Computer Network Tutorial

Introduction of Computer Network Types of Computer Network Network Topology Computer Networking Architecture Transmission Modes (Data Flow) Basic Networking Devices Integrate Services Digital Network (ISDN)


OSI Model TCP/IP Model

Physical Layer

Digital Transmission Analog Transmission Transmission Media Switching

Data Link Layer

Error detection and Error correction Data Link Control Multiple Access Aloha

Network Layer

Network Layer - Logical Address Address Mapping Unicast Routing Protocol

Transport Layer

Process to Process Delivery User Datagram Protocol Transmission Control Protocol Stream Control Transmission Protocol Session Layer and Presentation Layer

Application Layer

Domain Name System Application Protocol E-mail Cryptography


Classes of Routing Protocols Classification of Routing Algorithms Controlled Access Protocols in Computer Networks Differences between IPv4 and IPv6 Fixed and Flooding Routing Algorithms Advantages and Disadvantages of Fibre Optics Cable APIPA Difference between Active and Passive FTP Fiber Optics and its Types Method of Joining and Fusion of Fiber Optic Cable Define Framing in Computer Network Disadvantages of Computer Network Mesh Topology Diagram in Computer Network Ring Topology in Computer Network Star Topology in Computer Networks 4G Mobile Communication Technology Advantages and Disadvantages of LAN Advantages and Disadvantages of MAN Advantages and Disadvantages of WAN Application Layer in OSI Model Cyclic Redundancy Check Example Data link layer in OSI model Difference between Transport and Network Layer Hamming Code Example Network Layer in OSI Model Session Layer in OSI Model Transport Layer in OSI Model Two Port Network in Computer Networks Uses of Computer Networks What is Computer Network What is Framing in a Computer Network Advantages and Disadvantages of Bus Topology Difference between Star Topology and Bus Topology Subnetting in Computer Network Subnetting Questions and Answers What is Bus Topology What is Network Topology and Types in Computer Networks Access Control in Networking Basic Characteristics of Computer Network Benefits of SOCKS5 Proxy in Computer Networks Computer Network viva Questions Difference between BOOTP and RARP Difference Between Network Topologies and Network Protocols Difference between NFC and RFID Difference Between Point-to-Point Link and star Topology Network Differences Between MSS and MTU Differences Between Trunk Port and Access Port Different Modes of Communication in Computer Networks MIME Protocol in Computer Networks Modes of Communication in Computer Networks Network Attack in Computer Network Port Address in Networking Simplest Protocol in Computer Network Sliding Window Protocol in Computer Network Stop And Wait Protocol in Computer Networks TCP 3-Way Handshake Process in Computer Networks What is a Proxy Server What is APPN What is ICMP Protocol What is Point-to-Point Protocol What is Port Address in Networking What is the HDLC Protocol What is VRRP Protocol Difference Between Analog and Digital Signals Difference Between Hub and Repeater Difference between Repeater and Switch Difference Between Transparent Bridge and Source Routing Bridge Source Routing Bridge in Computer Networks Transparent Bridge in Computer Networks Transport Protocol in Computer Networks Types of CSMA in Computer Networks What is Wired and Wireless Networking Network Security in Computer Network Disadvantages of Extranet Difference Between TELNET and FTP Define Protocol in Computer Networks Guided Transmission Media in Computer Network What is a Gateway in a Computer Network IGMP in Computer Networks LAN Protocols in Computer Networks MAN Meaning in Computer Modulation Techniques in Computer Networks Switching in DCN TCP/IP Applications What is IGMP? What is Modem in Networking What is Non-Persistent CSMA Difference between Cell Splitting and Cell Sectoring Forouzen Computer Network

Integrated Services Digital Network (ISDN)

Integrated Services Digital Network (ISDN): ISDN means Integrated Services Digital Network. ISDN was developed by ITU-T in the 1980s. These are digital telephony and data transport services offered by regional telephone operators. ISDN includes the physical, data link, and network layers of the OSI model.

The main objective of ISDN is to provide fully integrated digital services to the users. ISDN is actually a set of communication protocols that were offered by telephone corporations. These include the digital services of the telephone network. ISDN allows the data to be sent over existing telephone cables, and these data are video, audio, text, and file in the form. The main goal of the ISDN is provided to the end-to-end connectivity in the worldwide from of the WANs. Another goal of ISDN is also to provide a combination of voice and non-voice services.

Narrowband ISDN is the first generation of the ISDN. Narrowband ISDN is based on the basic unit of the switching, and this unit is 64 kbps. The frame relay is the primary device of the Narrowband ISDN. Broadband ISDN (B-ISDN) is a second generation of the ISDN. The second generation of ISDN supports very high data rates, usually hundreds of Mbps. Asynchronous Transfer Mode (ATM) is the main technical contribution of the B-ISDN, which is also known as the cell relay.

The Architecture of ISDN shown in below:

Integrated Services Digital Network (ISDN)

Advantages of ISDN

1. ISDN can operate the video, voice, text, and data simultaneously.

2. The call setup of the ISDN is faster than the analog modem.

3. It provides higher data rates.

4. ISDN provides fully digital services, so the probability of error is very low.

ISDN provides three types of digital services:

  1. Bearer Services: Bearer services offer the path for transfer data between the users without the network manipulating the content of that data. Bearer services are related to the Physical, Data-link, and Network layer of the OSI model. Bearer services can be used with the help of the packet switched, cell switched, circuit switched, and frame switched networks.
  2. Tele Services: Tele services depend on the facilities of the bearer services. It is designed for the requirements of complex users. Tele Services provides various types of services such as Telephony, telex, telefax, and video conferencing.
  3. Supplementary Service: Supplementary services provide extra features to Bearer services and Tele services. Examples of the Supplementary services are call waiting, message handling, reverse charging, etc.

There are two types of interfaces associated with the ISDN:

  1. BRI (Basic Rate Interface)
  2. PRI (Primary Rate Interface)

BRI: BRI stands for Basic Rate Interface. In the ISDN, BRI provides two B-channels and one D-channel to initiate connections, i.e. (2B + D). The B-channels work at the 64 Kbps for each channel, while the D-channel works at the 16 Kbps.

PRI: PRI stands for Primary Rate Interface. In the ISDN, PRI provides 23 B-channels and 1 D-channel. The PRI offers an aggregate data rate of 1.544 Mbps. The PRI services are very expensive, and it is used to connect many computers and devices on a large scale. 

The ISDN channels table shown below with each transmission data rates:

ChannelsTransmission Data Rates
AA-channel operates the 4 KHz analog telephone data rate.
BB-channel operates the 64 Kbps digital PCM channel data rate for voice and data.
CC-channel operates the 8 or 16 Kbps digital channel data rate.
DD-channel operates the 16 Kbps digital channel for out of the band signaling.
EE-channel operates the 64 Kbps digital channel data rate for internet ISDN signaling.
HH-channel operates the 384, 1536, or 1920 Kbps digital channel data rate.