About Narrowband ISDN?

1. Narrow Band ISDN
Submitted by,
M . Kavitha

2. Introduction:
* ISDN – Integrated Service Digital Network Narrowband
ISDN. The ISDN and B – ISDN had a dramatic impact on the
planning and deployment of intelligent digital network providing
integrated service for voice, data and video.
* The work on ISDN and B – ISDN standards had led to
the development of two major new networking technologies, frame
relay and asynchronous transfer mode (ATM).
* ATM have become the essential in gredients in
developing high speed networks for local, metropolitan and wide
area applications.

3. Narrow Band ISDN:
* The ISDN is intended to be a worldwide
telecommunication network to replace existing public
telecommunication network and deliver a wide variety of service.
* ISDN is defined by the standardization of user interface
and implemented as a set of digital switches and path supporting a
broad range of traffic types and providing value added processing
services.
* The narrow band ISDN is based on the use of 64 kbps
channel as the basic unit of switching and has a circuit switching
orientation. The major technical contribution of the narrowband
ISDN effort has been frame relay.

4. Narrow band B – ISDN:
* The B – ISDN support very high data rates (100s
of Mbps) and has packets switching orientation.
* N – ISDN (Narrow band Integrated switch Digital
Network ) was an attempt to replace the analog telephone system
with a digital one.
* It generally uses 64 kbps channel as the basic unit
of switching. It has a circuit switching orientation. It major
contribution was frame relay.
* It describe telecommunication that carries voice
information in a narrow band of frequencies.

5. ISDN and B-ISDN
* Integrated Services Digital Network (Narrowband
ISDN)
* Broadband ISDN
ISDN is a new WAN technology:
* Beyond circuit-switching and packet switching. It
provides a set of channels at a single interface
* B channel: 64kbps, a principal channel to replace
circuit switching, packet switching, and leased lines.
* D channel: used for control signaling (call setup) and
may also carry some data. For residential users two B channels
and one D channel are adequate

6. B-ISDN:
* A second-generation specification for ISDN.
* It provides for high data rates. The enabling technique
is ATM.
ISDN:
* Merger of computer and communication technologies.
* Demands for efficient and timely processing of
information (single interface).
* Demands for high data rates.
* The pipe has a fixed capacity, but the traffic on the pipe
may be variable.
* Complex control signals are required to manage a
dynamic mix of different traffic,
Example: Circuit switching and packet switching.

8. Architecture
@ ISDN architecture consists of a new physical interface for
DTE-DCE connection, a digital subscriber loop and central office
equipment
* The new interface should be usable for
telephone, computer and video tex terminals
* Subscriber loop consists of twisted-pair links
carrying 4-kHz analog signals
* The central office should provide circuit switched
network, dedicated lines, packet switched networks and other
Transaction services.

10. B-ISDN protocols:
@ ATM network is used as user network interface:
* B-ISDN is a packet-based network
* Circuit-switching is done over packet-switching
* A new era for ISDN, which began from circuit-switching
telephone network
@ Protocol reference model:
* User plane: for user information transfer
* Control plane: call control and connection management
* Management plane: management functions,
coordination between planes, and layer management

11. ISDN protocol architecture:
@ Layer 1: I.430 and I.431:
* Physical interface for both basic and primary access
* B and D channels are multiplexed over the same
physical interface.
@ Layer 2: LAPD and LAPB:
* For D channel a new data link layer protocol
Link Access Protocol, D channel is used
* For B channel Link Access Protocol Balanced is used
* All transmission on the D channel is in the form of
LAPD frames.
* Three applications are supported: control signaling,
packet-switching, and telemetry.
@ Layer 3:
* Control signaling: Q.931
* Packet-switching: X.25
* Telemetry

12. Conclusion:
ISDN and B-ISDN, attempts to use a
single network to serve all tele/data communications customers
Enabling techniques,
* ATM
* Frame relay
@ Principles of ISDN.
@ A standard and uniform interface is provided to users.
@ Objectives of ISDN.
@ ISDN Channels:
* B channel
* D channel
* H channel
@ ISDN protocol architecture.
@ ISDN connections.
@ B-ISDN protocol reference model.

13. Thank You