Service Control Point
Encyclopedia
A service control point (SCP) is a standard component of the Intelligent Network
(IN) telephone system which is used to control the service. Standard SCPs in the telecom industry today are deployed using SS7
, Sigtran or SIP
technologies. The SCP queries the service data point
(SDP) which holds the actual database and directory. SCP, using the database from the SDP, identifies the geographical number to which the call is to be routed. This is the same mechanism that is used to route 800 numbers.
SCP may also communicate with an intelligent peripheral (IP) to play voice messages, or prompt for information to the user, such as prepaid long distance using account codes. This is done by implementing telephone feature codes like "#", which can be used to terminate the input for a user name or password or can be used for call forwarding
. These are realized using Intelligent Network Application Part
(INAP) that sits above Transaction Capabilities Application Part
(TCAP) on the SS7 protocol stack. The TCAP is part of the top or 7th layer of the SS7 layer breakdown.
SCPs are connected with either SSPs
or STPs
. This is dependent upon the network architecture that the network service provider wants. The most common implementation uses STPs.
SCP and SDP split is becoming a common industry practice. This is known generally in the industry by split architecture. Reason is that operators want to decouple the dependency between the two functionality to facilitate upgrades and possibly rely on different vendors.
Intelligent network
The Intelligent Network , is the standard network architecture specified in the . It is intended for fixed as well as mobile telecom networks...
(IN) telephone system which is used to control the service. Standard SCPs in the telecom industry today are deployed using SS7
SS7
SS-7 can stand for:* Signaling System #7, a set of telephone signaling protocols.* The R-16 missile, with NATO reporting name SS-7 Saddler.* China Railways SS7, an electric locomotive model in China.* Super Socket 7, a chip socket introduced by AMD...
, Sigtran or SIP
Session Initiation Protocol
The Session Initiation Protocol is an IETF-defined signaling protocol widely used for controlling communication sessions such as voice and video calls over Internet Protocol . The protocol can be used for creating, modifying and terminating two-party or multiparty sessions...
technologies. The SCP queries the service data point
Service Data Point
A service data point is the node in the IN GSM which is responsible for providing subscriber information. A GSM network element that needs information about subscriber will interrogate the SDP about such information....
(SDP) which holds the actual database and directory. SCP, using the database from the SDP, identifies the geographical number to which the call is to be routed. This is the same mechanism that is used to route 800 numbers.
SCP may also communicate with an intelligent peripheral (IP) to play voice messages, or prompt for information to the user, such as prepaid long distance using account codes. This is done by implementing telephone feature codes like "#", which can be used to terminate the input for a user name or password or can be used for call forwarding
Call forwarding
Call forwarding , in telephony, is a feature on some telephone networks allowing an incoming call to a called party to be redirected to a third party. For example, the third party may be a mobile telephone, voicemail box or other telephone number where the desired called party is situated. It was...
. These are realized using Intelligent Network Application Part
INAP
The Intelligent Network Application Part is a signalling protocol used in the intelligent network architecture. It is part of the SS7 protocol suite, typically layered on top of TCAP.It can also be termed as logic for controlling telecommunication services migrated from traditional switching...
(INAP) that sits above Transaction Capabilities Application Part
Transaction Capabilities Application Part
Transaction Capabilities Application Part, from ITU-T recommendations Q.771-Q.775 or ANSI T1.114 is a protocol for Signalling System 7 networks. Its primary purpose is to facilitate multiple concurrent dialogs between the same sub-systems on the same machines, using Transaction IDs to differentiate...
(TCAP) on the SS7 protocol stack. The TCAP is part of the top or 7th layer of the SS7 layer breakdown.
SCPs are connected with either SSPs
Service switching point
In telephony, a service switching point is the telephone exchange that initially responds, when a telephone caller dials a number, by sending a query to a central database called a service control point so that the call can be handled...
or STPs
Signal Transfer Point
A Signal Transfer Point is a router that relays SS7 messages between signaling end-points and other signaling transfer points . Typical SEPs include service switching points and service control points . The STP is connected to adjacent SEPs and STPs via signaling links...
. This is dependent upon the network architecture that the network service provider wants. The most common implementation uses STPs.
SCP and SDP split is becoming a common industry practice. This is known generally in the industry by split architecture. Reason is that operators want to decouple the dependency between the two functionality to facilitate upgrades and possibly rely on different vendors.
External links
- SS7 Overview Tekelek inc