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Introduction to ISDN. Prepared by: Mehdi Kereshteh Payam Kaywan University of Science & Technology of Mazandaran 21/8/1384. What is ISDN?. ISDN - Integrated Services Digital Network Telephone services Telecommunication services Used for voice, image and data. ISDN protocols.
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Introduction to ISDN Prepared by: Mehdi Kereshteh Payam Kaywan University of Science & Technology of Mazandaran 21/8/1384
What is ISDN? • ISDN - Integrated Services Digital Network • Telephone services Telecommunication services • Used for voice, image and data
ISDN protocols • E - series for Telephone network and ISDN • I - series for ISDN concepts, aspects and interfaces
Fundamentals • Types of channels • Bearer channel (B-channel=64 kb/s) clear pipe for data • Delta channel (D-channel, 16 kb/s or 64 kb/s) call signaling information: • who is calling • type of call • calling what number
Fundamentals • Service types • Basic Rate Interface (2 B channels + 1 D channel (16 kb/s)) • Primary Rate Interface (30 B channels + 1 D channel (64 kb/s))
Advantages of ISDN • Digital • reliable connection • Speed • 128 kb/s (160 kb/s) for BRI • 1920 kb/s (2048 kb/s) for PRI • Fast call setup • 2 seconds
Advantages of ISDN (2) • Bandwidth on Demand • adding new channels to the bundle of channels • Multiple devices • phone, fax, PC, videoconferencing system, router, terminal adapter,.. each with its own sub-address
ISDN and OSI model • Layer1 - Physical • Layer2 - Data Link • Layer3 – Network
Interfaces and Devices (1) • Interfaces • S/T (4w) • U (2w) • Devices • NT1 • TE1 - ISDN devices • TE2 - analog devices (need TA) • TA - Terminal Adapter (rate adaptation (V.110, V.120)
Interfaces and Devices (2) ISDN devices TE1 4W 2W NT1 S/T interface U interface TE2 TA Analog devices: phone, Fax III,... Rate adaptation
ISDN Access Servers (1) • Digital modems (accepting analog and ISDN calls) • software busy-out feature • 56 kbit/s technologies • Rate adaptation (V.110, V.120,..) • Compression (Stack,..) • Synchronous PPP (with CHAP/PAP authentication)
ISDN Access Servers (2) • PPP Multilink • BACP (Bandwidth Allocation Control Protocol) • Controlling the number of B-channels per user • D-channel based callback • CLIP - Caller Line Identification Presentation
Telephone switch 56 k Technology Analog line Access server Digitalline Telephone switch Telephone switch ? Modem <= 33,6 kbps Modem Access server Modem <= 56 kbps ISDN, E1,.. <= 33,6 kbps
56 k Prerequisites • Only one analogue/digital conversion • less noise and faster digital lines • Digital Access Server • Same technology in Access Server and in dial-up modem • 56K Flex from Lucent Technologies and Rockwell • X2 from U.S. Robotics, Texas Instruments and Cirrus Logic • V.90 - ITU-T standard (to be confirmed in 9/98)
56 k Considerations • 56 k not reached in reality • 45 kbps practical maximum • Cost for upgrading equipment to ITU-T standard
Using ISDN for IP Data Networks (1) • Characteristics • Speed • Fast call setup • Bandwidth on Demand
Using ISDN for IP Data Networks (2) • Modes of Usage • Dial Up (LAN or host) • Bandwidth on Demand • Backup lines • Permanent connections
Dial Up • Providers need: • subscribe for PRI connections or multiple BRI connections • ISDN Access Server
Dial Up • Users need for host connections: • subscribe for BRI connection • ISDN Adapter • Users need for LAN connections • subscribe for PRI or BRI connection • ISDN router (commercial, PC version with ISDN Adapter,..)
Internet Dial Up - Private ISDN Access server ISDNconnection Telephone Network ISDNconnection PC with internal or external ISDN adapter
Internet Dial Up - LAN ISDN Access Server LAN ISDN connection Telephone Network ISDN connection ISDN router
ISDN Adapters • Internal/external • Active/passive (for internal) • Integrated NT • Plug for telephone line • Integrated modem • Synchronous PPP (with CHAP/PAP authentication)
ISDN Adapters 2 • PPP Multilink • Rate adaption (V.110, V.120,..) • CAPI • Compression (Stac,…)
ISDN Routers • Integrated NT • Plug for telephone line • Integrated modem • Synchronous PPP (with CHAP/PAP authentication) • PPP Multilink • Compression (Stac,…) • Tariff management
Bandwidth on Demand • Router to router connections • ISDN call setup when leased line overloaded
Backup lines • Router to router connections • ISDN call setup when leased line fails
Equipment • ALL EQUIPMENT COMPATIBLE with existing national ISDN services • Test new equipment first
ISDN Architecture Network Subscriber premises >64kbps non-switched capabilities >64kbps switched capabilities Digital subscriber loop to C. O. Subscriber interface to ISDN 64kbps ckt non-switched capabilities Network Termination (NT) Subscriber site or service provider Terminal equipment (TE) >64kbps ckt switched capabilities ISDN switch ISDN switch Packet switched capabilities User-network signaling Frame mode capabilities Common- channel signaling capabilities User-network signaling
Transmission Structure • B Channel: 64 kbps • D Channel: 16 or 64 kbps • H Channel: 384 (H0), 1536 (H1), or 1920 (H12) kbps • Basic Rate Interface • Primary Rate Interface
ISDN Channel Structures B Information: Voice, Data B Basic Signaling: Overhead or telemetry, etc. Basic Service: Management rate: 192 kbps Standard throughput: 144 kbps Composition: B + B + D channels, + Synch & framing D B B PCM voice channels Primary Primary Service: Rate: 1.544/2.048 Mbps Composition: 2.048 Mbps: 30 B at 64 kbps each 2 D at 64 kbps 1.544 Mbps: 23 B at 64 kbps each 1 D at 64 kbps B D Signaling
Ordering ISDN connections • With or without NT1 • Type of NT (NT1, NT1+2ab,…) • Types of B-channels (data, voice,both) • Usage of D-channel packet data • CLIP (Calling Line Identification Presentation) • Standard or comfort services
National ISDN variations • USA: 5ESS/DMS100/NI-1/NI-2 • Europe: NET3 • France: VN2/VN3/NET33 • Germany: 1TR6/NET3 • Japan • Australia
References - URL’s • http://www.alumni.caltech.edu/~dank/isdn/ • for RFCs: http://www.alumni.caltech.edu/~dank/isdn/isdn_ai.html#RFCS • http://www.data.com • http://www.pacbell.com/products/business/fastrak/networking/isdn/info/isdn-guide • http://www.adtran.com/support/isu/mpfaq.html