Telephone companies serving rural areas can now use Common Channel Signalling System 7 networks at a greatly reduced cost, says Northern Telecom Ltd, which has just launched its DMS-10 Signalling Relay Point. Signalling System 7 is an intelligent network architecture which uses out-of-band signalling for call set-up and routing. The new DMS-10 funnels messages from a sub-network of CCS7-equipped exchanges into pairs of Signalling Transfer Points which provide routing through the CCS7 network. A single Signalling Relay Point can support a cluster of up to 19 exhanges and cut the required number of Signalling Transfer Point access links from 38 to two. The cost of these access links from central offices can amount to $5,000 a month Geneseo Telephone Co of Geneseo, Illinois, which has been testing the system, reckons it has been saving $24,000 a month, having cut out 12 access links. The Signalling Relay Point can be deployed on an existing DMS-10 exchange or as a stand-alone network element, and the exchange, which houses the Signalling Relay Point – can continue to serve as end exchange switching lines and trunks, as well as serving the Signalling Relay Point functions. DMS-10 supports analogue and digital links of 4.8Kbps to 56Kbps and is application-independent. It will support any vendors’ exchange in the subnetwork, where the CCS7 connections meet Bell Communications Research standards.
