September 1997
Volume 1, Issue 2
 
Inside this Issue... 

Instructional Computing Room Opens 

Course Library 

Pathworks (DOS and Windows 3.1) Wind-down 

Web-based Data and Information Services 

Undergraduate Computing Accounts 

SSC Network Upgraded to Fiber Optic Backbone 

Social Science Computing Services 

SSC Network Help Notes 

Scan Exam 
 

Social Science Computing Laboratory 
Faculty of Social Science 
Room 1228, Social Science Centre 
The University of Western Ontario 
London, Ontario, Canada, N6A 5C2  

E-mail: ssts@uwo.ca 
Web: ssts.uwo.ca  
Phone: 519 661-2152  
Managing Editor: Les Flodrowski 

  

SSC Network Update

SSC Network Upgraded to Fiber Optic Backbone

Steve Rumas 

Over the summer months the backbone of the SSC Network was upgraded from copper-based coaxial cable, which provided a standard Ethernet network communications speed of 10Mbps (million bits per second), to fiber optic cabling providing Fast Ethernet communications speeds of 100Mbps. The old cabling system, originally installed in 1988, blocked our ability to use faster network topologies such as 100Mbps Fast Ethernet or ATM and severely restricted growth of the network. Additionally, fiber optic cable is impervious to electrical noise, provides more reliable communications, and gives us the ability to use even higher speed topologies in the future. 

To allow for future growth of the network, multiple fiber trunks were run from the four primary wiring closets in the building to a new central switch located in the SSCL machine room. This new switch, a 3Com Corporation CoreBuilder 5000, replaced the previous one to provide a faster, more powerful and flexible central switch for the faculty.  The CoreBuilder 5000 can accommodate connections to multiple network architectures such as Ethernet, Fast Ethernet, Gigabit Ethernet and ATM. It can also handle 30 to 40 fast Ethernet connections and allowed us to implement 100Mbps communications pathways to: 

  • SSCL’s 3 Microsoft NT servers (serving Windows 95 workstations)
  • SSCL’s Unix-based Web server
  • New Ethernet/Fast Ethernet switches placed in each of the four main wiring closets in the SSC building, plus one in SSCL to provide connectivity to computing resources located within SSCL.
As mentioned above, new Fast Ethernet/Ethernet switches were placed in each of the main wiring closets. The faculty/staff user community was broken up into groups of 11 or 12 user workstations. Each group communicates with the backbone over a shared 10Mbps Ethernet segment connected directly through the switch to the 100Mbps fiber trunk.  This new arrangement minimizes traffic congestion to private offices since workstations now contend for access to the network with only 10 or 11 other systems before network requests are placed directly on the high-speed fiber trunk. Under the old scheme, up to 100 workstations were connected to a main wiring closet and competed for use of a much slower 10Mpbs Ethernet segment. 

It should also be noted that cross-talk problems were discovered in some twisted pair connections to individual offices in the east-end of the building. Cross-talk produces degraded network performance between workstations and the Faculty backbone.  To remedy the problem, newer Category 5 cabling has been run to these offices. Once these new cables are terminated in the offices, they will be activated.  All should be functional by the end of September. 

In conclusion, the new cabling plant and switching hardware will allow the network to sustain high performance as it grows with acquisition of additional workstations and faster servers.