3. Network-based Services

Apart from the basic functions of the network described in section 2. Network Infrastructure above, a wide variety of key infrastructural network services are also provided by OUCS. These are used by all sectors of the University, some consciously but others unconsciously in the background. These services include:
  1. Domain Name Server (DNS)
  2. Email relay server
  3. Network time server
  4. Dynamic Host Configuration Protocol (DHCP) service
  5. Web cache
  6. Web servers
  7. Email POP and IMAP servers
  8. Network News server
  9. Mailing List server
  10. File backup and archive server (Hierarchical File Store) (HFS)
  11. Windows Internet name server
  12. Novell Directory Services (NDS) tree server
  13. Virtual Private Network (VPN) server
Most are based on PC equipment running Linux, with a few using Sun equipment running Solaris. The choice is determined by the requirements of the application software, though the PC/Linux solution is preferred (for cost and supplier-independence reasons) where feasible. Typically, all require and exhibit very high reliability.
In addition to the above computer-based services, other key network services provided more directly by staff include:
  1. Oxford Emergency Computer ResponseTeam (OxCERT)

  2. Ethernet Maintenance service

Details of all these services can be found on the OUCS Web pages at ??. Several of these services are discussed in more detail below.

3.1. Email Services

3.1.1. Email Relay

The Email Relay service handles the vast majority of the University's incoming and outgoing email (some departments operate independently). It also handles inter-system email within the University. It directs email to the appropriate email server, performs address checks and rewrites addresses to the standard form (where requested by the relevant department to do so), handles distribution of multiple-recipient email, `spools' email intended for non-responding recipient systems, etc. The number of messages handled during the year approached 150,000/day on average [figure Figure 7, Daily Average Numbers Through Email Relay], with the volume of traffic amounting to nearly 3,000 Mbyte/day on average [figure Figure 8, Mean Daily MBytes Delivered by Email Relay], 50% larger than last year. Both the volume of messages and the size of each message continue to rise inexorably.

Daily Average Numbers Through Email Relay
Figure 7. Daily Average Numbers Through Email Relay
Mean Daily MBytes Delivered by Email Relay
Figure 8. Mean Daily MBytes Delivered by Email Relay

3.1.2. Herald Email Server

There are now 22,500 users of Herald. Performance and availability remain excellent.

3.2. Mailing List Service

The Mailing List service is provided by a dedicated PC running Linux. It uses the public domain Majordomo software, and manages over 900 lists. Support and encouragement for the national Mailbase service (which in total handles 3,000 mailing lists) is also provided.

3.3. General Web Server

Hits on the general-purpose web server [figure Figure 9, OUCS Web Server Hits per Week (millions)] continue to grow, with a 50% increase compared to last year. It serves 110 domains — mostly colleges and departments within the University, with addresses of the form `www.department.ox.ac.uk'. It holds the home pages of 2000 users, and holds 156000 web pages in all, totalling 14 Gbytes of data. The OUCS web pages were moved during this year to a dedicated server.

OUCS Web Server Hits per Week (millions)
Figure 9. OUCS Web Server Hits per Week (millions)

3.4. Backup and Archive File Server

The Hierarchical File Server (HFS) project was started in 1995 to provide large scale central filestore services to the University community. The HFS runs software called Tivoli Storage Manager (TSM, formerly known as ADSM). The two main services provided by the HFS are (1) Desktop and Departmental/College Server backup service [figures Figure 10, HFS totals for backup (data) & Figure 11, HFS totals for backup (files)] and (2) long term data repository service for university digital assets [figures Figure 12, HFS totals for archive (data) & Figure 13, HFS totals for archive (files)].

Since the original procurement of the HFS computer systems, we have instigated a rolling programme of upgrades of the principal hardware components (IBM RS6000 computers, an IBM 3494 Automated Tape Library and 3590E tape drives) which has kept the system capacity ahead of demand. The M80 was installed in August 2000 and runs two TSM servers, for the server backup service and for the long term archive service. Prior to that the entire backup service was running on the H70; the H70 now provides the desktop backup service. Both RS6000s have performed very well throughout the year.

The figures [Figure 10, HFS totals for backup (data) & Figure 11, HFS totals for backup (files)] show both backup services combined as `desktop' in August 2000; as the servers were transferred to the M80 there is an apparent drop in desktop usage as data was deleted from the H70. By the beginning of 2001, the transfers were largely completed and the figures show both services increasing since then. The `server' service is showing the fastest rate of increase. The totals for both backup and archive continue to grow.

The site-wide backup service continues to offer a highly reliable and available facility with great convenience and simplicity to the end user.

Oxford hosted a second TSM Symposium in September 2000 which attracted about 170 attendees, mostly from Europe but there were also users and TSM developers from the USA present.

HFS totals for backup (data)
Figure 10. HFS totals for backup (data)
HFS totals for backup (files)
Figure 11. HFS totals for backup (files)
HFS totals for archive (data)
Figure 12. HFS totals for archive (data)
HFS totals for archive (files)
Figure 13. HFS totals for archive (files)

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