Lucent Technologies 8.2 User Manual

Issue 1

April 2000

Features and technical reference 

1171

Automatic routing — general 

DEFINITY ECS can serve as an electronic tandem network (ETN). An ETN is a 
network of privately-owned trunk and switching facilities that provide a 
cost-effective alternative to long-distance calling between locations. Each 
switching facility in an ETN has a unique private-network office code consisting 
of 1–8 digits.

Traveling Class Marks (TCM) represent the caller’s Facility Restriction Level 
(FRL) or the FRL of the caller’s access trunk group, and are sent with AAR and 
ARS numbers sent on ETNs. 

You can turn on overlap sending to work on AAR and ARS calls that are routed 
over ISDN trunk groups. Overlap sending sends ISDN call-address information 
one digit at a time instead of all the address information going out in one block. 
This significantly decreases call setup time in countries with complex 
public-network numbering plans, and is most useful for tandemed calls. See 
ISDN-PRI Trunk Group and ISDN-BRI Trunk group screens for information on 
how to set up overlap sending.

1N00

11

11

deny

fnpa

1NX

11

11

deny

fnpa

Legend:

N - 2 through 9
X - any digit (0 - 9)
deny - deny
fnpa - foreign number plan area (10-digit call)
hnpa - home number plan area (7-digit call)
intl - international
iop - international operator
op - operator
svc - service