Lucent Technologies 555-230-024 Wideband Signaling, Distributed Communications System and Isdn

Wideband Signaling

Distributed Communication System nodes are connected by tie trunks (using DS1 and ISDN-Primary Rate Interface facilities, for example). In addition, a data link is provided between the various nodes (additional equipment such as a data module may be required), offering selected feature transparency across the net- work. With ISDN-Primary Rate Interface, the data link can be configured to use either a B-Channel or D-Channel. In Figure 12-2,Telephone A calls Telephone B and then sets up a conference with Telephone C; certain system features operate as if the telephones were all on the same switch.

DEFINITY ECS’s Distributed Communication System features a sophisticated rerouting capability for optimizing trunks. Thus when you transfer out of your AUDIX voice messaging system, for example, DEFINITY ECS sets up a new path that optimizes system resources.

Distributed Communications System and ISDN

To support DCS customers who also have ISDN-Primary Rate Interface, DEFIN- ITY ECS can transport DCS messages over ISDN-Primary Rate Interface D chan- nels. As a result, you are not longer limited to private-line connections between your various locations. You can also use public network services.

Software Defined Network supports all DCS features except the following:

■DCS attendant control of trunk group access

■DCS attendant direct trunk group selection

■DCS busy verification of terminals

All other capabilities and limitations associated with the DCS still apply. This allows your company to enhance network functions by adding the benefits of

ISDN QSIG.

DEFINITY ECS also supports networking between the DCS signaling on the ISDN D channel and the DCS signaling on traditional signaling links. AUDIX systems network via DCS can also be supported over ISDN-Primary Rate Interface.

Wideband Signaling

DEFINITY ECS’s support of wideband signaling allows the system to handle applications with transmission rates greater than 64 Kbps in a single call. This includes videoconferencing, Local Area Network bridging, and other wideband applications. The system switches wideband data at N x DS0 data rates — a standard for international networking.

Systems with only narrowband capabilities typically handle wideband transmis- sions by splitting the data stream into several calls. Advantages of wideband sig- naling support include:

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