screenphone, which includes a 320 x 240 pixel touch screen that displays HTML and runs Java applets, has the potential to replace the PC in some situations. (866) GO-AVAYA
Cisco has collected its telephony products in a line called AVVID (Architecture for Voice, Video, and Integrated Data). AVVID products include Catalyst data switches that provide guaranteed QoS, the 7960 IP telephone, and Call Manager software. (800) 553-NETS
Mitel Networks produces the 3100 ICP for small organizations (up to 24 phones) and the 3300 ICP for larger organizations (up to 700 phones). Mitel's dual-port 5010 and 5020 IP phones are particularly convenient, since one port can be used to link to a PC. This means only one Ethernet drop is required to support both an IP phone and a PC. (800) 648-3579
Nortel is an old name in enterprise telephone systems and continues to develop innovative IP telephony products. The company's Business Communications Manager (BCM 2.5) is appropriate for organizations requiring up to 100 phones. (800) 466-7835
SpectraLink provides NetLink IP wireless telephones that can be integrated with Cisco's CallManager application and wireless LAN access points. (800) 398-0864
Vodavi offers a full line of VoIP options, including the Infinite DVX, Starplus, and Triad systems. The recently released XTS phone can be upgraded over the network as new phone features become available. (800) 843-4863
Todd McIntire is vice president of the LearnNow division of Edison Schools.
 Specialize or Consolidate?
When do you buy components and when do you go with a rack system? In some cases, it's better to divide functions among separate boxes; in other cases it is an advantage to consolidate multiple functions on a single box. Ask yourself the following questions to help you decide:
- What is the difference in cost between the separate components and the consolidated system, taking into consideration both the initial cost and the additional resources required to maintain each system?
- What will be the difference in the time required to integrate the systems into the network?
- How many points of failure are in the competing systems? What are consequences of each type of failure?
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Additional Networking Trends
Here are some other networking developments to watch in the near future.
- Load Balancing. Load balancers are data switches that are sensitive to the type of data being transmitted and can balance the flow of data accordingly. Load balancers give priority to voice and video streams to ensure Quality of Service.
- Metropolitan Area Networks. MANs are specialized wide-area networks with very high bandwidth connections between LANs. More providers are making Ethernet connections available as an alternative to frame relay technologies.
- 10-Gigabit Ethernet. The standard for 10-Gigabit Ethernet will be finalized soon and products will be begin to hit the market. This ultra-high-bandwidth solution will be used primarily for high-end network backbones.
- Smaller servers. Servers will continue to get smaller, cheaper, and faster. Thatýs good news for corporations who want to put as many servers in as small a space as poss
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