# Trunk Circuit Descriptor - DID

## Purpose

The DID Trunk Circuit Descriptors form is used to assign signaling and timing parameters to groups of DID trunk circuits. This form completes the basic definition of DID trunk characteristics. The circuit descriptor numbers in this form are referred to in the Analog Trunks form.

Use this form when performing the following tasks:

- Direct Inward Dialing

- Program T1/D4 Trunks

- Program Embedded T1/D4 Trunks

NOTE: The operating characteristics for all trunks are defined by the respective trunk circuit descriptor form. There are 32 trunk circuit descriptor numbers available. These must be shared between all trunks in the system. As well, each circuit descriptor number assigned must be unique. MITEL recommends that the circuit descriptor numbers be allocated to each type of trunk in blocks. For example, CO trunks may be allocated circuit descriptor numbered 1 through 4, E&M trunks numbered 5 through 12, DS1 DID trunks numbered 13 through 21, and so on.

## Field Descriptions

Parameter | Description | Default Value
Number | Enter a unique number from 1 to 32 that is used to reference the DID trunk characteristics in the Analog Trunks form. | Blank
Release Acknowledge Timer | Enter a value between "40" and "9000" in increments of "1" unit, where 1 unit = 50 milliseconds. The range is "2000" to "120,000" milliseconds. This timer specifies the amount of time the system will wait for a release acknowledgement from the far end. | 80 units 4000 ms
Address Signalling | Select "Loop" to indicate the trunks use loop signaling or "DTMF" to indicate the trunks use DTMF signaling. NOTE: When systems are connected via T1/D4, the address signaling must match on either end of the connection. If one end is programmed as Loop and the other as DTMF, the dialed digits will not be translated by the receiving system, and the call will fail. | Loop
Incoming Start Type | Select "Wink" if the trunk is wink start on incoming calls, "Delay" if the trunk is delay dial start on incoming calls, or "Immediate" if the trunk is immediate start on incoming calls which means that digits are outpulsed immediately following seizure. | Wink
High Loss Option | Not applicable to this release. | No
Balance Network Setting | Select"600" if the load presented to the trunk port is resistive, (loaded cable, broadband system). Select "complex" if the load is capacitive (long unloaded cable). If necessary, the best option can be determined by optimizing the echo return loss as seen from an OPS or ONS connection. | 600 ohms
Trunk Category | Select "Unknown", "Short", or "Long" to indicate the trunk category. | Unknown
End of Dial and Clear Back Line Break | Enter a value between "0" and "300" milliseconds. This value specifies the duration of the End of Dial signal as well as the Clear Back Line Break signal. | 0 ms