Ericsson MD110 - Audio Channels between the IMC and Jessica; Trunk Line Connections and Characteristics

LBI-39039B CONFIGURATION
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3.2.1. Audio Channels Between the IMC and Jessica
The number of audio channels between the IMC and Jessica must be less than or equal to 23/30 (T1/E1). Audio channels
are available in increments of 4 channels (4 audio channels per IMC PIM audio board) up to the maximum allowed.
3.3. TRUNK LINE CONNECTIONS AND CHARACTERISTICS
A variety of trunk line connections may be used to connect the Jessica MD110 and the external switching equipment.
The MD110 supports the following types of analog and digital trunk line connections for both E1 and T1:
• CO Trunk - the most common variety of trunk used to interconnect to/from the PSTN
- supports bothway traffic
• DID Trunk - special type of CO trunk used to interconnect from PSTN
- supports only inbound traffic
- used for direct inward dialing of an EDACS radio; overdialing of radio is not required
• TIE Trunk - used to interconnect to/from another PBX
- supports bothway traffic
The MD110 supports the following trunk line characteristics:
• Loop Start - commonly used with PBX systems
- problems occur when used to carry bothway traffic. The trunk can be seized in both directions at once
and the calls collide. The MD110 questionnaire recommends that loop start trunks be converted to
ground start.
• Ground Start - minimizes call collision
- preferred type of trunk
Figure 3 shows an example of trunk line configurations used to connect Jessica to the external switching equipment.
MD110
Jessica
DISA
CO
Trunks
847-0621
847-0623
847-0625
EDACS
PSTN
Number
Mapping
DID
Trunks
528- 2000
528- 2002
528- 2001
Last 4 digits sent
Figure 3 - Example Jessica Trunk Line Configurations