DAR was implemented in the BT trunk network at the end of March 1996 and now covers 75% of BT's geographic number ranges, with 100% coverage planned for September 1996. The possibility of extending its use to other number ranges is under investigation.
Early indications are that DAR is being used even under stable network conditions and is responding well to short term traffic fluctuations. For example on 1 April, 8225 DAR routeing choices were made with a 99.3% success rate.It will not be possible to assess the full benefit of DAR until we experience a major network failure with DAR.
The main benefit of dynamic routeing strategies, such as DAR, is their ability to terminate calls that would otherwise fail due to network congestion, protecting revenue and improving customer perception. DAR is simpler to manage, more robust and uses less processor effort than other more complex dynamic routeing strategies.
(Barry Jackson, BT)