Access Control: Query the Access Control Expert

Wires and Networks Q: Do I run wires for all types of networks in the same way? A: No. Some use a bus or backbone layout, others connect to each other, and others all connect to a central point. Still others mix portions of each type to form...

A: A tree topology combines characteristics of linear bus and star topologies. It consists of devices arranged as a tree in groups of star-configured devices connected to a linear bus backbone cable. It is a common method used to expand local area networks.

The point-to-point wiring of individual segments makes it easy to expand a tree topology network. The overall length of each segment is limited by the type of cabling used. If the backbone line breaks, the entire segment goes down.

Brad Shipp is a former Executive Director and Training Director for the NBFAA where he authored several NTS courses, including the Access Control Certification course. His involvement in the access control industry dates back to 1974 and in 1986 he became an instructor for the NBFAA National Training School. Shipp has served on several law enforcement, regulatory and industry association boards and has been honored for his service by the False Alarm Reduction Association and the International Association of Security and Investigative Regulators. Send in your questions on access control to