Trunk Circuit Descriptors - E&M

Purpose:

The E&M Trunk Circuit Descriptors form completes the basic definition of E&M trunk characteristics. With this form, trunk signaling and timing parameters are set for groups of E&M trunk circuits. The circuit descriptor numbers in this form are referred to in the Trunk form. To complete this form, select the required values under each circuit descriptor number.

Use this form when performing the following tasks:

 

Field Descriptions

Parameter

Description

Default Value

Number

Enter a number to uniquely identify each entry.

 

Release Acknowledge
Timer

Enter a value between "40" and "2400" in increments of "1" unit, where 1 unit = 50 milliseconds. The range in milliseconds is "2000" to "120,000". This timer specifies the amount of time the system will wait for a release acknowledgement from the far end.

80 units (4000 ms)

Address Signaling

Select "Loop" if loop signaling is used by the trunk, or  "DTMF" if DTMF signaling is used.

  • 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

Disconnect Timer

Enter the duration of the disconnect signal timer. Allowed values are from "150" to "300" milliseconds, in 50 millisecond increments. This value defines the minimum acceptable duration of a disconnect signal from the far-end. This timer must be longer than the Flash Timer.

300 ms

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

Dial Tone on Incoming Seize

Select "Yes" if dial tone is to be returned by the PABX when the trunk is seized by the far-end. Select "No" to indicate that dial tone will not be returned on a seize.

No

Minimum Flash Timer

Enter a value between "100" and "250" milliseconds, in increments of 10 seconds, to define the minimum flash time required in order for the peripheral software to detect a recall.

250 ms

Maximum Flash Timer

Enter a value between "200" and "800" milliseconds, in increments of 10 seconds, to define the maximum flash time required in order for the peripheral software to detect a recall.

200 ms

Outpulse Delay Timer

Enter a value between "100" and "2000" milliseconds, in increments of 50 milliseconds, to define the duration of the delay before outpulsing commences after a seizure.

  • Note: Outpulsing could commence several hundred milliseconds after the programmed duration. Only the minimum duration is guaranteed.

800 ms

Outgoing Start Type

Select "Wink" if the trunk is to provide wink start signaling on outgoing calls, "Delay" if the trunk to provide delay dial (without integrity check) signaling on outgoing calls, or "Immediate" if the trunk is to provide immediate signaling on outgoing calls or the circuit is to be used as a Music On Hold input. Select "Delay Integ" for delay dial with integrity checking to indicate that the system must wait for a delay dial signal from the far-end before outpulsing. When an E&M Trunk Circuit is used as a Music On Hold input, ensure the "Outgoing Start Type" field is programmed as "Immediate".

Wink

Supervision Timer

Enter the duration of the Supervision timer. Values range from 200 to 12750 ms, and are calibrated in 50 ms increments. 200 to 1000 milliseconds applies to "Immediate" trunks. 200 to 12750 milliseconds applies to wink start trunks. 4500 to 12750 milliseconds applies to Delay Dial and Delay Dial with integrity check trunks. This timer specifies the expected duration of a supervision signal from the far-end.

200 ms

Maximum Wink Timer

Enter the maximum duration of the wink timer. Values range from 300-4000 ms, and are calibrated in 50 ms increments. 300 to 450 milliseconds applies to immediate, wink start and delay dial trunks, and 300 to 4000 milliseconds applies to delay dial with integrity check.

400 ms

Minimum Wink Timer

Enter a value between "50" and "150" milliseconds, in increments of 50 milliseconds to define the minimum duration of the wink timer.

100 ms

Guard Timer

Enter a value between "100" and "6000" milliseconds, in increments of 50 milliseconds to define the duration of the guard timer. This timer specifies the amount of time for which a trunk will be unavailable for seizure following a release, to allow the trunk to clear before reseizing.

 500 ms

Fake Answer Supervision After Outpulsing

This option is used to complete the audio connection after outpulsing if the trunk does not provide Answer Supervision. Select "Yes" if Answer Supervision is to be provided immediately after outpulsing. Select "No" to cause the system to wait for Answer Supervision from the far-end, if any is provided.

No

Ignore Answer Supervision

Select "Yes" if the system is to ignore answer supervision from the far-end. Answer Supervision is generated by using timer and/or tone detectors. Entering "no" will indicate that Answer Supervision from the far-end is to be accepted.

No

Release Supervision
Expected

Select "Yes" if the trunk circuits are expecting Release Supervision from the far-end. Select "No" to indicate that the trunk circuits do not provide Release Supervision. The system will not allow two trunks designated as "No Release Supervision Expected" to be connected together.

Yes

Audio Inhibit Until Answer Supervision

Used to prevent a DTMF receiver, in line split mode, from being connected between the originating party and the outgoing trunk during the digit outpulsing phase of the call processing cycle. Select "Yes" and the audio path will only be connected after answer supervision has taken place. Select "No" if a DTMF receiver, in linesplit mode, is to be connected between the originating party and the outgoing trunk during digit outpulsing.

Yes

Far-End Connection

If the trunk is connected to a remote PBX, select "Main PBX" if the remote PBX routes all incoming calls through an attendant. Select "Satellite PBX" if incoming calls are not routed through an attendant. Select "Toll Office" if the trunk is connected to a toll office.

Main PBX

High Loss Option

Not applicable to this release.

No

Transmission Facility

Select "2-wire" if the trunk is 2-wire, or "4-wire" if the trunk is 4-wire.

2-wire

4 wire Carrier Condition

Select "Normal" to provide 0dB insertion loss through the PBX when the CO provides QVF equipment. When QVF equipment is provided, the associated trunk circuit meets terminal balance requirements. Select "Offset" to apply to a trunk that has no attached QVF equipment. This setting usually involves co-located PBXs. This option provides special gain with carrier systems requiring signal levels +7 dB on the Rx pair, and -16 dB on the Tx pair.

Unassigned

2 Wire Balance Network Setting

If 2-wire operation was selected, 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.

Complex

4 Wire Category

Select "Amplified" or "Not Amplified".

Blank

Perform seize tests on out-of-service trunks

This option is used to ensure that a trunk is working correctly before being returned to service. When maintenance places a circuit into an out-of-service state it generates a log indicating a state change from idle to out-of-service. A background diagnostic process is then initiated to perform a series of tests on the trunk, which include a seize test. After the trunk has passed the tests it is returned to service. Select "Yes" to do the test automatically. Select "No" and the trunk will remain in an out-of-service state until the tests are run.

Blank

Drop Digit Rcvr for Outgoing Audio Before Ans Sup

This option allows DTMF digits to be sent from a telephone to the CO without having to wait for or fake answer supervision. It also allows the system to provide exact call detail through SMDR by using the answer supervision signals provided by the CO. Select "Yes" for credit or calling card calls, calls that require pin numbers, and equal access calls. For example, if the CO recognizes a calling card call, it will send either a tone or recorded message. Once the user enters a valid card number, the call proceeds and answer supervision is returned when the called party answers.

No

Flash Timer

Enter a value between "200" and "700" milliseconds in increments of 50 milliseconds. This timer specifies the duration of the single trunk flash or each of the flashes for a double trunk flash. For a double flash, the time between flashes is hard-coded at one second.

300 ms