# Trunk Circuit Descriptor - MSDN-DPNSS-DASSII

## Purpose

The MSDN-DPNSS-DASSII Trunk Circuit Descriptor form is used to identify the protocol characteristics of digital trunks. The characteristics are listed under a Trunk Circuit Descriptor Number. The characteristics are then associated with selected trunks by assigning the Trunk Circuit Descriptor Number to trunks in the Digital Trunks form.

NOTE: "ISDN Trunks" refer to links programmed as PRI in the Integrated Digital Access field of the Digital Link Descriptors form.

Use this form when performing the following tasks:

- Program MSDN/DPNSS 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 | A unique number (1-32) to identify the Trunk Circuit Descriptor that is referenced in the Digital Trunks form. | Blank
Card Type | The type of card installed. Options are DS1, CEPT, UNIVERSAL E1, UNIVERSAL T1, and BRI. | CEPT
Dual Seizure Priority | Specifies which trunk, incoming or outgoing, has priority in a glare situation. | Incoming
Far End Connection | Select "Main PBX". This field is not applicable for DASS II signalling. | Main PBX
Signalling Protocol | Defines the signaling protocol, DASS II or MSDN-DPNSS, to use on the trunk. DASS II is for use only in the UK. If you select DASS II, the assigned Card Type must be CEPT or UNIVERSAL E1, and the Dual Seizure Priority field must be programmed as "Outgoing". When DASS II is selected, the Far End Connection parameter is not applicable. | MSDN-DPNSS
ISDN BRI Mode | Select "NT" or "LT" when CEPT trunks are directly connected to BRI ports operating in NT or LT mode. For trunks not connected to BRI ports, leave this field blank. (NT or LT for Europe, LT for North America) NOTE: Do not set this field when programming embedded BRI trunks (through the Quad BRI Framer). | Blank