Instruction manual

DEFINITY® Business Communications System and GuestWorks® Issue 6
Overview
555-231-208
Issue 1
April 2000
Networking Solutions
9-5Network management features
9
Subnetwork Trunking
Subnet Trunking modifies the number dialed so an AAR or ARS call can route
over different trunk groups that may terminate in switches with different dial plans.
Subnet Trunking inserts digits, deletes digits, pauses, and/or waits for dial tone in
digit outpulsing, as required, so calls route as follows:
■ To or through a remote switch
■ Over Tie trunks to a private network switch
■ Over CO trunks to the serving CO.
Subnet Trunking is required on calls routing to or through a remote switch,
regardless of the call’s destination.
Generalized Route Selection
Generalized Route Selection gives you the capability to not only select the optimal
call routing based on the dialed number, but also to select the appropriate facility
based on the type of call. Generalized Route Selection enhances Automatic
Route Selection and Automatic Alternate Routing by incorporating additional
parameters such as the type of call to be used in deciding how a call is to be
routed.
Different types of calls require the use of different types of facilities. For example,
high-speed data calls must use digital facilities, whereas voice and voice-grade
data calls can use either analog or digital facilities. The system uses Generalized
Route Selection to differentiate between these and other types of calls and route
them on the appropriate trunks. Based on the call types and available trunk facili-
ties, voice and data calls may be routed over different trunk types or integrated on
the same trunk group. The system also provides the capability to route calls
based on the data format and the need for restricted or unrestricted facilities.
To select the appropriate trunking facility for a call, the system must know the type
of call being made. To do this, each originating facility such as a telephone or data
module has a bearer-capability class assigned. Some originating facilities, such
as data modules, may have multiple bearer-capability classes. Each trunk group
in the routing pattern is assigned a list of allowed bearer-capability classes. When
a user makes a call, the system queries the originating facility for its bearer-capa-
bility class and then tries to route the call on a trunk group with a bearer-capability
class that matches the bearer-capability class of the originating facility. If an exact
match is not found, the system then tries to find a trunk group with a compatible
bearer-capability class.
Since the system automatically chooses the right trunk based on the administra-
tion, the system’s dial plan can be independent of the type of call being dialed.
Users do not have to worry about dialing a different access number for different
call types.