# Private Line Automatic Ringdown

## Description

The Private Line Automatic Ringdown (PLAR) feature provides rapid connections for Mitel 5560 IPTs used by securities and commodities traders. When a trader goes off-hook on a PLAR trunk, the device at the other end automatically rings without the need for dialing.

PLAR trunks are T1 or E1 links that use modified (inverted bit) Channel Associated Signaling (CAS) over E&M trunks. To work properly, this feature must be configured in the same manner at both ends of the connection.

## Conditions and Feature Interactions

- PLAR trunks are supported for T1/E1 links on the T1/E1 Combo MMC and the T1/E1 Dual Framer MMC.

- Support for PLAR on E1 links is limited to systems with 3300 ICP Release 8.0 or higher software.

## Programming

1. Class of Service Options form

- Set the Individual Trunk Access field to "Yes".

- Set the ANI/DNIS/ISDN Number Delivery Trunk field to "No".

- Set the Ringing Timer to 5 secs to ensure failsafe operation.

- (Optional) Enable "Privacy Released" to allow other sets in the same key system group to enter a call in progress on the DTS line by pressing the busy DTS key.

- (Optional) Enable "Ringing Line Select" to automatically answer a ringing DTS line when the handset is picked up.

- (Optional) Set Disable Conference Join Tone to "Yes" to disable the tone that users hear when a conference call is established.

- (Optional) Set Disable Executive Busy Override Tone to "Yes" to disable the tone that all parties in a call hear when a user initiates Executive Busy Override.

- (Optional) Enable "Auto Release on Key Select" in the user's COS to automatically disconnect a call in progress when the user answers another line.

2. Digital Link Descriptors form

- Enter "T1D4" or CEPT CAS (for E1 links) in the Integrated Digital Access field.

3. Trunk Circuit Descriptor - Digital E and M form

- Select "Immediate Start" from the Incoming Start Type and Outgoing Start Type fields.

- Set "AB Signalling Bit Inversion" to Yes.

- Select "Loop" from the Address Signalling field.

- To ensure proper trunk release when the far end disconnects, either set Ignore Far End Disconnect to "Yes" (recommended) or set the Guard Timer to 6000 ms.

- Set the "Far End Disconnect Not Required Before Initiating New Call" and "Ring Until Answer" options as required.

4. Digital Trunks form

- Assign a DTS Trunk Service number to the PLAR trunk.

5. Multiline Set programming

Multiline Set Keys form

Program a DTS key as follows:

6. Line Type: set to "Single Line" or "Key System" depending on the number of DTS keys that the trunk appears on.

7. Button Directory: enter the four digit trunk number proceeded by 'T'.

8. Ring Type: set to "Ring" if ringing notification is desired.

6. Single Line Set programming

- Program the set as a hotline and set the answer point to a system speed call number that dials the hunt group number of the PLAR trunk.

## Device Support

5560 IPT

## Operation

### Multiline sets

To initiate a PLAR call:

- Go off-hook and press the key programmed for direct trunk select of the PLAR trunk.

### Single line sets

To initiate a PLAR call:

- Lift the handset.