Signalling System No. 7wikipedia
Signaling System No. 7 (SS7) is a set of telephony signaling protocols developed in 1975, which is used to set up and tear down most of the world's public switched telephone network (PSTN) telephone calls.
SS7SS7 networkCCS7Signaling System #7 (SS7)entirely digitalSignaling System #7SS7 protocolsQ.713SS#7SS7

SMS

SMSshort message servicetext message
It also performs number translation, local number portability, prepaid billing, Short Message Service (SMS), and other mass market services.
The Mobile Application Part (MAP) of the SS7 protocol included support for the transport of Short Messages through the Core Network from its inception.

SIGTRAN

SigTran
The Internet Engineering Task Force (IETF) has defined the SIGTRAN protocol suite that implements levels 2, 3, and 4 protocols compatible with SS7.
SIGTRAN is the name, derived from signaling transport, of the former Internet Engineering Task Force (IETF) working group that produced specifications for a family of protocols that provide reliable datagram service and user layer adaptations for Signaling System 7 (SS7) and ISDN communications protocols.

Signaling (telecommunications)

signalsignalingsignalling
Signaling System No. 7 (SS7) is a set of telephony signaling protocols developed in 1975, which is used to set up and tear down most of the world's public switched telephone network (PSTN) telephone calls.
Out-of-band signaling has been used since Signaling System No. 6 (SS6) was introduced in the 1970s, and also in Signalling System No. 7 (SS7) in 1980 which became the standard for signaling among exchanges ever since.

Local number portability

local number portabilitynumber portabilityported
It also performs number translation, local number portability, prepaid billing, Short Message Service (SMS), and other mass market services. Other examples include Intelligent Network and local number portability databases.
Providers use SS7 to route calls throughout the US/Canada network.

ISDN User Part

ISUP
The Telephone User Part (TUP) was adopted in Europe and the Integrated Services Digital Network (ISDN) User Part (ISUP) adapted for public switched telephone network (PSTN) calls was adopted in North America. OSI layers 1 to 3 are provided by the Message Transfer Part (MTP) and the Signalling Connection Control Part (SCCP) of the SS7 protocol (together referred to as the Network Service Part (NSP)); for circuit related signaling, such as the BT IUP, Telephone User Part (TUP), or the ISDN User Part (ISUP), the User Part provides layer 7.
The ISDN (Integrated Services Digital Network) User Part or ISUP is part of Signaling System No. 7 (SS7), which is used to set up telephone calls in the public switched telephone network (PSTN).

Public switched telephone network

public switched telephone networkPSTNtelephone network
Signaling System No. 7 (SS7) is a set of telephony signaling protocols developed in 1975, which is used to set up and tear down most of the world's public switched telephone network (PSTN) telephone calls. The Telephone User Part (TUP) was adopted in Europe and the Integrated Services Digital Network (ISDN) User Part (ISUP) adapted for public switched telephone network (PSTN) calls was adopted in North America.
Later, more sophisticated address signaling, including multi-frequency signaling methods, enabled direct-dialed long distance calls by subscribers, culminating in the Signalling System 7 (SS7) network that controlled calls between most exchanges by the end of the 20th century.

Stream Control Transmission Protocol

SCTP
it is layered on the Stream Control Transmission Protocol (SCTP) transport mechanism.
The designers of SCTP originally intended it for the transport of telephony (Signaling System 7) over Internet Protocol, with the goal of duplicating some of the reliability attributes of the SS7 signaling network in IP. This IETF effort is known as SIGTRAN.

Signal Transfer Point

signal transfer pointSignal Transfer Point (STP)signalling transfer points
When operating in the quasi-associated mode, SS7 signaling progresses from the originating switch to the terminating switch, following a path through a separate SS7 signaling network composed of signal transfer points. The network can be made up of several link types (A, B, C, D, E, and F) and three signaling nodes – Service Switching Points (SSPs), Signal Transfer Points (STPs), and Service Control Points (SCPs).
A Signal Transfer Point (STP) is a router that relays SS7 messages between signaling end-points (SEPs) and other signaling transfer points (STPs).

Message Transfer Part

MTPQ.710MTP layer 3
OSI layers 1 to 3 are provided by the Message Transfer Part (MTP) and the Signalling Connection Control Part (SCCP) of the SS7 protocol (together referred to as the Network Service Part (NSP)); for circuit related signaling, such as the BT IUP, Telephone User Part (TUP), or the ISDN User Part (ISUP), the User Part provides layer 7.
The Message Transfer Part (MTP) is part of the Signaling System 7 (SS7) used for communication in Public Switched Telephone Networks.

Service control point

service control pointSCPgsmSCP
The network can be made up of several link types (A, B, C, D, E, and F) and three signaling nodes – Service Switching Points (SSPs), Signal Transfer Points (STPs), and Service Control Points (SCPs).
Standard SCPs in the telecom industry today are deployed using SS7, SIGTRAN or SIP technologies.

Mobile Application Part

MAP
TCAP provides transaction capabilities to its Users (TC-Users), such as the Mobile Application Part, the Intelligent Network Application Part and the CAMEL Application Part.
The Mobile Application Part (MAP) is an SS7 protocol that provides an application layer for the various nodes in GSM and UMTS mobile core networks and GPRS core networks to communicate with each other in order to provide services to users.

Intelligent Network

intelligent networkINIntelligent Network (IN)
Other examples include Intelligent Network and local number portability databases.
IN is supported by the Signaling System #7 (SS7) protocol between network switching centers and other network nodes owned by network operators.

Integrated Services Digital Network

ISDNintegrated services digital network ISDN
The Telephone User Part (TUP) was adopted in Europe and the Integrated Services Digital Network (ISDN) User Part (ISUP) adapted for public switched telephone network (PSTN) calls was adopted in North America.
Between telephone company switches, the signaling is performed via SS7.

Telephone User Part

TUP
The Telephone User Part (TUP) was adopted in Europe and the Integrated Services Digital Network (ISDN) User Part (ISUP) adapted for public switched telephone network (PSTN) calls was adopted in North America. OSI layers 1 to 3 are provided by the Message Transfer Part (MTP) and the Signalling Connection Control Part (SCCP) of the SS7 protocol (together referred to as the Network Service Part (NSP)); for circuit related signaling, such as the BT IUP, Telephone User Part (TUP), or the ISDN User Part (ISUP), the User Part provides layer 7.
Telephone User Part (TUP) provides conventional PSTN telephony services across the Signalling System No. 7 (SS7) network.

Telephony

telephonydigital telephonytelephone
Signaling System No. 7 (SS7) is a set of telephony signaling protocols developed in 1975, which is used to set up and tear down most of the world's public switched telephone network (PSTN) telephone calls.

Business telephone system

PBXprivate branch exchangekey telephone system
This is the case for earlier analogue trunks, multi-frequency (MF) and R2 digital trunks, and DSS1/DASS PBX trunks.
For the option to call from IP network to the circuit-switched PSTN (SS7/ISUP), the hosted solutions include interconnecting media gateways.

SS7 probe

*SS7 probe
An SS7 probe is a physical device to obtain signalling and/or bearer information from a telecommunications network, such as the PSTN or a corporate telephone system.

DS0A

In Europe they are usually one (64 kbit/s) or all (1,984 kbit/s) timeslots (DS0s) within an E1 facility; in North America one (56 or 64 kbit/s) or all (1,536 kbit/s) timeslots (DS0As or DS0s) within a T1 facility.
DS0A is the interface most commonly used for SS7 networks in the US. It is a 56/64kbit/s channel typically located in a DS1 or larger facility.

Blue box

blue box2600 Hzblue boxes
As the bearer channel was directly accessible by users, it was exploited with devices such as the blue box, which played the tones required for call control and routing.
The death of blue boxing came in the mid-to-late 1990s when telephone companies, becoming aware of the problem, eventually moved to out-of-band signaling systems with separate data and signalling channels (such as CCIS and SS7).

Multi-frequency signaling

multi-frequencyMFmultifrequency
This is the case for earlier analogue trunks, multi-frequency (MF) and R2 digital trunks, and DSS1/DASS PBX trunks. SS5 and earlier systems used in-band signaling, in which the call-setup information was sent by playing special multi-frequency tones into the telephone lines, known as bearer channels.
MF and other in-band signaling systems differ from Signaling System 7 (SS7) in that the routing digits are out-pulsed in MF format in the same voiceband channel used for voice.

INAP

Intelligent Network Application PartIntelligent Network Application Part (INAP)
TCAP provides transaction capabilities to its Users (TC-Users), such as the Mobile Application Part, the Intelligent Network Application Part and the CAMEL Application Part.
It is part of the Signalling System No. 7 (SS7) protocol suite, typically layered on top of the Transaction Capabilities Application Part (TCAP).

Telephone exchange

telephone exchangeexchangescentral office
When operating in the quasi-associated mode, SS7 signaling progresses from the originating switch to the terminating switch, following a path through a separate SS7 signaling network composed of signal transfer points. Due to its richness and the need for an out-of-band channel for its operation, SS7 is mostly used for signaling between telephone switches and not for signaling between local exchanges and customer-premises equipment.
Before Signalling System 7, Bell System electromechanical switches in the United States communicated with one another over trunks using a variety of DC voltages and signaling tones.

Transaction Capabilities Application Part

TCAP
The Transaction Capabilities Application Part (TCAP) is the primary SCCP User in the Core Network, using SCCP in connectionless mode.
Transaction Capabilities Application Part, from ITU-T recommendations Q.771-Q.775 or ANSI T1.114 is a protocol for Signalling System 7 networks.

Signalling Connection Control Part

SCCPNSP
OSI layers 1 to 3 are provided by the Message Transfer Part (MTP) and the Signalling Connection Control Part (SCCP) of the SS7 protocol (together referred to as the Network Service Part (NSP)); for circuit related signaling, such as the BT IUP, Telephone User Part (TUP), or the ISDN User Part (ISUP), the User Part provides layer 7.
The Signalling Connection Control Part (SCCP) is a network layer protocol that provides extended routing, flow control, segmentation, connection-orientation, and error correction facilities in Signaling System 7 telecommunications networks.

Service switching point

Service Switching PointMSSPService Switching Points
The network can be made up of several link types (A, B, C, D, E, and F) and three signaling nodes – Service Switching Points (SSPs), Signal Transfer Points (STPs), and Service Control Points (SCPs).
The service switching point uses the Signalling System No. 7 (SS7) protocols which are responsible for the call setup, management, and termination with other service switching points.