BusinessPhone Communication Platform 4.0
Facilities

## Networking Based On Analogue Tielines

## Definition

“TIE LINE” denotes a permanent connection between two ASB 150 02 exchanges or between an ASB 150 02 exchange and another PBX via leased analogue lines.

## Use

### Network configurations

Tie lines are used for private network configurations consisting of two or more exchanges.

### Other applications

The printed board assemblies used for the tielines, can be used for two other applications as well.

- The BTU-E provides connection of paging equipment
- The BTU-C offers the hardware for certain types of direct in-dialling from the public network

## Operation

The operation differs depending on the network configuration of the called tie line.

### Operation in networks with open number plan (variable number length)

Dialling the route access number provides access to the exchanges of the private network. Append the desired extension number.

### Operation in networks with coordinated number plan (fixed number length)

Dial the desired extension number. The extension number is always the same, irrespective of your actual location in the network.

### Network configurations

A network shows the following characteristics:

- Number of routes
- Type of number plan
- Traffic options

#### Number of routes

Two or more exchanges may be interconnected by tie lines in one network. Each connected exchange is addressed by dialling the related route access number.

ASB 150 02 offers up to 255 routes. One tie line can be a member of several routes

#### Type of number plan

ASB 150 02 has a fully flexible one to four digit number plan (0–9999). The numbers within a network can be organised as open number plan (variable length number plan) or as coordinated number plan (fixed length number plan).

##### Open number plan (variable number length)

Each outgoing tie line route is assigned to a ROUTE ACCESS NUMBER. This number is used for the selection of the desired exchange of the private network.

After dialling the ROUTE ACCESS NUMBER you may dial the directory number of an extension or the route access number to aNother exchange.

##### Coordinated number plan (fixed number length)

All interconnected exchanges in the private network share a common numbering plan. Each exchange uses a unique first digit in its numbering plan. This first digit determines the exchange that is called.

ASB 150 02 either calls an extension within the actual exchange or forwards the call to another exchange. The extension is called if the leading digits belong to the exchange that has received the number. If the first digit belongs to aNother exchange, ASB 150 02 forwards the call to the correspondent route. The called exchange receives the dialled number – including the first digit (pre-digit) – for further analysis.

All routes and pre-digits have to be programmed for each exchange within the network, even if the routes use the same physical tie lines.

Example:

Three exchanges are connected via tie lines using a coordinated number plan. The exchange named “PBX C”, has “3” as first digit in its numbering plan.

An extension within PBX A dials the digits 3XXX. The exchange selects one of the free lines in route 3 and transmits the pre-digit 3 followed by the remaining digits to PBX B (the exchange connected to route 3).

PBX B analyses the received digits (3XXX) to forward the call to PBX C.

#### Traffic options

##### Outgoing traffic

Outgoing traffic can be automatic or manually transferred via the operator (for more informations, see Operator (380/155 34-ASB 150 02 Uen).

##### Automatic traffic

By dialling the appropriate directory number (ROUTE ACCESS NUMBER) one free individual in the route to the inter-working exchange is selected. The exchange then sends the called directory number to the inter-working exchange.

##### Manual traffic

In the event that the route has a limited number of lines or if it is a matter of a distant and expensive connection, it may be desirable to allow the operator to control traffic.

The extension then calls the operator who either transfers the line with dial tone or calls B-extension and then transfers the call.

##### Alternative routing

Alternative routing offers two alternative choices per route when the desired route is busy. ASB 150 02 adds up to ten digits before the original dialled number to access the alternative route.

Alternative routing via the public network is particularly beneficial if the public network offers the DIRECT-IN-DIALLING (DID) facility.

##### Incoming Traffic

Incoming traffic can be automatic or manually transferred via the operator.

##### Automatic traffic

When ASB 150 022 detects an incoming call, a PTS (Proceed To Send) signal is sent to the calling exchange.

The calling exchange then sends the directory number that is analysed by the called exchange.

The exchange accepts directory numbers for

- an extension
- an operator
- a PBX- (extension-) group
- an ACD-group
- a fictive number
- an outgoing line (transit traffic, see below)
- another facility related to the desired directory number

##### Adaptation of number length

The incoming (called number) can be too long or too short for matching with the internal number plan.

ASB 150 02 can add or omit pre-digits to prepare the received number for number analysis.

- Discard one to three digits before number analysis
- Add one or two digits to the received number before it is analysed

Manual traffic

In case of manual traffic the incoming line will always be routed to an answering position, for example an operator. The answering position can transfer the call to the desired extension.

Camp-on

The incoming line can be programmed for automatic camp-on to busy extensions. In this case, the caller will receive the ring control tone until the desired busy extension answers.

#### Reroute to answering position

An answering position can be defined for each incoming tie line. ASB 150 02 routes incoming calls to this answering position in the following cases:

- Called extension is busy
- Called extension does not answer
- Incomplete number received
- Calls to the desired extension are not permitted
- Called extension is blocked
- Received number is unassigned (vacant)

#### Transit traffic

An incoming tie line or exchange line can be connected to an outgoing tie line or exchange line.

Some prerequisites have to be fulfilled for transit traffic:

- The TRAFFIC GROUP MATRIX has to permit transit traffic
- The required transmission parameters and local PTT rules have to be fulfilled for transit traffic

#### Trunk line keys and abbreviated numbers

The tie line can be represented on a trunkline key of a systemtelephone.

Extensions can use abbreviated numbers for direct calls to extensions in interworking exchanges.

#### Night service

Tie lines can be night-switched to a pre-programmed directory number.

Programming of the tie lines in a separate night service group enables them to be night-switched individually.

The night service position has to be an extension number in the same exchange (except for external diversion to external targets defined as abbreviated number).

### Signalling prerequisites

#### Type of line signalling

##### Signalling provided with the BTU-C

e.g.: Loop signalling

##### Signalling provided with the BTU-E

- E&M signalling

- Swedish E&M
- Continuous E&M, A-format
- Continuous E&M, D-format
- Discontinuous E&M
- American E&M
- Paging E&M signalling according to ESPA for connection of paging equipment

- Tone signalling according CEPT L1 or SSAC 15 A

The individual signal diagrams can be adapted for several signal prerequisites. See RASC, command group 17 for more information.

#### Type of register signalling

- Decadic dialling
- DTMF (Dual Tone Multi Frequency)
- MFC and MFE

### Other applications

#### Interface for paging equipment

The BTU-E allows connection of paging equipment with signalling according to ESPA standards (2-wire speech connection including signalling for “paging in progress” and “paging equipment not present”). This allows display and tone information for the calling user.

For more information see Paging (400/155 34-ASB 150 02 Uen).

#### Direct in-dialling

The printed board assembly BTU-C offers the HW platform for certain types of Direct In-Dialling (DID) from the public network.

More information see Direct In-Dialling (162/155 34-ASB 150 02 Uen).

## Capacity

### Number of tie lines

The maximum number of trunk lines and tie lines in ASB 150 02 is 60.

### Number of routes

One ASB 150 02 exchange supports up to 255 routes.

## Limitations

There are no limitations for analogue tie lines, compared with analogue trunk lines.

The following features are Not supported by analogue tie lines (via BTU-E and BTU-C).

- Diversion, follow-me and re-route to extensions in interworking exchanges is not supported. (External diversion to parties defined in abbreviated numbers is possible.)
- The A-number and the B-number are not transmitted via analogue tie lines
- The operator receives no other information on the display than called or calling line number when forwarding calls from interworking exchanges
- Sending messages to extensions in interworking exchanges is not possible
- An extension calling from another exchange can receive VOICE INFORMATION only
- Members of groups, within the PBX, must belong to the same exchange. Examples of such groups are:

- PBX-groups
- ACD-groups
- Group pick up groups

- Intercom cannot be used for connections between extensions in two different exchanges
- Supervision of directory numbers belonging to other exchanges is not possible
- Call-back from extensions situated in another exchange is not possible
- However, call-back on individual tie lines or tie-line routes is possible
- Call metering information is not received from analogue tie lines
- Intrusion to extensions in other exchanges is not possible
- The call status (free, free on line 2, busy…) is not displayed on the telephone when calling an extension in another exchange (see exception for MFC and MFE signalling)

### Exception for MFC or MFE signalling

MFC and MFE signalling supports call-status display information for the following cases:

- free
- busy
- congestion
- blocked
- number unavailable

## Programming

Each tie line can be programmed for adaptation to another PBX. Adaptation of line signalling and system times requires familiarity with ASB 150 and the relevant signal diagram.

The descriptions of commands provided below are concise and provide a handling program for tie line programming.

### Order for programming external line data

The recommended order for programming external line (trunk) data is provided below.

Program one route at a time. Program one line in the route and copy its data to other lines in the route. Then repeat the procedure for the other routes.

### Route selection

5401 |  | Create a route

In ASB 150 a route is a list of trunk lines. When calling the route's directory number, a free trunk will be seized in accordance with a defined allocation principle.

This command will create a new route with the stated directory number. The route may be given a random directory number, if there is one that does Not conflict with existing directory numbers. (See command group 56). ASB 150 allows a maximum of 250 routes.

3201 |  | Trunk route members

This command states which trunks are to belong to a route as well as the position of the trunk within the route.

A trunk is removed from a route by erasing the Valid data of the relevant directory number.

Before this command can be executed, the command for creating route access codes (5401) must have been executed.

See also Route Selection (444/155 34‑ASB 150 02 Uen).

3301 |  | Random Selection

This command defines the selection principle to be used for a route.

Valid data: Yes/No

Yes |  | sequential selection with alternating start point. Search for a free trunk starts with the position number following that of the latest seized trunk.

No |  | sequential selection from first trunk.

- Search for a free trunk always starts at the first trunk in the route.

### Number series

3303 |  | Predigits

This command is used to define predigits, if any, for a normal route. The predigits are transmitted before the dialled external number.

Predigits = 1-10

The command is used to differentiate between variable and fixed numbering schemes. Normally, predigits need not be stated for variable numbering schemes. Predigits are to be stated for fixed number series.

3304 |  | First alternative route

When all trunks between two exchanges are busy, the call can be sent via another exchange. An alternative route shall be defined for the call to be rerouted. Two different alternative routes can be defined.

The first alternative route is defined with command 3304. The second alternative route is defined with command 3306.

3305 |  | Predigits for first alternative route

Command 3305 is used to define predigits (if any) for the first alternative route. Command 3307 is used to define predigits (if any) for the second alternative route.

The predigits are transmitted before the dialled external number.

Predigits = 1-10

3306 |  | Second alternative route

See command 3304

3307 |  | Predigits for second alternative route

See command 3305

1015 |  | Pre-digits for number analysis

This command is used to assign routes and their members a number which may be used for number analysis. This parameter will be used primarily by TCD and LCR.

The number given should contain 1-4 digits.

See also Trunk Call Discrimination (TCD) (487/155 34-ASB 150 02 Uen).

### Categorisation

1001 |  | Facility COS

1002 |  | Traffic group

1003 |  | TCD-day COS

1004 |  | TCD-night COS

1005 |  | Common abbreviated number COS

1006 |  | Call back allowed ?

1007 |  | Break-in allowed ?

1008 |  | Break-in allowed ?

These commands state which facility the trunk belongs to. The facility category controls the number of facilities to which the trunk has access to.

Trunks (and extensions) can be divided into 16 different facility categories (Valid data 0-15).

For each category and each facility it is possible to control whether or not the access to the facility shall be permitted.

1019 |  | Night-switching group

The command states the night-switching group to which the trunk belongs.

Valid data: 1-8

Night-switching of the PBX means that incoming calls to each individual trunk are routed to a common answering position. Night-switching of a trunk group means that incoming calls on trunks included in the group will be routed to a common answering position.

### Outgoing traffic

1201 |  | Line signal scheme

The command is used to select the line signal table. The selection is based on the type of the interworking exchange connected.

1013 |  | Dial tone to extension ?

The command is used to determine whether or not a dial tone shall be sent to callers (A-party) in case of outgoing calls.

1014 |  | Result tones to parent exchange ?

The command is used to determine whether a result tone shall be sent to the parent exchange. This applies both to incoming and outgoing calls.

1302 |  | Outgoing digit transmission

The command states how the digits are sent by the interworking exchange.

The initial valid data depends on the type of the BTU.

Valid data: 0-5

0 |  | = Decadic impulsing

1 |  | = DTMF

2 |  | = MFC

3 |  | = No sending of digits

4 |  | = MFE1 (2/5)

5 |  | = MFE2 (2/6)

The following default valid datas are trunk board dependent:

Valid data:

BTU-A |  | = 0

BTU-C |  | = 0

BTU-E |  | = 0

BTU-D |  | = 2

1303 |  | Impulse Type

The command is used at impulsing to determine the dialed digit's relation to the number of pulses.

The number of impulses 1 2 3 4 5 6 7 8 9 10

Valid data: 0-3

0 |  | = digit 1 2 3 4 5 6 7 8 9 0

1 |  | = digit 0 1 2 3 4 5 6 7 8 9

2 |  | = digit 9 8 7 6 5 4 3 2 1 0

3 |  | = digit 0 9 8 7 6 5 4 3 2 1

1304 |  | Impulse frequency

The command states which impulse frequency is to be used at decadic impulsing.

Valid data : Yes/No

Yes |  | = 10Hz

No |  | = 16 Hz

1305 |  | Impulse ratio

The command is used to determine which make/break relation (stated in percent) that is to be used at decadic impulsing.

Valid data: Yes/No

Yes |  | = 40/60

No |  | = 33/67

1306 |  | Inter digit pause

The command is used to determine the pause between the digits valid for decadic impulsing.

Valid data: 00-15

00 |  | = 300ms
08 |  | = 700ms
01 |  | = 350ms
09 |  | = 750ms
02 |  | = 400ms
10 |  | = 800ms
03 |  | = 450ms
11 |  | = 850ms
04 |  | = 500ms
12 |  | = 900ms
05 |  | = 550ms
13 |  | = 950ms
06 |  | = 600ms
14 |  | = 1000ms
07 |  | = 650ms
15 |  | = 1050ms

1307 |  | PTS-signal from parent exchange ?

The command is used to state whether the exchange shall wait for a proceed-to-send signal (PTS signal) from the parent exchange. See command 1404 for wrong proceed-to-send signal if the exchange does not send any signal. (Command 1308 states whether the proceed-to-send signal is the dial tone. See also command 1013, which states whether dial tone shall be sent to the extension.)

1308 |  | PTS-signal from parent exchange = dial tone

The command states whether the proceed-to-send signal from the parent exchange is the dial tone. (Command 1307 states whether a proceed-to-send signal is sent by the parent exchange. See also command 1013 which states whether a dial tone shall be sent to the extension.)

1404 |  | Wait time before start to send digits when no PTS

The command is used to determine the shortest time required by the parent exchange to receive digits for outgoing calls from ASB 150 02. The function is used when the parent exchange does not send any proceed-to-send signal as acknowledgement.

Valid data: 0-255 seconds

0 |  | = No waiting time before digit transmission

1710 |  | Seizure acknowledge

The command is used to state whether the line signal “seizure acknowledge” shall be received (exists) at an outgoing call.

Note

Ascertain that the signal is included in the selected line signal scheme.

1717 |  | Answer signal ?

The command is used to state whether the line signal “answer” shall be received (exists) at outgoing calls.

Note

Ascertain that the signal is included in the selected line signal scheme.

### Incoming traffic

1103 |  | Rerouting position at day

1104 |  | Rerouting position at night

See also Answer Position(s) For Trunks (112/155 34-ASB 150 02 Uen).

1023 |  | Trunk line type

The command is used to state to which type of trunk the BTU is connected.

Valid data: 0-2

0 |  | = Trunk to a public exchange (PE)

1 |  | = Trunk from a public exchange with direct indialing (INDIALING)

2 |  | = Trunk to a private exchange, tie line (TIE LINE)

1309 |  | PTS-signal from parent exchange = dial tone

The command states whether the PTS-signal for incoming traffic consists of a dial tone.

1311 |  | Number of digits before EOS-signal

The command is used to determine the number of received digits for automatic incoming traffic before sending the EOS-signal to the superior exchange, e.g. a predetermined number of digits is always received before the EOS-signal is sent.

Valid data: 1-4 digits.

1706 |  | Seizure acknowledge

The command is used to state whether the signal “seizure acknowledge” shall be sent as reply to “seizure” at an incoming call.

Valid data: Yes or No

Note

Ascertain whether the signal is included in the selected line signal scheme.

1707 |  | PTS-signal ?

The command is used to state whether the “Proceed-To-Send” signal (PTS) shall be sent as line signal for an incoming call.

Valid data: Yes or No

Note

Ascertain whether the signal is included in the selected line signal scheme.

If “Proceed-To-Send” signal is to be sent as dial tone it is defined by command 1309.

1709 |  | Answer signal ?

The command is used to state whether the line signal “answer” shall be sent at an incoming call when the call is answered in the exchange.

Valid data: Yes or No

Note

Ascertain whether the signal is included in the selected line signal scheme.

1411 |  | Time supervision for first digit at automatic incoming traffic

The command is used to state the supervision time for incoming calls between seizure and first digit. The parameter shall only be used for direct in-dialing lines and automatic incoming tie lines.

Valid data : 0-255 seconds.

0 |  | means that no time supervision takes place.

1412 |  | Time supervision between digits at automatic incoming traffic

The command is used to state the supervision time for incoming calls between digits. The parameter shall only be used for lines of type direct indialling and automatic incoming tie lines.

Valid data: 0-255 seconds.

If the parameter is set to zero there will be No time supervision.

1413 |  | Time supervision of answer at automatic incoming traffic

The command is used to state the supervision time for incoming calls between End Of Selection and answer before rerouting to an alternative answering position. The parameter shall only be used for lines of type direct in-dialing and automatic incoming tie lines.

Valid data: 0-255 seconds.

If the parameter is set to zero there will be no rerouting.

1802 |  | Pre-digits at automatic incoming traffic

The command is used to state the digits that shall be inserted before the incoming number before it is analyzed.

Valid data: 1-2 digits

1803 |  | Irrelevant digits at automatic incoming traffic

The command is used to state how many initial digits in the incoming number shall be omitted before the number is analyzed.

Valid data: 0-3

### Name String

6601 |  | Administrative data for extension

This command defines a name string for extensions and trunks.

Enter the name of the extension or trunk, a maximum of 35 characters

6501 |  | Directory name

This command defines a name string for a directory number, e.g. for a route.

Enter the relevant directory number.

Enter the relevant text, maximum 35 characters.

### Trunk answering position

The command group 11 determines the destination of incoming and rerouted calls.

Incoming calls are routed to the specified answering position. Specify the answering position by its directory number. The command “4001 alternative answering position for general operator” is not active when the directory number for an individual answering position is defined.

1101-1104 |  | Programming of answering positions

On system start all trunks are directed to directory number 200.

Four different answering positions can be programmed for each trunk:

1101 |  | Individual answering position at day

1102 |  | Individual answering position at night

1103 |  | Reroute position at day

1104 |  | Reroute position at night

A call is directed to an alternative answering position when the normal answering position does not answer within a predetermined time

Enter the directory number of the relevant answering position.

Default data = 200

Step to commands 1102-1104 and repeat above procedure.

Note

Make sure that the trunk is presented on a function key, if you want to delete directory numbers for above commands.

### Adjust Filter coefficient for BTU-E

1609 |  | Filter coefficient

This command is used to state the filter coefficient in the analogue interface on the line board.

The impedance is stated as:

Rs (ohm) + Rp (ohm) // Cp (nF).

Valid data: 98-255

## Equipment

### BTU-E-E&M Tie Lines

The BTU-E provides four E&M tie lines capable of handling various signalling schemes:

- Swedish E&M
- Continous E&M signalling, A-format or D-format, 2-wire or 4-wire speech connection
- Discontinuous E&M signalling, 2-wire or 4-wire speech connection
- E&M with blocking on separate E and M wires (for 2-wire and 4-wire speech connection)
- American E&M
- Tone signalling according to CEPT L1 or SSAC 15 A
  (4-wires used for speech and signalling)
- Application for paging equipment according to ESPA standards (2-wire speech including signalling for “paging in progress” and “paging equipment not present”)

### Different types of BTU-Es

#### BTU-E

- 2- or 4-wire speech-connection has to be adjusted via jumpers on the board.
- Set the Line signal schemes via command 1201.

- The following Line signals chemes are not supported:

- 44 CEPTL 1
- 45 CAILHO-discontinous
- 46 SSAC 15-A

#### BTU-E/1

- Set the line signal-scheme via command 1201.

- The following line signal-schemes are not supported:

- 44 CEPTL 1
- 46 SSAC 15-A

- 2- or 4-wire speech-connection has to be adjusted via command 1609.

- Only the following setting supports 4‑wire speech connection: “116”
- All the others support 2-wire speech connection.

Note

If you program command 1609 for 4-wire speech connection, you HAVE TO set the line signal-scheme once again!

#### BTU-E/2

- Set the line signal-scheme via command 1201.

- All line signal-schemes are supported.

- 2- or 4-wire speech-connection has to be adjusted via command 1609.

- Only the following setting supports 4‑wire speech connection: “116”
- All the other support 2-wire speech connection.

Note

If you program command 1609 for 4-wire speech connection, you HAVE TO set the line signal-scheme once again!

#### BTU-C - DC-Loop Tie Lines

The BTU-C is available in two versions.

The Version /2 of the BTU-C provides 4 DC-loop tie lines.

In Australia Version /1 can only be used as a trunk board and cannot be used as a tie-line board.

#### Registers for DTMF, MFC or MFE signalling.

To use the register function as a common system resource for all trunklines, one of the following boards has to be avaialble in the system

#### REG , BTU-D, VMU-HD or MFU

The number of available registers depends on the load of the digital signal processors (DSP), see board description in the document System Description ASB 150 02 (1551-ASB 150 02 Uen).

Revision: G © Ericsson Enterprise 2003