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Signaling NetworkIt consists of a set of reserved or dedicated channels known as signaling links
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Service Switching Points (SSPs) originate or
terminate a call and communicate on the signalling
network with Service Control Points (SCPs) to
determine how to route a call or set up and managesome special feature.
Traffic on the signaling network is routed by packet
switches called Signal Transfer Points (STPs).
SCPs and STPs continuously communicate with each
other to ensure that service can continue if one
network point fails.
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Intelligent Network (IN)
• An enhanced signalling network
• Provides an array of services (e.g., caller ID,
personal ID enabling mobility, call back, …)
• Except the basic switching functions, all othersignalling operations are shifted to SCP (Service
Control Points) in the signalling network.
• Allows introduction of new services withoutchanging the hardware/software of switching
vendors.
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Intelligent Network (IN)
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Signaling System #7
Architecture
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SS7 uses out-of-band signaling,which means that signaling (control)
information travels on a separate,
dedicated 56 or 64 Kbps channelrather than within the same channel
as the telephone call.
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ISDN(Integrated Services Digital Network)
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ISDN
• a switched digital telecommunication line
that can be delivered over regular copper
wires
• provides end-to-end digital
communications
• Can be obtained from a local telephone
company in the same way an analog
connection is obtained
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ISDN
• There are two different types of ISDN
services that are widely available
• Basic Rate Interface (BRI)
– Used for home or SOHO (small office/Home
Office) connection
• Primary Rate Interface (PRI)
– Used in large businesses
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Evolution of ISDN
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Voice over Analog Network
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Voice and Data over Analog Network
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Analog and Digital Services
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Integrated Digital Network
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Integrated Services Digital Network
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Basic Rate Interface
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Primary Rate Interface
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Functional Grouping
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Figure 15-10
Reference Points
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ISDN specifies a number of reference points that define
logical interfaces between functional groups, such as TAsand NT1s.
R - The reference point between non-ISDN equipment and
a TA.S - The reference point between user terminals and the
NT2.
T - The reference point between NT1 and NT2 devices.
U - The reference point between NT1 devices and line-
termination equipment in the carrier network.
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ISDN terminals come in two types:
1. Specialized ISDN terminals are referred to as terminalequipment type 1 (TE1).
2. Non-ISDN terminals, such as DTE, that predate the ISDN
standards are referred to as terminal equipment type 2
(TE2).
TE1s connect to the ISDN network through a four-wire,
twisted-pair digital link. TE2s connect to the ISDN network
through a TA. The ISDN TA can be either a standalone
device or a board inside the TE2.
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Beyond the TE1 and TE2 devices, the next connection
point in the ISDN network is the network termination type 1
(NT1) or network termination type 2 (NT2) device. These
are network-termination devices that connect the four-wiresubscriber wiring to the conventional two-wire local loop.
In North America, the NT1 is a customer premises
equipment (CPE) device. In most other parts of the world,
the NT1 is part of the network provided by the carrier.
The NT2 is a more complicated device that typically is
found in digital private branch exchanges (PBXs) and that
performs Layer 2 and 3 protocol functions andconcentration services.
An NT1/2 device also exists as a single device that
combines the functions of an NT1 and an NT2.
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BRI Interfaces
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PRI Interfaces
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B-ISDN would be able to provide end users with increasedtransmission rate,up to 155.54Mbits/s on a switching basis.
… is to offer subscribers a large variety of services such as
video telephony, video surveillance, high volume file
transfer, High Definition Television(HDTV) and many more
services not offered by ISDN.
.. is designed to use ATM technology over fiber optic
cables.
Broadband Integrated Services Digital Network
(B-ISDN)
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