Changing All the Rules
Q: How do I know how many devices to add to a network?
A: The 5-4-3 rule is used to meet the Ethernet protocol requirement that a signal sent out on the network cable reach every part of the network within a specified length of time. Each concentrator or repeater that a signal goes through adds a small amount of time. Each network is limited to a maximum of 5 segments and to connections through 4 hubs, repeaters or concentrators between any two nodes on the network. In addition, only three of the segments may be populated (trunk) segments if they are made of coaxial cable. A populated segment is one which has one or more nodes attached to it. The furthest two nodes on the network have 4 segments and 3 repeaters/concentrators between them. If there is a combination of fiber optic backbone and UTP cabling, the rule is changed to 7-6-5 rule.
Q: How is ODBC support used in access control?
A: Open Data Base Connectivity is a standard database access method that is used to make it possible to access any data from any application, regardless of which database management system (DBMS) is handling the data. ODBC manages this by inserting a middle layer, called a database driver between an application and the DBMS. The purpose of this layer is to translate the application?s data queries into commands that the DBMS understands. For this to work, both the application and the DBMS must be ODBC-compliant?that is, the application must be capable of issuing ODBC commands and the DBMS must be capable of responding to them.
In access control, it can be useful to allow transaction data, including entry, exit and system events to be shared with another application. It is sometimes easier to analyze or present data in programs such as Microsoft Access or Excel than to view the data in the pre defined reports provided by the access control system. Sharing data with other software applications is also helpful if entry and exit data from the access control system is being used to record time and attendance.
The Who, What, When
Q: What is an audit trail?
A: An audit trail is a record showing who has accessed a computer system and what operations they have performed during a given period of time. Audit trails are useful both for maintaining security and for recovering lost transactions. Most accounting systems and database management systems include an audit trail component. In addition, there are separate audit trail software products that enable network administrators to monitor use of network resources.
In access control systems, the audit trail will let you know when activities occurred and who or what caused the action to occur. For example the system might track that a door was automatically locked by the system at 5 p.m. on January 1 or that a door was temporally unlocked outside the schedule by a particular system operator. It is also helpful to know when files are deleted or archived and by whom. Another item that can be tracked is who made changes to user privileges or information.
Responsible for Monitoring
Q: Can access control systems be used to monitor events?
A: Some systems are designed to allow you to connect sensors including door contacts, motion detectors and other devices such as temperature monitors to the same equipment used to control the card readers and locks. Events can simply be recorded or they can be displayed on computer monitors to alert a guard or monitor. The monitor can be located on site or in a remote location. If the access system is used to monitor critical events, the main thing to consider is if the system will call appropriate attention to the event and also allow the person monitoring the event to record the required actions in a log for future review. What is required will depend on your customers needs.