CNDS ISDN Presentation Group Members: 1.Kok Wai Hien KL Oon Thiam TeckKL Lim Cheah YiingKL Woon Yen LinKL Tan Pei VoonKL Monica ChoyKL Leong Pui YeeKL Lecturer: Miss Ponnu Devi

Objective  To integrate the service network in WAN.  Discuss Future Application and Services that will benefits from broadband.  Discuss Channels of ISDN.

Introduction  What is ISDN?  Stands for Integrated Services Digital Network  Is a system of digital phone connections.  Allows data to be transmitted simultaneously across the world -- end-to-end digital connectivity.

 The combining of voice and data services over the same wires.  Provides a huge improvement in access speed.  It's equally available to home and business customers.  Supports both circuit switching and packet switching.

History  Conventional phone system use analogue  Great inefficiency  Prone to breakdown and noise  Did not lend itself well to long-distance connections  In the 1960’s, the telephone system began converting its internal connections to a packet- based, digital switching system.

 Today, most voice switching in the world is digital.  Recently, ISDN service has been displaced by broadband internet service.  These services are :  faster  less expensive  and easier to set up and maintain than ISDN.

 Benefits of ISDN :  To the user  cost savings and flexibility.  single access line to all services.  To network providers  support larger potential market for services.  drive down equipment costs.

 To manufacturers  larger potential market, economies of scales.  standards decrease risk of obsolescence.  To enhanced service providers  simplified user access.

Conceptual View

ISDN Architecture:

 All modern switches are able to switch ISDN calls, using ISDN line cards and ISDN feature software.  Digital signal takes place between the customer's terminal and the central office.  Terminal Equipment (TE) -- connected computers, fax machines, LANs, or telephone sets. TE1 – connect directly through 4 wired twisted pair digital link TE1 – connect directly through 4 wired twisted pair digital link TE2 – connect through TA TE2 – connect through TA  Terminal Adapter (TA) -- either a stand-alone device or a board inside TE2  Network Termination 1 (NT1) – physical and electrical termination  Network Termination 2 (NT2) – intelligent devices for switching and concentration

 Circuit-switched capabilities : 64-kbps  Packet-switching capabilities : as provided by other data networks.  Frame-mode capabilities : supporting frame relay  Common-channel signaling capabilities : used to control the network and provide call management.

 Narrowband ISDN  Broadband ISDN 2 Generations of ISDN

 Bearer-channel (B-channel) :  Carry user "conversations" from a telephone, a computer, a fax.  Carries voice and data at 64 Kbps.  Supports circuit-switched, packet-switched, frame mode and semi permanent connections.

 Delta-channel (D-channel) :  Carries signaling information to control circuit switched calls on B-channel.  Can be used for a data transmission communication at a lower data rate.  16Kbps / 64Kbps  Carry low-speed data applications. (e.g., videotex, telemetry) (e.g., videotex, telemetry)

 High-speed channel (H-channel) :  Can be used as a single trunk or subdivided by the user.  Fast fax, video, high-speed data, high- quality audio and multiplexed information streams at lower data rates.  384Kbps(H0), 1536Kbps(H11), 1920 Kbps(H12)

 There are 2 types of ISDN interfaces:  Basic Rate Interface (BRI) – intended for home use.  Primary Rate Interface (PRI) – intended for business.

 Basic Rate Interface (BRI) :  Consists of two B-channels for data at 64 Kbps and one D-channel for control and signaling at 16 Kbps (2B + D).  2 x 64 Kbps + 16 Kbps = 144 Kbps (not including overhead), total 192 Kbps (including 48 Kbps overhead).  Designed to operate using the average local copper pair

 Basic Rate Interface (BRI) : cont’  BRI can carry a wide and flexible range of communications. communications.  A single BRI, for example, can carry two simultaneous voice or data conversations simultaneous voice or data conversations

 Primary Rate Interface (PRI) :  Consists of one 64 Kbps D-channel for signaling and 23 B-channels (23B + D).  23 x 64 Kbps + 64 Kbps = Mbps (not including overhead)  In Europe Mbps - either 30 or 31 64Kbps B-channels, or one 64Kbps D-channel - thus 30B+D or 31B+D.

 Primary Rate Interface (PRI) : cont’  In United States and Japan, consists of Kbps B-channels and one 64 Kbps D-channel, Kbps B-channels and one 64 Kbps D-channel, or 23B+D with a total bandwidth of 1.544Mbps. or 23B+D with a total bandwidth of 1.544Mbps.  PRI for larger users.

Layered ISDN Protocol

Conclusion  3 types of channels : B, D, and H channels  2 types of ISDN interfaces : BRI and PRI  Benefits of ISDN  3 layers of protocol in ISDN

Q & A  1)What are the three types of channels in ISDN? channels in ISDN?  Bearer-channel (B-channel)  Delta-channel (D-channel)  High-speed channel (H-channel)

 2) What are the two types of ISDN interfaces? interfaces?  Basic Rate Interface (BRI)  Primary Rate Interface (PRI)  3) What is B-channel?  carries circuit switched voice and/or data communications at speeds up to 64 kbps.  Bearer channel -- basic user channel.

 4) What are the 3 layers of protocol in ISDN? protocol in ISDN?  Layer 1 - Physical Layer  Layer 2 - Data Link Layer  Layer 3 - Network Layer

 5) What are the 2 generations of ISDN?  Narrowband ISDN  Broadband ISDN

 6)Who will get the benefits of ISDN?  user  network providers  manufacturers  enhanced service providers

Reference     stem/HTML/Module10/ISDN+ATM-4.html stem/HTML/Module10/ISDN+ATM-4.html stem/HTML/Module10/ISDN+ATM-4.html  

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