1 CIRCUIT SWITCHING - SIGNALING Introduction
Apr 07, 2016
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CIRCUIT SWITCHING -SIGNALING
Introduction
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Introduction
Introduction
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Introduction
Introduction
Residential customer
Business customer
Residential customer
Business customer
Class 1: regional centers
Class 2: sectional centers
Class 3: primary centers
Class 4: toll centers
Class 5: local central office
Local loops
Tandem office
Local loops
Local Carrier's Domain of Influence, Intra-LATA
Class 1: regional centers
Class 2: sectional centers
Class 3: primary centers
Class 4: toll centers
Class 5: local central office
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Introduction
LATA – Local Access and Transport AreaIC – Interexchange Carrier
Introduction
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Numbering Plan
Numbering Plan - Example
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Numbering Plan - Example
Signaling
Intra-exchange signaling (Subscriber Signaling)
Inter-exchange signaling (Signaling between exchange)
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Subscriber signaling
Subscriber Signaling
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Subscriber SignalingLine Signaling
Subscriber SignalingLine Signaling
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Subscriber SignalingAddress Signaling
Subscriber SignalingAddress Signaling
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Subscriber SignalingRinging Signaling
Subscriber SignalingTones and Announcements
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Subscriber SignalingTones and Announcements
Subscriber SignalingTones and Announcements
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Subscriber SignalingTones and Announcements for Supplementary services
Supplementary services
Customer Calling Services
Customer Local Area Signaling Services (CLASS)
Subscriber SignalingTones and Announcements for Supplementary services
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Subscriber SignalingTones and Announcements for Supplementary services
Subscriber SignalingTones and Announcements for Supplementary services
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Subscriber SignalingTones and Announcements for Supplementary services
Subscriber SignalingTones and Announcements for Supplementary services
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Subscriber SignalingTones and Announcements for Supplementary services
Inter-Exchange Signaling
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Inter-Exchange Signaling
Inter-Exchange signaling
Channel-Associated inter-exchange Signaling (CAS) – per trunk signaling
Common Channel Signaling (CCS)
Inter-Exchange Signaling
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Inter-Exchange SignalingChannel-Associated Signaling (CAS)
Inter-Exchange SignalingChannel-Associated Signaling (CAS)
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Inter-Exchange SignalingChannel-Associated Signaling (CAS)
Inter-Exchange SignalingChannel-Associated Signaling (CAS)
Channel-Associated Signaling systems:
Bell System multi-frequency (MF) signaling
CCITT No. 5 signaling
R2 signaling
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Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
R2 signaling Known as multi-frequency compelled (MFC), MFC-R2 or
R2 signaling system
Can be used on 2-wire analog trunks; 4-wire analog and digital trunks
Can not be used on TASI-equiped trunks and trunks carried by satellite transmission systems -->Application of R2 is limited to relative short international trunks
Most important difference between R2 and Bell MFC & CCITT No.5 is its register (address) signaling
Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
Supervision signaling on digital trunks
Network (national/international R2 signaling) use E1 for digital trunks
Super-frame consists of 16 consecutive frames, numbered from 0 to 15
For super-frame alignment, bit 1 – 4 in TS16 of frame 0 are coded 0000
TS16 in frame 1 to 15 carries 4 status bits for the trunks
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Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
Supervision signaling on digital trunks
Supervision signaling for digital international R2 trunks is continuous
2 forward and 3 backward trunk states, represented by bit af, bf and ab, bb
respectively
Bit c & d are not used and set to 0 and 1
Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
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Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
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Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
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Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
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Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
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Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
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Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
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Inter-Exchange SignalingChannel-Associated Signaling (CAS) – R2/MFC
Inter-Exchange SignalingCommon Channel Signaling (CCS)
Common channel signaling, introduced in 1976, was developed as an alternative form of call-control signaling for trunks.
In CCS, signaling information is not carried by the individual trunks
Signaling network transfer signaling messages between exchange
Signaling network consist of: Signaling Data Link (SDL)
Signaling Transfer Point (STP)
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Inter-Exchange SignalingCommon Channel Signaling (CCS)
Inter-Exchange SignalingCommon Channel Signaling (CCS)
Service Control Point (CSP) and an Operation, Administration & Maintenance (OAM) center also have signaling data links
Exchanges can send messages to, and receive messages, from these entities
Procedures that involve signaling between an exchange and a SCP, or between an exchange and a OAM center, are known as transactions
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Inter-Exchange SignalingCommon Channel Signaling (CCS)
An SCPs in a network support Intelligent Network (IN). These services require information that can not be store in a
exchange conveniently
The OAM centers allow centralized operation, administration and maintenance of the network, example Transaction in which OAM center requests an exchange to
test a particular trunk to report the test results
Transactions enable the OAM centers to verify and change subscriber and routing data that stored in the exchanges.
Inter-Exchange SignalingCommon Channel Signaling (CCS)
1st generation of CCS was introduced in 1970s Common Channel Interoffice Signaling (CCIS), defined by
Bell System
Signaling system No. 6, defined by CCITT
2nd generation: Signaling System 7 (SS7)
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Inter-Exchange SignalingCommon Channel Signaling (CCS) – SS7
SS7 Hierarchy Organized in 4-level Hierarchy
OSI Model Signalling System 7 Description/Function
Application
Presentation
Session
Transport
Network
Datalink
Physical
Operations Maintenance Application Part (O&MAP)
Transaction Capabilities Application Part (TCAP)
Network Service Part (NSP)
Signalling Connection Control Part (SCCP)
Message Transfer Part (MTP)
O&MAP provides standards for routing and management of messages related to network operations and maintenance
TCAP provides standards for routing and management of noncircuit related information for transaction processing applications requiring out-of-band signalling
Another term for the combination of the SCCP and the MTP3
SCCP provides standards for routing and management of signalling messages. Not related to call set-up between switches. A connection-oriented service providing reliable message delivery
MTP provides standards for routing of signalling messages between switches. A connectionless, datagram service
Protocol Name
O&MAP
TCAP
SSCP
MTP
Inter-Exchange SignalingCommon Channel Signaling (CCS) – SS7
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Inter-Exchange SignalingCommon Channel Signaling (CCS) – SS7
Inter-Exchange SignalingCommon channel Signaling – SS7
Message Transfer Part (MTP) – this protocol provides message transfer services for its user Divided into 3 parts: MTP1, MTP2, MTP3, that occupy level
1, 2 and 3 of SS7 hierarchy
A MTP user passes its outgoing messages to – and receives its incoming messages from – the MTP3 at its signaling point
A signaling has one MTP3
A combination of MTP1 & 2 represents a signaling link at a signaling point
A signaling point that terminates n signaling links has n of these combinations
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Inter-Exchange SignalingCommon channel Signaling – SS7
Telephone User Part (TUP) MTP user
Protocol for telephony call control and for trunk maintenance
Integrated Service User Part (ISUP) MTP user
Protocol for call control and trunk maintenance procedures in both the telephone network and the ISDN
Signaling Connection Control Part (SCCP) MTP user
Provide functions for the transfer of messages that are not trunk-related
Its users are ISUP and TCAP
Inter-Exchange SignalingCommon channel Signaling – SS7
Transaction Capability Application Part (TCAP) Transactions are operation that are not related to individual
trunks and involve 2 signaling point
TCAP protocol provides standard interface to TC-user (functions at signaling point)
TCAP is a user of SCCP
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Inter-Exchange SignalingCommon channel Signaling – SS7