# Measuring LS Trunk Line Settings

## Overview

Use the following tests to determine the line settings for Loop Start (LS) trunks that are connected to the AX Controller Card Chassis, Analog Main Board, Analog Option Board, or ASU II:

- Individual or Batch Line Quality Test: Reports the loss level, Echo Return Loss (ERL), and line quality for a specified trunk(s). A recommended setting is provided based on the test results.

- Individual or Batch Distortion/Echo Test: Measures the non-linear distortion effects (for example, from clipping) of a specified LS trunk(s) for each candidate balance circuit setting.

The Line Quality test allows you to obtain the optimum Balance Network Setting and Trunk Category for each LS trunk, based on the signals received from the CO. These settings are then programmed into the Analog Trunks form of the LS trunk to reduce the possibility of echo and audio level issues between the trunks and IP phones.

The Distortion/Echo test should only be run at the request of Mitel Technical Support. You can run the Loop Start (LS) Measure tests using calls between a MiVoice Business system and the CO, or by looping calls through one LS trunk on a MiVoice Business system back through other LS trunk on the same system.

NOTE: Problems with echo may occur on LS trunk lines where the maximum loss level exceeds -8 dB. Refer to your telephone service provider to ensure trunk specifications are met. If you are in the United Kingdom, Poor audio quality may be experienced if the incorrect subscriber line has been provided by the carrier. To ensure that the correct lines are provisioned in the UK, the installer or system administrator should request that the Telco (e.g. BT), or carrier, provide trunks that are compatible to System X line type '0' (Subscriber lines) or line type '3' (business PBX/PABX lines). Both types of lines will work satisfactorily with MiVoice Business, however line type '3' is the preferred line type for connecting a PBX/PABX.

## Before You Begin

The LS Measure tool is supported on systems that have a SHARC ADSP 21161N or newer DSP. To determine what card is installed in your system, check the Hardware Modules form. Under the Card Description column heading, select the SHARC Enhanced DSP card.

Before running these tests, ensure that you have

- determined if your CO provides a trunk with milliwatt or silence tone. If not, you must run the tests in loopback mode.

- configured the trunks for loopback testing if required (see below)

- determined if all LS trunks are from the same CO. For loopback, tests must be performed on LS trunks that are provided from the same CO into MiVoice Business.

- established a connection between the LS trunk line on the AX Controller card chassis, Analog Main Board, Analog Option Board, or ASU II and the local CO

- obtained the milliwatt tone number from the CO

- obtained the silence tone number from the CO

- recorded the PLIDs of the LS trunks.

NOTES

- Before you can run these tests on a trunk, the trunk must be idle. If the trunk is in use and you attempt to run the test, you will receive an error message. While a test is in progress, the system cannot use the trunk to make calls. You cannot run these tests on trunks that have been busied out.

- Only one administrator can run tests at any given time.

## Programming

### Configure System for Testing using Central Office Numbers

To run the Loop Start (LS) Measure tests by using calls between a MiVoice Business system and a Central Office:

1. Trunk Circuit Descriptor - CO form

Program the following numbers:

1. Central Office Milliwatt Telephone Number

2. Central Office Silence Telephone Number

   NOTE: If the CO uses a single number for both the milliwatt tone and silence tone, where silence is provided after several seconds of mW tone, you can use the number to obtain the silence tone. The test program automatically skips the milliwatt tone period.

2. To have system automatically apply the recommended settings from the results of the Line Quality Tests to the trunks, enable the "Auto Select" option in the Analog Trunks form. If you don't select this option, you must manually program the settings into the fields of the Analog Trunks form.

3. Configure the system to automatically email the System Diagnostic Report results from the Distortion/Echo test to Mitel Technical Support for analysis.

### Configure System for Testing using Loopback

You can run the Line Loss Level test on an LS trunk by setting up loopback through another LS trunk on the MiVoice Business system. You must program the trunks and designate one of the trunks as an answer point for the milliwatt tone.

Do not change the settings of the Trunk Circuit Descriptor until you have tested all the trunks.

To set up loopback:

1. Record the CO phone number for each trunk.

2. Program the LS trunks using the default (normal) settings for your region.

3. Program Automatic Route Selection (ARS) to allow outgoing calls.

4. System Access Points form

5. Program an unused directory number for the Milliwatt Test Directory Number.

5. Trunk Circuit Descriptor - CO form

6. Ensure that the trunk used for loopback testing is programmed with a separate Trunk Circuit Descriptor during testing.

7. Set the Trunk Category to Short.

6. Trunk Attributes form

7. Program the Milliwatt Test Directory Number as an answer point for the trunks.

8. Select the trunk service number of the incoming LS trunk.

9. Set the following answer points to the Milliwatt Test Directory Number that you programmed in the previous step:
   Non-dial In Trunks Answer Point - Day
   Non-dial In Trunks Answer Point - Night 1, and
   Non-dial In Trunks Answer Point - Night 2

7. Analog Trunks form

Program the following numbers:

7. In the Milliwatt Test Trunk Number field, enter the trunk index number of the trunk that will provide the Milliwatt tone to the trunk under test.

8. In the CO Telephone Number field, enter the CO telephone number (maximum 26 digits) of the LS trunk that you want to test.

8. To have the recommended settings from the results of the Line Quality Test applied automatically to a trunk, enable the "Automatic Setting" option in the Analog Trunks form of the trunk.

9. Make a test call using ARS, or from an external phone, to one of the trunks and verify that milliwatt tone is received.

Related Topics

- Individual or Batch Line Quality Test

- Individual or Batch Distortion Echo Test

- Line Quality Measurement

- Program Analog Trunks