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Services |
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ISDN
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What
is ISDN ?
Integrated
Services Digital Network (ISDN) is a state-of-the-art Public
Switched Digital Network for provisioning of different
services–voice, data & image transmission over the
telephone line through the telephone network.
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AVAILABILITY
ISDN service is available by and large in all major cities of India. Also ISDN has overseas connectivity with the following countries:
Australia, Austria, Belgium, Canada, Denmark, France, Germany, Ireland, Israel, Italy, Japan, Malaysia, Netherlands, Norway, Philippines, Singapore, Switzerland, Thailand,
U.A.E., UK, USA.
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SERVICES PROVIDED BY ISDN
The following services are offered on a dial-up basis between two ISDN subscribers:
(i) Desktop Video Conferencing on using three ISDN lines at 64/128 kbps.
(ii) High quality video conferencing by using three ISDN lines at 384 kbps
(iii) Video Telephony.
(iv) Teleconferencing which facilitates the transmission of pictures, documents and drawings
etc. apart from voice and images of the participants.
(v) High speed data transmission at 64/128 kbps.
(vi) High speed facsimile at 64/128 kbps with G4 Fax terminal.
(vii) Access to Internet with a higher bandwidth of 64/128 kbps giving
significantly improved response time and quality of service.
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SUPPLEMENTARY SERVICE
ISDN, being a Value Added Service,
offers many supplementary features/services:
(1) Calling Line Identification Presentation
(2) Advice of Charge
(3) Line Hunting
(4) Closed User Group
(5) User to User Signalling
(6) Call Waiting
(7) Call forwarding
On No Reply
On Busy
Unconditional
(8) Multiple Subscriber Number
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DIFFERENT KINDS OF ISDN TERMINALS
The ISDN telephone line is terminated on a common box called the Network Termination (NT) at the subscriber’s premises. The Network Termination unit along with accessories will be provided by the MTNL or can be procured by the subscriber. The terminal equipment
has to be procured by the subscriber himself from the open market. The terminal equipment should be TEC approved for the satisfactory working of ISDN.
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TYPE OF ISDN TERMINAL
(a) ISDN feature phone: this is a simplest type of ISDN phone which has an LCD display and some additional keys.
(b) Terminal adapter
(c) PC add-on ISDN card
(d) Video phone
(e) G4 fax
(f) G4 fax
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Benefits
of ISDN
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| 1. |
Single
connection can support both voice and data. |
| 2. |
High
quality services being digital right from subs, premises
(end to end). |
| 3. |
Eight
terminals can be connected on a single line. |
| 4. |
High
speed data transfer from PC to PC is possible – 64 Kbps
against existing 9.6 Kbps (6 times faster). |
| 5. |
Two
calls can be established simultaneously on a single pair of
wires. |
| 6. |
The
call set time is very short (1-2 seconds). |
| 7. |
A
number of supplementary services are supported like in pots. |
Calling
Line Identification, Call Forwarding, Call Forwarding on busy
signal, Call Forwarding on no reply, Call Forwarding unconditional,
Advice of Charge, Terminal Portability, Multiple Subscriber Number,
Closed User Group.
Benefits
of ISDN for Network Operators
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Avoidance
of separate networks for different services. |
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Economical
use of the equipment of the digitalized telephone network,
especially the copper pair of the subscriber line. |
| 3. |
Reduction
in costs due to simplified operation and maintenance
procedures. |
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How
is ISDN line superior to the phone line ?
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- The
signal on the ISDN line–voice or data, is sent in digital
mode.
- The
signal level at subscriber's terminal equipment is independent
of
line length.
- An
ISDN subscriber can establish two simultaneous independent calls
which could be voice, data, image or combination of any two
whereas
only one call is possible on ordinary telephone lines.
- The
call set-up time between two ISDN subscribers is extremely
short.
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Basic Services
Types