MULTI-STATION BACKUP FOR MAIN/STANDBY
Original Publication Date: 1998-Mar-01
Included in the Prior Art Database: 2002-Jun-27
The MAIN/STANDBY feature uses one station to "backup" another station in case of failure. The STANDBY station is required to have the contigu- ration information (Personality codeplug) identical to the MAIN station loaded prior to installation. Currently, the Conventional MAIN/STANDBY feature, as implemented in the Quantar station, uses a number of status lines on the 50 pin TELCO punchblock and Enhanced WildCard in a two station configuration. Each station uses WildCard to gather information on the other station's health; the information is passed between the stations using the status lines. The STANDBY station uses WildCard to assess the health of the MAIN station thru the status lines. When a failure occurs in the MAIN station, the STANDBY station changes its mode of operation from STANDBY to MAIN and thus provides backup for a single Conventional station. In large Conventional systems, where multiple channels are used, one station is used for each channel. If it is required to have a backup for all the channels, then each of the active stations in the system will require a dedicated backup station. This configuration becomes a very expensive fault- tolerance solution for large Conventional systems.