With the growing utilization of electronic communication in all aspects of University affairs, the campus network (UCInet) has become a critical campus asset. As communication needs continue to grow and change, the network must be maintained and enhanced to keep up. This requires a substantial campus investment. To facilitate discussions, NACS seeks to broaden campus understanding of network issues and options. Toward that goal, this article summarizes the layout and important components of UCInet. Subsequent articles will address current performance issues and planned improvements to UCInet.
UCInet may be logically grouped into six fundamental components, as follows:
1. Departmental and organizational LANs (Local Area Networks);
2. The campus backbone;
3. Network services;
4. WAN (Wide Area Network) connections;
5. Internet connectivity;
6. Remote access (e.g., modems and related equipment)
Departmental LANs, which connect to the backbone via devices known as routers, may be viewed as the “edges” of the network. UCI has a diverse collection of LANs. Most operate as “shared Ethernet”, meaning that connected computers “take turns” utilizing the network’s 10 Mbps (Megabits Per Second). LANs provide communication between computers within departments, and the routers they connect to provide links to the campus backbone and the services UCInet supports.
The UCInet backbone is the binding tie that connects LANs, the Internet, and other networks, such as the UCI Medical Center. It may be viewed as the “core” of the network. UCInet’s backbone has about fifty routers, each with multiple interfaces, for a total of about 350 LAN interfaces on campus.
“Network services” are computer-based services required by all users of the network. One example is the campus Domain Name System (DNS) servers, which provide translation of network names to network addresses. Applications such as Netscape cannot connect to a Web site until a DNS server answers a query for translation of a domain name to an Internet address.
Network services operate behind the scenes and are transparent to users. When a Web server fails to connect to a Web site, a user cannot distinguish between a network outage and a bad DNS lookup. In fact, one may cause the other!
UCInet has several WAN links to support outlying campus facilities. These links allow network users at sites like the Medical Center to appear as if they are on campus, albeit at slower speeds. “T1” (1.5 Mbps) WAN links are six times slower than the standard 10 Mbps Ethernet now widely in use.
Internet connectivity is provided throughout UCInet from another network called UCnet, which connects all UC campuses together. UCnet currently operates at a speed of 10 Mbps. However, UCI and UC Berkeley connect to UCnet and the Internet at “T3” (45 Mbps) speeds, as they are the UCnet network access points for the Internet.
Remote access to UCInet is accomplished via the campus modem pool and the Internet. Users may dial-in to UCInet through the modem pool or access UCI systems through their own Internet Service Provider.
UCInet is a diverse collection of networking and computing technologies which supports over 14,000 computers, printers, hubs, routers and other network devices, plus several hundred dial-in connections and countless visits from the Internet. In our next NACS-News network article, we will discuss UCInet’s most significant performance issues.