Progress on The HKU Gigabit Ethernet Campus Network

In a previous issue of the Computer News,  we had informed readers about the implementation of the Gigabit Ethernet (G.E.) Campus Network backbone to augment the existing ATM backbone network. To recap, two high-density G.E. backbone switches with routing capability were installed last October to serve as the new G.E. backbone. One of the two switches is installed in Computer Centre and the other is in the Kadoorie Biological Sciences Building. These two systems are running in parallel and are each other's backup system in case one of them fails.  Each G.E. backbone switch has an ATM OC-12 (622Mbps) link to connect to the existing ATM backbone network.

During the last few months, Computer Centre has been working on this network upgrade project. Currently, network traffic on the old backbone routers had been re-routed to the new backbone to off-load the old backbone routers. After all the new fiber connections between buildings in the main campus were ready at the end of January,  we proceeded to install high-density Fast Ethernet (F.E.) switches into various buildings in the main campus. The F.E. switch is to serve as a building concentration switch for that building, and each F.E. switch has dual G.E. fiber uplinks to connect to the G.E. backbone. The F.E. switches were installed in the following buildings:

All the hardware configuration and installation work of this project is completed. The next phase of this project is to connect the network segments in each of the buildings to the newly installed  F.E. switch. We will further inform readers about the progress in later updates.


Asynchronous Transfer Mode

ATM (asynchronous transfer mode) is a dedicated-connection switching technology that organizes digital data into 53-byte cell units and transmits them over a physical medium using digital signal technology. Individually, a cell is processed asynchronous relative to other related cells and is queued before being multiplexed over the transmission path. Multiplexing is sending multiple signals of information on a carrier at the same time in the form of a single, complex signal and then recovering the separate signals at the receiving end. Our ATM backbone has a transmission speed of 622 Mbps.

Gigabit Ethernet

Gigabit Ethernet (GE) is a local area network transmission standard that provides a data rate of 1 billion bits per second (one gigabit). Existing Ethernet LANs with 10 and 100 Mbps cards can feed into a Gigabit Ethernet backbone.

Fast Ethernet

Fast Ethernet is a local area network transmission standard that provides a data rate of 100 megabits per second (100BASE-T). Workstations with existing 10 megabit per second (10BASE-T) ethernet cards can be connected to a Fast Ethernet network.


Ethernet is the most widely-installed local area network (LAN) technology. A local area network (LAN) is a group of computers that share a common communications line and the resources of a single processor or server within a small geographic area (e.g. within an office building).  An Ethernet LAN typically uses coaxial cable or special grades of twisted pair wires providing transmission speeds up to 10 Mbps (10BASE-T).

Ronald Leung
Tel: 2857 8593

[Previous] [Contents] [Next]