Contact
Michael Cheung
Austin Joe
Mike van Abbema

Supervisor
Dr. Eric Manning


Future Considerations

1. Token Ring

Instead of using CSMA/CD (Ethernet) connectivity between the three components of our system we can improve the reliability by implementing token ring technology. In token ring technology the network uses a special frame called a token that rotates around the ring when no stations are actively sending information. When a station wants to transmit on the ring, it must capture this token frame. The owner of the token is the only station that can transmit on the ring, unlike the Ethernet topology where any station can transmit at any time. Once a station captures the token, it changes the token into a frame format so data can be sent.

As the data traverses the ring, it passes through each station on the way to the destination station. Each station receives the frame and regenerates and repeats the frame onto the ring. As each station repeats the frame, it performs error checks on the information within the frame. If an error is found, a special bit in the frame called the Error Detection bit is set so other stations will not report the same error.

Once the data arrives at the destination station, the frame is copied to the destination's token ring card buffer memory. The destination station repeats the frame onto the ring. The frame continues around the ring, arriving back at the source station who recognizes the sending address as it's own. The frame is then stripped from the ring, and the source station sends a free token downstream.

Advantages:

  • No collisions
  • No retransmitted packets due to collisions
  • No flooding
  • Ring loading is easily estimated by scan time
  • Fault tolerance can detect path breaks and recover
  • Multiple paths are possible

Disadvantages:

  • More expensive than Ethernet
  • Less common in the technological world

2. PHP

PHP is a scripting language that is especially suited for Web development and creating dynamic Web pages. It can be easily integrated into HTML. This would make it suitable for use within the Monitoring Station.

PHP contains a set of functions that can be used for socket programming. These functions are similar to the socket functions found in the C programming language. These functions have been designed to work equally well on Windows and UNIX machines.

As well, PHP is also known for its compatibility with the MySQL database server. Large systems will require a database to store information and PHP in conjunction with MySQL would be able to retrieve that data easily.

Advantages:

  • Ease of integration with HTML
  • Compatibility with MySQL

Disadvantages:

  • Socket functions are still in experimental stage

Updated: July 27, 2004