ISDN

1
ISDN

• Ksenija Furman Jug
• ARNES
• ksenija.furman_at_arnes.si

2
Why ISDN?

• ISDN - Integrated Services Digital Network
• Telephone services -gt Telecommunication services
• Used for voice, image and data

3
ISDN protocols

• E - series for Telephone network and ISDN
• I - series for ISDN concepts, aspects and
  interfaces

4
ISDN and OSI model

• Layer 1 - Physical (2B1Q)
• Layer 2 - Data Link (Q.920 - Q.923)
• Layer 3 - Network (Q.930 - Q.939)

5
Fundamentals

• Types of channels
• Bearer channel (B-channel64 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

6
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))

7
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

8
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 subaddress

9
Interfaces and Devices
ISDN devices
TE1
2W
4W
NT1
S/T interface
U interface
TE2
TA
Analog devices phone, Fax III,...
Rate adaptation
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Interfaces and Devices

• 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)

11
Using ISDN for IP Data Networks

• Characteristics
• Speed
• Fast call setup
• Bandwidth on Demand

12
Using ISDN for IP Data Networks

• Modes of Usage
• Dial Up (LAN or host)
• Bandwidth on Demand
• Backup lines
• Permanent connections

13
Dial Up

• Providers need
• subscribe for PRI connections or multiple BRI
  connections
• ISDN Access Server

14
ISDN Access Servers

• Digital modems (accepting analog and ISDN calls)
• software busy-out feature
• 56 kbit/s technologies
• Rate adaption (V.110, V.120,..)
• Compression (Stac,..)
• Synchronous PPP (with CHAP/PAP authentication)

15
ISDN Access Servers 2

• PPP Multilink
• BACP
• Controlling the number of B-channels per user
• D-channel based callback
• CLIP - Caller Line Identification Presentation

16
56 k Technology
Analog line
Access server
Digital line
Telephone switch
Telephone switch
?
Modem
lt 33,6 kbps
Modem
Access server
Modem
lt 56 kbps
ISDN, E1,..
lt 33,6 kbps
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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
• K56Flex from Lucent Technologies and Rocwell
• X2 from U.S. Robotics, Texas Instruments and
  Cirrus Logic

18
56 k Considerations

• 56 k not reached in reality
• 43 kbps practical maximum
• Cost for upgrading equipment to ITU standard

19
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,..)

20
Dial Up - Private
ISDN Access server
ISDN connection
Telephone Network
ISDN connection
PC with internal or external ISDN adapter
21
Dial Up - LAN
ISDN Access Server
LAN
ISDN connection
Telephone Network
ISDN connection
ISDN router
22
ISDN Adapters

• Internal/external
• Active/passive (for internal)
• Integrated NT
• Plug for telephone line
• Integrated modem
• Synchronous PPP (with CHAP/PAP authentication)

23
ISDN Adapters 2

• PPP Multilink
• Rate adaption (V.110, V.120,..)
• CAPI
• Compression (Stac,)

24
ISDN Routers

• Integrated NT
• Plug for telephone line
• Integrated modem
• Synchronous PPP (with CHAP/PAP authentication)
• PPP Multilink
• Compression (Stac,)
• Tarrif management

25
Bandwidth on Demand

• Router to router connections
• ISDN call setup when leased line overloaded

26
Backup lines

• Router to router connections
• ISDN call setup when leased line fails

27
Equipment

• ALL EQUIPMENT COMPATIBLE with existing national
  ISDN services
• Test new equipment first

28
Ordering ISDN connections

• With or without NT1
• Type of NT (NT1, NT12ab,)
• Types of B-channels (data, voice,both)
• Usage od D-channel packet data
• CLIP (Calling Line Identification Presentation)
• Standard or comfort services

29
National ISDN variations

• USA 5ESS/DMS100/NI-1/NI-2
• Europe NET3
• France VN2/VN3/NET33
• Germany 1TR6/NET3
• Japan
• Australia

30
References - URLs

• http//www.alumni.caltech.edu/dank/isdn/
• for RFCs http//www.alumni.caltech.edu/dank/isdn
  /isdn_ai.htmlRFCS
• http//www.data.com
• http//www.pacbell.com/products/business/fastrak/n
  etworking/isdn/info/isdn-guide
• http//www.adtran.com/support/isu/mpfaq.html