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
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