ISDN

ISDN (Integrated Services Digital Network) is a digital telecommunications standard that allows high speed digital connections from point to point over the ISDN network.

With ISDN, voice and data are carried by bearer channels (B channels) occupying a bandwidth of 64 kb/s (bits per second). Some North American switches limit B channels to a capacity of 56 kb/s. A data channel (D channel) handles signaling at 16 kb/s or 64 kb/s, depending on the service type.

There are two basic types of ISDN service: Basic Rate Interface (BRI) and Primary Rate Interface (PRI). BRI consists of two 64 kb/s B channels and one 16 kb/s D channel for a total of 144 kb/s. This basic service is intended to meet the needs of most individual users.

POTS (Plain Old Telephone System) cannot handle large quantities of data, it can only carry data at around 28.8kbps. ISDN can provide two data channels each operating at 64kbps (for a total throughput of 128kbps).

ISDN is an option only available for the Tieline Commander and iMix codec models. You can order a Commander or iMix with the ISDN modules already installed.

If you already own a Commander or iMix and want to upgrade it to ISDN you can order the plug and play ISDN module and install it yourself. The following items will be required for the ISDN upgrade:

• An ISDN module (2 types available “U= U.S.A” and “S/T= European”)
• Required software
• ISDN installation instructions
• Upload instructions

Please contact Tieline Technology here for further information.

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BRI (Basic Rate Interface)

BRI (Basic Rate Interface) commonly referred to as "2 B+D" BRI consists of 2 'B' channels and 1 'D' channel.

Each "B" channel operates at 64 kbps and the 'D' channel operates at 16 kbps. BRI can deliver a total bandwidth of up to 144 kbps.

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PRI (Primary Rate Interface) commonly referred to as "23 B+D

In North America and Japan PRI consists of 23 'B' channels and 1 'D' channel and provides a total bandwidth of 1.544 mbps

In Australia, Europe and other parts of the world PRI consists of 30 'B' channels and 1 'D' channel and provides a total bandwidth of 2.048 mbps

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ISDN (Integrated Services Digital Network)

A digital telecommunications standard, that allows high speed digital connections from point to point over a network.

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POTS (Plain Old Telephone System)

POTS Refers to the standard analog telephone service that is generally restricted to 3.5 kHz Bandwidth.

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U-Interface

In the U.S., the telephone company provides its BRI customers with a U interface. The U interface is a two-wire (single pair) interface from the phone switch, the same physical interface provided for POTS lines. It supports full-duplex data transfer over a single pair of wires, therefore only a single device can be connected to a U interface.

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S/T Interface

The S/T-interface is the 4-wire connection from the NT1 that connects to your ISDN device. S/T is a common standard around the world excluding North America and Canada.

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To properly configure the Tieline for ISDN there are some simple setups required. The information required depends on where you are located (due to different ISDN standards across the globe). Most of the following questions can be answered by your network provider.

North America 'U' Interface	European 'S' Interface
• What are my SPID numbers? • What is my Switch Type? • Is my ISDN line “Point to Multipoint” or “Point to Point” • What are my DN numbers?	• What is my Switch Type? • Is my ISDN line “Point to Multipoint” or “Point to Point”

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DN (Directory Number)

The Directory Number is an ISDN number assigned to each B channel of the ISDN line.

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Local Sub Address (Optional)

Two Local ISDN devices can share the same ISDN line by using a unique local sub address to identify each terminal on the BRI (Basic Rate Interface). Local sub addresses are not always required and are defined by the user in the ISDN setup.

Point–To–Point and Point-To-Multipoint

Point-to-Point is a connection between two different locations whereas Point-to-Multi-Point is a link to one or more locations.

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SPID numbers (Service Profile ID)

SPID numbers are used in North America only, and are required for addressing and handshaking to your ISDN terminal adapter

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TID (Terminal Identifier)

The TID is a two digit number for use on non-initializing terminals when required. The TID number is an extension to the SPID number during the Tieline ISDN setup.

Switch Type

ISDN switch types are protocols that different phone companies use for sending audio and data down the ISDN line.

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All Tieline codecs feature simple wizards for configuring different types of connections.

Choose a Connection Profile
First, select the profile you want to use to connect from either mono, stereo, dual mono or mono with IFB. To do this:

1. Select SOFTKEY 2 [Profile] below the LCD screen and use the MENU SELECTOR to surround the profile you want with the square brackets.
2. Press the Enter/Dial keypad button to choose your profile and press SOFTKEY 2 [Yes] to confirm.

Use the ISDN Wizard to Configure Dialing
Scroll to the ISDN connection on your codec screen, and you are ready to configure your connection.

Press SOFTKEY 3 [Wiz] below the LCD screen and then SOFTKEY 4 [OK] to proceed through the menu wizard. Selection is made by scrolling with the black rotary MENU SELECTOR and pressing SOFTKEY 4 [OK] to accept the chosen ISDN setting and to progress to the next menu item. Typical ISDN settings include programming of the:

• Network type
• Algorithm
• ISDN Line Type (Point-to-Point or Point-to-Multipoint)
• Local SubAddress
• SPIDs (Service Profile IDs)
• DNs (Directory Numbers)
• MSN (Multiple Subscriber Number)

Once all settings are programmed ISDN Configured! is displayed on the LCD screen. Press SOFTKEY 4 [OK] again to return to the main menu. It’s as simple as that and you are now ready to dial and connect!

Tieline Technology has two different ISDN Modules available. The module that you need depends on whether you have a NT-1 device connected to the line. Most North American installations do not have an NT-1.

In the U.S., the telephone company provides its BRI customers with a U interface. The U interface is a two-wire (single pair) interface from the phone switch, the same physical interface provided for POTS lines. It supports full-duplex data transfer over a single pair of wires, therefore only a single device can be connected to a U interface.

In North America, the Customer Equipment (CE) is usually connected directly to the 'U' Interface.

The situation is different Europe, UK, most of Asia, Australia, Africa and parts of the Middle East where the phone company is allowed to supply the NT-1, and thereby the customer is given an S/T interface.

The NT-1 is a relatively simple device that converts the 2-wire U interface into the 4-wire S/T interface. The S/T interface supports multiple devices (up to 7 devices can be placed on the S/T bus) because, while it is still a full-duplex interface, there is now a pair of wires for receive data, and another for transmit data.

If you have a NT1 device connected to the U interface line then you will require Tieline S/T ISDN module. If you don’t have an NT1 device installed then the Tieline U ISDN will be required. You can ring your telecommunications provider to ask if you’re not sure.

In Japan, you will need the Tieline S/T ISDN module.

North America 'U' interface		European 'S' interface
Model	Tieline Part Number	Model	Tieline Part Number
Commander Field	TLISDNUS	Commander Field	TLISDNEU
iMix	TLISDNUS	iMix	TLISDNEU

Contact Tieline here to find out how to order

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NT-1 (Network Termination 1)

The NT-1 is a relatively simple device that converts the 2-wire U interface into the 4-wire S/T interface. The S/T interface supports multiple devices (up to 7 devices can be placed on the S/T bus)

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U-Interface

In the U.S., the telephone company provides its BRI customers with a U interface. The U interface is a two-wire (single pair) interface from the phone switch, the same physical interface provided for POTS lines. It supports full-duplex data transfer over a single pair of wires, therefore only a single device can be connected to a U interface.

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S/T Interface

The S/T-interface is the 4-wire connection from the NT1 that connects to your ISDN device. S/T is a common standard around the world excluding North America and Canada.

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