The Network Services Section

Sixth in the Series...

[icon] In the previous five issues, we have already described the roles played by five functional units within the Computing Services Centre, namely, the Information Services Section, the Administration Data Processing Section, the Academic Services Section, the Technology & Planning Section, and the Systems Services Section. Hopefully by now, our readers would have an idea about the day-to-day operations of our Centre and would also know where to obtain useful resources when needed. In this issue, we shall look at the Network Services Section, a team of experts who have been working extremely hard behind the scenes to maintain the stability of the increasingly overloaded campus network - CTNET. Let us now take a closer look at how and what different tasks are divided among the team members and the difficulties they had encountered over the years in resolving various problems concerning our computer network.

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The Network Services Section

C.Y. Kwok

Objective and Scope of Service

The Network Services Section (NS) maintains and supports the City University Campus Network (CTNET), all staff and student LANs, as well as all the off-campus connections such as HARNET, Internet, modem pools, etc. The main objective of NS is to keep the network up and running and to ensure it has adequate bandwidth to meet most users' needs.

Organization

There is a total of 9 staff in NS, including the Systems Manager who is in charge of the Section. They can be roughly divided into 4 major groups according to the following support areas:

Network backbone and off-campus connections - 3 staff
Staff LANs - 3 staff
Student LANs - 2 staff
E-mail and client-server - 1 staff

Considering a network with more than 4,200 connected systems, the manpower of NS is barely adequate.

Network Backbone

The campus backbone consists of mainly a FDDI ring and over 40 thick Ethernet segments, which are interconnected together using networking devices such as switches, routers, bridges and repeaters. Support staff in this area are responsible for designing and maintaining the network infrastructure of the entire campus. This includes designing the layout of network cabling, managing all the networking devices, monitoring the network traffic, allocating network addresses, troubleshooting network connectivity problems, etc.. They are also heavily involved in formulating plans for the future network upgrade and evaluating new network technologies in collaboration with the Technology and Planning Section. A network pilot scheme has just been started to find the best solution for a major network upgrade.

Off-campus Connections

Such connections include a T1 circuit to HARNET/Internet, connections to H.K. Datapak Services, incoming and outgoing modem pools, and home PC connections. Support staff in this area manage all the routers, gateways, servers, a PABX and modems, which are used for supporting these connections. They also configure and manage the university-wide domain database of cityu.edu.hk, coordinate with a few departments to set up their own domain name servers and databases for putting up their own information on the Internet. Support staff actively cooperate with other HARNET Technical Group members to monitor the performance of HARNET (the link to the other member academic institutes) and its Internet link and work together to resolve all the technical issues. As a result of such cooperative effort, the HARNET Internet link has been successfully upgraded from 128Kbps to T1 speed. This improvement has already been announced earlier in Issue No. 4 of Network Computing under "Internet Link Upgrade". Furthermore, support staff keep close contacts with a number of universities in mainland China in sharing experience on data communications and networking. Specifically, NS staff have provided technical assistance to Tsinghua University in its CERNET (China Education and Research Network) project.

Staff LANs

Three staff are dedicated to support Digital Pathworks which is the network operating system in use by all staff on a departmental LAN. All NS staff provide support to Pathworks in some way as the Computing Services Centre (CSC) views such support as vital to all staff. Over 2,000 staff PCs are running Pathworks currently. This number keeps increasing despite that some staff PCs have been changed to run Windows 95 and Netware, etc. Both Pathworks versions 4 and 5 co-exist on our staff LANs. Pathworks version 4 uses a OpenVMS VAXstation as the server which is installed and managed by the Systems Services Section. After the upgrade of the client software to Pathworks Version 5, the departmental servers have been switched to a different platform with Pentium PC running Windows NT Server software which is installed and managed by NS. NS staff in this area are responsible for supporting the Pathworks client boot disks, tuning the performance, and maintaining the connectivity of all the file and print services.

Student LANs

Currently, over a thousand student PCs are running on the Novell Netware network operating system, about half of which are located in the CSC. Two NS staff are dedicated to support these PCs as well as over 30 Netware servers. They are responsible for the installation and maintenance of the Netware server software, as well as the creation and maintenance of Netware accounts, file and print services etc. They also support all the Netware client boot disks and the TCP/IP software in use by all the clients.

E-mail and Client-Server

E-mail is an indispensable tool for all network users nowadays. Most staff use the central VAXcluster (now ALPHAcluster) for e-mail while most students use the POLYLINK machine (an ALPHA) for the same purpose. One NS staff is dedicated to support the underlying E-mail software used on all these systems.

The staff is responsible for the configuration of the e-mail software, monitoring the mail queues, solving e-mail connectivity problems, and performing tedious tasks of a postmaster. The staff also takes part in various task forces which are set up within the CSC to study and evaluate different client-and-server based applications such as e-mail, office automation, database access, etc.. Since the trend is to move towards client/server applications, the NS section will assist in shifting our administrative systems to a client/server mode of operation. This may also involve resolving integration problems during the transition period.

Interactions with Other Sections

NS works closely with all the other Sections because all the services provided by CSC are network related.

Major Challenges

Management Difficulties

Since this university adopted a decentralized approach regarding equipment acquisition, the campus network has gradually become unmanageable. The main reason is that there is no clear boundary between a department's network and the campus network backbone and a department tends to connect any number of devices to the network at will regardless of the capacity of network bandwidth. It comes to a situation in which some departments have their own network support staff and these staff manage devices on the same network segment as those managed by CSC or some other departments. On many occasions, network problems arise as a result of illegal network connections made by departments without prior coordination with CSC. This situation gets even worse when compounded with the frequent additions and changes of network connections due to reallocation of office areas. Despite that the CSC has devised a comprehensive network policy for all departments (including the CSC) to follow, most of the time it could not be enforced.

Technical Difficulties

As user demand on network bandwidth is ever increasing, the NS section has to select carefully a mature and stable technology among the new fast growing network technologies. The current network does not have the infrastructure to cater for ad hoc changes because there are some limitations in the campus buildings which prohibit the installation of a structured wiring system. For example, the under-floor trunking systems are too full for wiring UTP cables, and communication closets are too small to house the network hubs and networking devices. The proliferation of plug-and-play systems such as Windows 95s and NTs on the network creates a lot of broadcast messages which affect the performance of the whole network. No filtering can be done on the broadcast messages because most network segments are shared by more than one department. As such, our campus network turns out to be the most difficult one to manage amongst the local universities.

The Future

Although the CSC will try its best to solve most of the current network problems by introducing high speed switching and virtual LAN technologies, the future of this network largely relies on the close cooperation of all departments, good coordination and planning on office relocation and on changes of network requirements, and the direct support from the top management of this university. As technologies keep evolving, network upgrade is going to be a continuing process. The CSC must be empowered to ensure that the network policies are observed and it should be given sufficient resources to carry out a major network upgrade. A good university cannot maintain its status without a good network.

[Issue No. 6]

Computing Services Centre
City University of Hong Kong
ccnetcom@cityu.edu.hk

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