This document discusses Integrated Services Digital Network (ISDN), which is a set of communication standards that allows the digital transmission of multiple services such as voice, video, and data over traditional telephone networks. Some key points: - ISDN was first introduced in 1988 and aimed to standardize subscriber interfaces and network capabilities. - It provides faster transmission speeds of 64 kbps and allows simultaneous transmission of voice and data. - ISDN uses terminal adapters, network termination equipment, and reference points to connect user terminals to the network. - There are basic and primary rate interfaces that support different transmission speeds.

2. Set of communications standards for simultaneous
digital transmission of voice, video, data, and other
network services defined as ISDN(circuit switched
telephone system)
 First introduced in 1988.
 Its emergence represents an effort to standardize
subscriber services, user/network interfaces, and
network and internetwork capabilities
 Provides access to packet switched networks.
 Simultaneous transmission of voice and data.
 Provides faster rate transmission at 64kbps.
 High speed file transfer
 Additional telephone lines to serve the
telecommuting industry.
 Video conferencing

3. Carries a variety of user traffic, such as digital
video, data, and telephone network
services, using the normal phone circuit-
switched network
 Offers much faster call setup than modems
by using out-of-band signaling (D channel)
Often less than one second
 Provides a faster data transfer rate than
modems by using the 64-kbps bearer channel
(B channel)
Can combine multiple B channels to bandwidth of
128 kbps
 Can negotiate PPP links

4. Terminal adapters (TAs),network-termination devices,
line-termination equipment, and exchange-termination equipment.
ISDN
TERMINALS
Termination
equipment1(TE1)
Termination
Equipment2(TE2)
ISDN
NETWORK
Network
Termination1(NT1)
Network
Termination(NT2)
TERMINALS
NETWORK
REFERENCE POINTS
U:Two wire cable which connects customer
equipment with the telecommunication
provider
R:Between non ISDN equipment & TA
S:Between user terminals and NT2
T:Reference point between NT2 & NT1 devices

6. DATA LINK LAYER
PHYSICAL LAYER

8. BASIC RATE INTERFACE
PRIMARY RATE INTERFACE

9. It is a method that enables several users on a network to
access the Internet via ISDN. It is also known as an ISDN LAN
modem.
it contains a BRI ISDN port and an Ethernet port.
It has access to the unit for configuration and monitoring is
typically done via a Telnet connection or Web browser or
both.

10. Static
Routers
Dynamic
Routing
Dial on
Demand
Routers
Router
Spoofing
Snapshot
Routing

11. Routing technique
where a network
connection to a remote
site is established only
when needed.
Do not need
permanent, continuous
links between sites on the
WAN
The connection only
active when data is sent
to the remote site
otherwise the link is
disconnected.
Used in order to save the
costs of a dedicated
WAN line for
organizations that do not
need permanent
continuous connection.
DDR is mainly used for
backup connections
which go live when the
primary connection fails.

12. DDR operation is based on two main connection as follows:
PHYSICAL
CONNECTION
• consists of the actual cable that connects
computers on the network and the network
interface card uses existing Public Switched
Telephone Network(PSTN) lines
DIGITAL
CONNECTION
• uses a Point-to-Point Protocol(PPP) link, which
handles all networking functions

13. Static routes eliminate the need to send routing updates over the ISDN link
which will trigger a DDR (Dial on Demand Router) call.

14. It is a routing update mechanism that eliminates the need for configuring
and maintaining large static tables and also cuts down the overhead of
these routing update.

15. Opposite to static routing. Dynamic routing describes the
capability of a system, through which routes are characterized
by their destination, to alter the path that the route takes
through the system in response to a change in conditions. The
adaptation is intended to allow as many routes as possible to
remain valid (that is, have destinations that can be reached) in
response to the change.

16. 1: When the call is
initiated, the D- channel
comes up. The called
number is sent to the local
ISDN switches.
2: the local switch use the
signaling system protocols
to set up a path and pass
the called number to the
terminating ISDN switch.
3: The far end switch brings
up the D to the
destination. The D channel
is used for call setup
signaling and call
termination which are the
call control functions.
4: When the terminating end
answers, the B channel is
connected end to end. The
B channel carries data and
both the B channels can be
used simultaneously to the
same or different
destinations.

17.  Used heavily by the broadcast
industry
ISDN BRI services used to link
remote studios
ISDN via satellite is used by
field reporters
It is also common to use ISDN
for the return audio links to
remote satellite broadcast
vehicles.
 important backup network for
point-to-point leased line
customers
primarily used for voice and
fax traffic
Remote Access
(Telecommuters)
Remote Nodes (Voice and
Data)
SOHO Connectivity (Small
Branches)

18. Nowadays customers
use ISDN primarily as
a WAN backup
technology and to
provide remote
access to
telecommuters and
small offices. Many
organization and
service provider have
made significant
investment in ISDN
equipment and
training and plans to
continue leveraging
that investment.
Although ISDN boasts a much faster call setup and higher
output than POTS, many potential BRI customers are turning
to digital subscriber line (DSL) and cable technologies which
offer much higher output at lower cost. Despite these
emerging technologies, ISDN still remains a viable remote
access solution.