Integrated Services Digital Integrated Services Digital NetworkNetwork

By By Preeti PatelPreeti Patel

LectureLectureSchool of Library And Information ScienceSchool of Library And Information Science

DAVV, Indore DAVV, Indore Email: Email: preetipatel2407@yahoo.co.inpreetipatel2407@yahoo.co.in

Integrated Services Digital Integrated Services Digital NetworkNetwork

Introduction to ISDNIntroduction to ISDNHistory of ISDNHistory of ISDNChannels of ISDNChannels of ISDNFeatures of ISDNFeatures of ISDNUse of ISDNUse of ISDN

Introduction to ISDNIntroduction to ISDN

Integrated Services Digital NetworkIntegrated Services Digital NetworkIt is a telephonic system. Which provide digital It is a telephonic system. Which provide digital

(not analog) telephone and data services. As it (not analog) telephone and data services. As it supports digital services (include digital voice), supports digital services (include digital voice), the ISDN telephone users enjoy Voicethe ISDN telephone users enjoy Voice--free, CDfree, CD--Quality, Sound. Moreover with the ISDN no Quality, Sound. Moreover with the ISDN no modem is necessary because it supports digital modem is necessary because it supports digital transmission of all types of data (including transmission of all types of data (including voice). This also results in very short call setup voice). This also results in very short call setup time between two ISDN subscribers. time between two ISDN subscribers.

Integrated Services Digital NetworkIntegrated Services Digital Network

ISDN is a circuit ISDN is a circuit ––swiched telephone network swiched telephone network system, Which designed to allow digital system, Which designed to allow digital transmission of voice and data over ordinary transmission of voice and data over ordinary telephone copper wires, resulting in better voice telephone copper wires, resulting in better voice quality than an analog phone. ISDN channels quality than an analog phone. ISDN channels may use bonding to achieve a greater data rate, may use bonding to achieve a greater data rate, typically 3 or 4 BRIs (6 to 8 64 kbit/s channels) typically 3 or 4 BRIs (6 to 8 64 kbit/s channels) are bonded. ISDN is designed to provide access are bonded. ISDN is designed to provide access to voice and data services simultaneously to voice and data services simultaneously

ISDN elementsISDN elements

Integrated ServicesIntegrated Services refers to ISDN's refers to ISDN's ability to deliver at minimum two ability to deliver at minimum two simultaneous connections, in any simultaneous connections, in any combination of data, voice, video, and fax, combination of data, voice, video, and fax, over a single line. Multiple devices can be over a single line. Multiple devices can be attached to the line, and used as needed attached to the line, and used as needed

Digital refersDigital refers to its purely digital to its purely digital transmissionUse of an analog telephone transmissionUse of an analog telephone modem for Internet access requires that modem for Internet access requires that the Internet service providers’s (ISP) the Internet service providers’s (ISP) modem converts the digital content to modem converts the digital content to analog signals before sending it and the analog signals before sending it and the user's modem then converts those signals user's modem then converts those signals back to digital when receiving. When back to digital when receiving. When connecting with ISDN there is no digital to connecting with ISDN there is no digital to analog conversion. analog conversion.

Network refersNetwork refers to the fact that ISDN is not to the fact that ISDN is not simply a pointsimply a point--toto--point solution like a point solution like a

Leased line. ISDN networks extend from Leased line. ISDN networks extend from the local telephone exchange to the the local telephone exchange to the remote user and includes all of the remote user and includes all of the telecommunications and switching telecommunications and switching equipment in between. equipment in between.

History of ISDNHistory of ISDN

•• Developed by CCITT (Comate Consultative Developed by CCITT (Comate Consultative International Telephonique Telegraphs) to International Telephonique Telegraphs) to limitation of POTS (Plane old Telephone limitation of POTS (Plane old Telephone system). system).

•• Original document was I.120 version in 1984.Original document was I.120 version in 1984.•• Early 1990s produced NIEarly 1990s produced NI--1version.1version.•• More recently NIMore recently NI--2 also manufactures worked 2 also manufactures worked

with phone companies to simplify ordering.with phone companies to simplify ordering.

Channels of ISDNChannels of ISDN

1.1. B ChannelB Channel2.2. D ChannelD Channel3.3. H ChannelH Channel

B ChannelB Channel

The B (Barrier) channel carriesThe B (Barrier) channel carriesvoice, data, video etc. This Channel voice, data, video etc. This Channel functions at a constant 64 kbps. This functions at a constant 64 kbps. This channel can be used for packet and circuit channel can be used for packet and circuit switching applications.switching applications.

D channelD channel

In ISDN the D (Denial) channel is used to In ISDN the D (Denial) channel is used to convey user signaling massages. This convey user signaling massages. This type channel used out of band signaling . type channel used out of band signaling . This means that network related signals This means that network related signals are carried on a separate channel than are carried on a separate channel than used data.used data.

H ChannelsH Channels

H channels have a considerably higher H channels have a considerably higher transfer rate than B channels. These transfer rate than B channels. These channels effectively meet the needs of real channels effectively meet the needs of real time video conferencing, digital quality time video conferencing, digital quality audio and other services requiring a much audio and other services requiring a much higher bandwidth. H channel sustains higher bandwidth. H channel sustains rates of approximately 1920 mbps.rates of approximately 1920 mbps.

Features of ISDNFeatures of ISDN

In ISDN very short time to connect a calling In ISDN very short time to connect a calling between two users of ISDN.between two users of ISDN.

Signals, messages or data send in the digital Signals, messages or data send in the digital form on the ISDN line. In which provide high form on the ISDN line. In which provide high quality database services.quality database services.

The user of ISDN also communicate The user of ISDN also communicate information with all the general telephone information with all the general telephone user.user.

Use of ISDNUse of ISDN

Electronic library Inter connection.Electronic library Inter connection.Electronic resources accessing.Electronic resources accessing.Images, sound and video retrieval.Images, sound and video retrieval.Video conferencing.Video conferencing.Call center.Call center.Internet Access.Internet Access.