Instruction manual

DEFINITY® Business Communications System and GuestWorks® Issue 6
Overview
555-231-208
Issue 1
April 2000
Networking Solutions
9-7Network interfaces and equipment
9
Network interfaces and equipment
The system supports a variety of interfaces to voice and data networks. Trunks
supply links between the system, the public network, and other systems. Digital
Signal Level 1 interfaces offer high-speed digital connectivity between systems.
For a complete listing of the trunk and line interfaces available in different
countries, see the
DEFINITY
®
ECS System Description .
Trunk group circuits
Trunks provide the communications links between systems, including central
office switches and other premises switches. Trunks that perform the same
function are grouped together and administered as trunk groups. Trunks interface
with the system via port circuit packs. Trunk group circuit types include the
following:
■ Local exchange trunks
■ Tie trunks
■ Auxiliary trunks
■ Digital trunks.
Local exchange trunks
Local exchange trunks connect the system to a central office. The following are
some of the types available:
■ Central office trunks which connect the system to the local central office for
incoming and outgoing calls
■ Foreign exchange trunks which connect the system to a central office other
than the local one
■ Wide Area Telecommunications Service trunks which allow you to place
long-distance outgoing voice-grade calls to telephones in defined service
areas; these are priced according to distance in the service area, length of
the call, time of day, and the day of the week
■ Toll-free service trunks (such as 800 and 888) which let your business pay
the charges for inbound long-distance calls so that callers can reach you
■ Direct Inward Dialing trunks which connect the system to the local central
office for incoming calls dialed directly to stations without attendant
assistance
■ Digital Service 1 trunks which can be used to provide T1 or ISDN Primary
Rate Interface service.