Information Technology News Archive

1996 - 2017

You are here: Home / Archives for Voice and Data Services / Network

Network

Campus Network Backbone To Be Upgraded

by

NACS has received approval to implement a major upgrade of the UCInet backbone over the next year. The backbone is the primary data network infrastructure connecting every building at UCI. The planned upgrade will address rapidly growing communication needs, and provide a foundation for ongoing departmental network improvement projects. It will ensure continued, transparent operation of the critical campus data communications infrastructure, and provide for deployment of CalREN-2, the UC-wide, high-speed regional network.

The new backbone will employ a Gigabit (1,000 Megabits/second) Ethernet fault-tolerant core to connect campus buildings at Fast Ethernet (100 Megabits/second) and Gigabit Ethernet speeds. Existing departmental networks will be connected to this core through newer, higher-speed routing and switching devices over fiber optic cable.

For detailed information, please see NACS’ Backbone Upgrade Plan in the Web:

http://www.nacs.uci.edu/communication/plans/backbone-plan-1998.html

Questions about the plan may be addressed to Garrett Hildebrand, whose e-mail address is GDH@UCI.EDU.

UCI Internet Weather Report

by

The Internet is a complex mesh of local, regional, national, and international networks linked together to behave like a single network. Your ability to access a particular network host at any particular instance depends on the status of all the networks that host’s information “packets” must traverse to reach you at UCI. The condition of networks depend on the activities of countless other network users as well as the status of a multitude of network routers and other devices. Frequently, one network or another is congested or suffering from other problems.

The network is much like the weather — some days are nicer than others, and sometimes one part of the world may be experiencing severe thunderstorms while others are basking in sunshine.

NACS has installed the “UCI Internet Weather Report” to help UCI network users get a sense of the condition of the Internet, and UCI’s connection to it. This is a web page that provides a glimpse of the “Internet Weather” at any point of time by summarizing the current “weather” between UCI and hosts on various networks around the country. The network weather is depicted as a color coded bar (green’s good, red’s bad, yellow’s in-between) determined from the amount of network data being “lost” between UCI and the remote host. This data loss is referred to as “dropped packets” and causes transmissions to be repeated until they are successfully received. These retries slow network response time.

To stay in touch with the weather (the UCI Internet weather that is) add a bookmark to the UCI Internet Weather Report:http://weather.uci.edu/

Network Addresses, Names and Name Service

by

As a network user, you may have often heard mention of terminology such as “network addresses”, “hostnames”, “DNS”, “name-servers”, “registering” your computer, and the like. If you have wondered what all the fuss was about, read below for some answers to your questions.

What is an Internet Name/Address?

Every computer connected to the network has a numeric “address” associated with it, based on its physical location. This number, also known as an “Internet Protocol (IP) address”, is used by network software to route data to the proper destination. Each computer also has a “hostname” associated with it, usually something that is meaningful to humans and indicative of the computer’s organizational relationship within the network.

For example, NACS’ orion UNIX service has a network number of 128.200.80.20, indicating it is located at UCI (128.200) and in Engineering Gateway (subnet 80). The official name of the system is “orion.nacs.uci.edu”, indicating it is associated with the NACS part of UCI. The computer could be moved to a different building with the same name, only the network address would change.

What is the Internet Domain Name Service?

The “Domain Name System” (DNS) is a world-wide distributed database system that maintains network name and address information for every computer connected to the Internet. It is among the most critical components of the network, as virtually nothing works without it. You may not realize it but you are using DNS every time you send an electronic mail message or click on a link in a web page.

How does the Domain Name Service work?

There are thousands of DNS “name-servers” around the world, each one responsible for a portion of the entire Internet “name space”. NACS is responsible for UCI’s portion of the name space, which is known as the “UCI.EDU domain”. In addition to UCI.EDU which provides network address lookups based on hostnames, UCI also manages the “reverse lookup” domain which allows a hostname to be determined from its network address.

When your network software needs to access another system, it first contacts its local name-server. If the desired system is a local UCI host, the name-server supplies the network address directly. If the host is off campus, the name-server contacts the appropriate name-servers in series to determine the network address.

Why register your computer?

It is important that your computer’s name and address be registered in DNS for several reasons. First, it will ensure that you are assigned a unique IP address. Many computer users have encountered problems due to someone else’s computer using their IP address.

Secondly, many information and service providers have restricted their host access to computers which are registered in DNS. There are unscrupulous people who use anonymous, non-registered IP addresses to “attack” hosts and cause various electronic mischief. Lastly, knowing the departmental ownership of systems allows NACS to collect overall statistics concerning network traffic, which is critical for network maintenance and planning.

How can I make sure my host is registered?

If you use NACS computer systems (EA, E4E, Orion, etc.) and are not receiving an error message about your host needing to be registered, your computer is registered. You may also check with your local computing support coordinator, who is likely in charge of registering hosts for your department. If you have further questions, drop NACS a note via our NACS@UCI.EDU e-mail address.

UCI Network Overview

by

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.

UCI CONNECTION TO VERY HIGH SPEED NETWORK (vBNS)

by

Vice President Al Gore

Vice President Al Gore

Vice President Gore announced on May 20 that the Corporation for Education Network Initiatives in California (CENIC) will receive a grant of nearly $4 million from the National Science Foundation (NSF). The grant will allow UCI and other California research universities (UC campuses, Cal Tech, Stanford and USC) to connect to the very high-speed Backbone Network Service (vBNS). UCI will gain an “OC-12” (622 mega-bits/second) network connection to participating research institutions; this connection is expected to be in place during the summer of 1998. The award is part of the Federal Government’s Next Generation Internet (NGI) initiative — a total of $12.3 million in grants to 35 research institutions across the United States was included in the May 20 announcement.

This grant will facilitate CENIC’s “CalREN-2” high-speed California network project, and will allow UCI to eventually take advantage of developments that result from “Internet-2”, NGI and other national initiatives. You may be interested in browsing some of the Web material cited below:

Network Initiative URLs:

May 20 Press release:
http://www.nacs.uci.edu/news/press-release-vbns.html

Federal Government NGI (Next Generation Internet):
http:://www.ngi.gov

CENIC (Corporation for Education Network Initiatives in California):
http://www.ucop.edu/irc/projects/CENIC.html

Very high speed backbone service:
http://www.vbns.net