Transcript ISDN - Sharif

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
S/T interface
TE2
Analog devices:
phone, Fax III,...
TA
Rate adaptation
NT1
2W
U interface
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
56 k Technology
Analog line
Digital line
Access server
Telephone
switch
Modem
?
Telephone
switch
<= 33,6 kbps
Telephone
switch
Modem
Modem
Access server
<= 56 kbps
<= 33,6 kbps
ISDN, E1,..
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
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Users need for LAN connections
– subscribe for PRI or BRI connection
– ISDN router (commercial, PC version with ISDN
Adapter,..)
Dial Up - Private
Internet
ISDN Access server
ISDN connection
Telephone
Network
PC with internal or external ISDN adapter
ISDN connection
Dial Up - LAN
Internet
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
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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
Subscriber
interface to
ISDN
Terminal
equipment
(TE)
>64kbps
non-switched
capabilities
>64kbps
switched
capabilities
Digital
subscriber
loop to
C. O.
Network
Termination
(NT)
64kbps
ckt non-switched
capabilities
ISDN
switch
>64kbps
ckt switched
capabilities
Packet switched
capabilities
User-network
signaling
User-network
signaling
Frame mode
capabilities
Commonchannel signaling
capabilities
ISDN
switch
Subscriber
site or
service
provider
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
B
Basic Service:
Basic
Management rate: 192 kbps
Standard throughput: 144 kbps
Composition: B + B + D channels,
+ Synch & framing
D
Information:
Voice, Data
Signaling:
Overhead or
telemetry, etc.
B
B PCM voice
channels
Primary Service:
Primary
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
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References - URL’s
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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