ISDN

---

What is it

What is it

The Integrated Services Digital Network (ISDN) is a very important evolution of the public telephone network in terms of improvement, enhancement and extension of the services currently offered by the existing dedicated networks. In fact, ISDN allows integrated transmission of voice, data and images on the same subscriber lines, eliminating the need for additional access lines.

Main Characteristics

ISDN's main characteristics are: high-quality and reliable transmission (digital connection from user to user), high bit-rate transmission (B channels at 64 kbit/s) and high flexibility (support of a combination of access facilities and of a wide range of services and applications).

Main Applications

ISDN's main applications are: file transfer, videocommunication, LANs interconnection, leased channels back-up and access to remote database.

Main Fields

The ISDN allows transmission of a wide variety of information supporting applications in all fields. In particular:

• trade (distributed management of stores, real estate purchase and sale)
• industry (remote maintenance, after-sale assistance, teleworking)
• medical fields (teleconsulting, access to remote biomedical image databases)
• publishing and communication (access to news and remote image databases, multimedia news diffusion)
• tourism (distribution of electronic catalogues, reservation services)
• education (telelearning)
• finance (remote signature validation, telesurveillance)

Access Types

Two standard network access are available:

• Basic access, that consists of two channels at 64 kbit/s (type "B"), used for circuit and packet mode services, and one channel at 16 kbit/s (type "D") used for signalling information; it connects up to ten user terminals;
• Primary acces, that consists of thirty channels at 64 kbit/s (type "B") used for circuit and packet mode services, and one channel at 64 kbit/s (type "D") used for signalling information; it connects ISDN PABXs and LANs.

The Italian Network

In service since June 1992, the Italian ISDN network actually connects 180 cities and allows international connections with Belgium, Denmark, France, Germany, U.K., Norway, Netherland, Sweden, U.S.A., Japan, Australia and Singapore. Italian ISDN is also interconnected, for national and international calls, with the normal telephone network (PSTN), with ITAPAC, the Italian packet switched public data network (PSPDN), and with RFD (Rete Fonia Dati), the domestic public circuit-switched voice and data network (CSPDN).

Telecom will spread ISDN service over the whole nation by the end of 1995.

ISDN in LINEA UT

LINEA UT can support ISDN services by adding to a subscriber module the appropriate user interface: one card (ILCDU) for eight basic access, two cards (UL-US) for one primary access.

ISDN Services available in the LINEA UT

• The following supplementary services are made available by ISDN to customers:
• CLIP (Calling Line Identification Presentation)
• CLIR (Calling Line Identification Restriction)
• COLP (Connected Line Identification Presentation)
• COLR (Connected Line Identification Restriction)
• DDI (Direct Dialling In)
• MSN (Multiple Subscriber Number)
• TP (Terminal Portability)
• CW (Call Waiting)
• MCID (Malicious Call Identification)
• CUG (Closed User Group)
• UUS1 (User to User Signalling Part 1)
• SUB (Subadressing)
• AOC-D (Advice of Charge - During)
• AOC-E (Advice of Charge - End)
• CCBS (Call Completion on Busy Subscriber)
• CFB (Call Forwarding Busy)

ISDN and Italtel

Italtel, one of the main European telecommunication manufacturers, began ISDN implementation in Italy in 1984 when an ISDN field trial, defined by Italtel in collaboration with CSELT (Centro Studi e Laboratori Telecomunicazioni) and SIP, was presented to the international scientific community in Florence during the International Switching Symposium. Italtel's research and development has matured more than ten years since then.Telphones, PABX, terminal adaptors, boards for personal computer, videoconference systems, multimedial information points: a complete offering both for small and big companies, for professional offices, and for all business that look at ISDN as a working tool assuring competitive advantages. System support, solutions worked out with customers, economic and financial analysis, and distributed service and support characterize Italtel's global ISDN offering.

Italtel Societa' Italiana Telecomunicazioni Spa

Claudio Chiarenza, BUCT BPM
Comments to author:Claudio.Chiarenza@settimo.italtel.it

Contact for Information: Claudio Chiarenza - BUCT BPM

All contents copyright (C) 1995.Italtel S.p.a. All rights reserved.
Revised: August 30, 1995