DASS2 Converter: Background

What does DASS2 mean?

DASS2 (Digital Access Signalling System) is a BT designed signalling standard. It was introduced prior to the Q.931 standard also called Euro-ISDN. The DASS2 lines are provided to the customer on a 2Mb/s link and can handle 30 simultaneous calls of 64kb/s each.

 

DASS2 is still offered by BT and other major UK carriers. 

 

In the UK both DASS2 and Euro-ISDN lines are available to customers. Customers will normally choose the desired signalling system, as this will be dictated by their PABX. 

British Telecom announced that DASS2 has been withdrawn from new supply with effect from 10 April 2006.

 

How did Euro-ISDN evolve from DASS2?

In order to support the European Union, a common digital signalling protocol was aimed at. In 1990 the first negotiations started. The outcome was the Q.931 Euro-ISDN standard. By the end of 1993 the first Euro-ISDN installations were made. 

 

Since when does Voxtream support DASS2?

The ISDN Least Cost Router Parlay i30 was the first product from Partner Electric (the former name of Voxtream) supporting DASS2. This was in 1997. Since 2003 the Parlay i60 Protocol Converters convert between DASS2 and Euro-ISDN.