Lucent Technologies DEFINITY Enterprise Communications Server Release 8.2 Instructions Manual

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1577 Trunks and Trunk Groups 
20
CAMA — Centralized Automatic Message 
Accounting (E911)
CAMA trunks route emergency calls to the local community’s Enhanced 911 
systems and provide Caller’s Emergency Service Identification (CESID) 
information to the system. Public Service Answering Points (PSAP) use CAMA 
trunks to determine the caller’s physical address.
NOTE:
Lucent does not recommend...

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1578 Trunks and Trunk Groups 
20
CO — Central Office
CO trunks transmit dialed digits for outgoing calls but not for incoming calls. Use 
CO trunks when you want all incoming calls go to the same destination, such as 
an attendant or a voice menu system. Individual users can place outgoing calls 
without attendant assistance. CO trunks typically connect your switch to the local 
central...

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1579 Trunks and Trunk Groups 
20
FX — Foreign Exchange
An FX trunk is essentially a CO trunk that connects your switch directly to a 
central office outside your local exchange area. Use FX trunks to reduce long 
distance charges if your organization averages a high volume of long-distance 
calls to a specific area code. 
IP Trunks — Internet Protocol Trunks
IP trunks allow DEFINITY ECS to...

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1580 Trunks and Trunk Groups 
20
Tie
Tie trunks connect a switch to a central office or to another switch in a private 
network. These trunks transmit dialed digits with both outgoing and incoming 
calls. Thus, incoming calls over a tie trunk can be routed directly to the extension 
the caller dialed. Tie trunks are frequently used in private networks; in addition, 
use tie trunks when you...

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1581 Trunks and Trunk Groups 
20
Applications for different trunk types
To help you select the right type of trunk for a specific application, the following 
table gives you an overview of key characteristics of different trunk groups. 
Remember that all analog trunks can carry only voice and voice-grade data.
Transmission and supervisory signaling
A trunk is named for its transmission...

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1582 Trunks and Trunk Groups 
20
Another transmission characteristic is signaling, which is the transmission of 
supervision, address, alerting, or other switching information. Supervisory 
signaling establishes or sets up the connection of the local switch to the distant 
switch. In general, supervisory signaling has 2 phases:
nSeizure signal — The originating office’s signal for a request...

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1583 Trunks and Trunk Groups 
20
nGround-start signaling allows answer supervision, a positive indication that 
a distant switch has disconnected from a call. Answer supervision has 2 
benefits:
— Callers who remain off-hook after completing a call won’t be 
connected to central office dial tone. For example, this prevents a 
restricted station from making an unauthorized call after placing...

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1584 Trunks and Trunk Groups 
20
nWink start — The terminating switch sends a wink start (momentary 
off-hook) signal to the originating switch. This indicates that the 
terminating switch is ready to receive digits.
nDelay dial — The terminating switch sends a delay dial signal (an 
off-hook signal followed by an on-hook signal) to the originating switch. 
This indicates that the...

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1585 Trunks and Trunk Groups 
20
and auto/wink. Signaling may be robbed-bit or common-channel depending on 
the trunk type and whether the dial-type is incoming or outgoing. The interface 
may be used to connect the switch to a toll office directly using wink-start tie 
trunks for two-way access to the toll network.
Supervision, addressing, and alerting methods have been carried over to...

DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
1586 Voice Message Retrieval 
20
Voice Message Retrieval
Voice Message Retrieval allows attendants, phone users, and remote-access users 
to retrieve Leave Word Calling (LWC) and Call Coverage messages.
Detailed description
Voice Message Retrieval is only used for the retrieval of messages. When a 
terminal is in Voice Message Retrieval mode, it cannot be used to make calls or 
access other...