A signaling gateway is a network component responsible for transferring signaling messages (i.e. information related to call establishment, billing, location, short messages, address conversion, and other services) between Common Channel Signaling (CCS) nodes that communicate using different protocols and transports. Transport conversion is often from SS7 to IP.
A SIGTRAN Signaling Gateway is a network component that performs packet level translation of signaling from common channel signaling (based upon SS7) to SIGTRAN signaling (based upon IP). The concept of the SIGTRAN signaling gateway was introduced in the IETF document: RFC 2719: Architectural Framework for Signaling Transport.
A signaling gateway can be implemented as an embedded component of some other network element, or can be provided as a stand-alone network element. For example: a signaling gateway is often part of a softswitch in modern VoIP deployments. The signaling gateway function can also be included within the larger operational domain of a Signal Transfer Point (STP).
Protocol conversion gateways can also convert from one network operational paradigm to another – for example, SIP to ISUP for call control, SIP to TCAP for address translation, or SIP to MAP for location or presence.
The Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, and terminating communication sessions that include voice, video and messaging applications. SIP is used in Internet telephony, in private IP telephone systems, as well as mobile phone calling over LTE (VoLTE).
Signalling System No. 7 (SS7) is a set of telephony signaling protocols developed in the 1970s, which is used to set up and tear down telephone calls in most parts of the world-wide public switched telephone network (PSTN). The protocol also performs number translation, local number portability, prepaid billing, Short Message Service (SMS), and other services.
In telecommunications, common-channel signaling (CCS), or common-channel interoffice signaling (CCIS), is the transmission of control information (signaling) via a separate channel than that used for the messages, The signaling channel usually controls multiple message channels.
A media gateway is a translation device or service that converts media streams between disparate telecommunications technologies such as POTS, SS7, Next Generation Networks or private branch exchange (PBX) systems. Media gateways enable multimedia communications across packet networks using transport protocols such as Asynchronous Transfer Mode (ATM) and Internet Protocol (IP).
The Message Transfer Part (MTP) is part of the Signaling System 7 (SS7) used for communication in Public Switched Telephone Networks. MTP is responsible for reliable, unduplicated and in-sequence transport of SS7 messages between communication partners.
A softswitch is a call-switching node in a telecommunications network, based not on the specialized switching hardware of the traditional telephone exchange, but implemented in software running on a general-purpose computing platform. Like its traditional counterparts it connects telephone calls between subscribers or other switching systems across a telecommunication network. Often a softswitch is implemented to switch calls using voice over IP (VoIP) technologies, but hybrid systems exist.
A global title (GT) is an address used in the SCCP protocol for routing signaling messages on telecommunications networks. In theory, a global title is a unique address which refers to only one destination, though in practice destinations can change over time.
A public-safety answering point (PSAP), sometimes called a public-safety access point, is a type of call center where the public's telephone calls for first responders are received and handled. It takes calls from any landline, mobile phone line, or VoIP line. It can also happen that when 112 is dialed in then a logic is implemented by mobile or network operators to route the call to the nearest police station. Such call centers exist in most countries to answer calls to an emergency telephone number. Trained telephone operators are also usually responsible for dispatching these emergency services. Most PSAPs are now capable of caller location for landline calls, and many can handle mobile phone locations as well, where the mobile phone company has a handset to location system. Some can also use voice broadcasting where outgoing voice mail can be sent to many phone numbers at once, in order to alert people to a local emergency such as a chemical spill.
The IP Multimedia Subsystem or IP Multimedia Core Network Subsystem (IMS) is a standardised architectural framework for delivering IP multimedia services. Historically, mobile phones have provided voice call services over a circuit-switched-style network, rather than strictly over an IP packet-switched network. Various voice over IP technologies are available on smartphones; IMS provides a standard protocol across vendors.
A session border controller (SBC) is a network element deployed to protect SIP based voice over Internet Protocol (VoIP) networks.
SIGTRAN is the name, derived from signaling transport, of the former Internet Task Force (I) working group that produced specifications for a family of protocols that provide reliable datagram service and user layer adaptations for Signaling System and ISDN communications protocols. The SIGTRAN protocols are an extension of the SS7 protocol family, and they support the same application and call management paradigms as SS7. However, the SIGTRAN protocols use an Internet Protocol (IP) transport called Stream Control Transmission Protocol (SCTP), instead of TCP or UDP. Indeed, the most significant protocol defined by the SIGTRAN group is SCTP, which is used to carry PSTN signaling over IP.
A back-to-back user agent (B2BUA) is a logical network element in Session Initiation Protocol (SIP) applications. SIP is a signaling protocol for managing multimedia Voice over Internet Protocol (VoIP) telephone calls. A back-to-back user agent operates between both end points of a communications session and divides the communication channel into two call legs, and mediates all SIP signaling between the endpoints of the session, from establishment to termination. As all control messages for each call flow through the B2BUA, a service provider may implement value-added features available during the call.
A Signal Transfer Point (STP) is a node in an SS7 network that routes signaling messages based on their destination point code in the SS7 network. It works as a router that relays SS7 messages between signaling end-points (SEPs) and other signaling transfer points (STPs). Typical SEPs include service switching points (SSPs) and service control points (SCPs). The STP is connected to adjacent SEPs and STPs via signaling links. Based on the address fields of the SS7 messages, the STP routes the messages to the appropriate outgoing signaling link. Edge STPs can also route based upon message body content using deep packet inspection techniques, and can provide address translations and screen content to limit the transfer of messages with dubious content or sent from unreliable sources. To meet stringent reliability requirements, STPs are typically provisioned in mated pairs.
An application-level gateway is a security component that augments a firewall or NAT employed in a mobile network. It allows customized NAT traversal filters to be plugged into the gateway to support address and port translation for certain application layer "control/data" protocols such as FTP, BitTorrent, SIP, RTSP, file transfer in IM applications. In order for these protocols to work through NAT or a firewall, either the application has to know about an address/port number combination that allows incoming packets, or the NAT has to monitor the control traffic and open up port mappings dynamically as required. Legitimate application data can thus be passed through the security checks of the firewall or NAT that would have otherwise restricted the traffic for not meeting its limited filter criteria.
H.323 is a recommendation from the ITU Telecommunication Standardization Sector (ITU-T) that defines the protocols to provide audio-visual communication sessions on any packet network. The H.323 standard addresses call signaling and control, multimedia transport and control, and bandwidth control for point-to-point and multi-point conferences.
Unstructured Supplementary Service Data, or USSD is a communication protocol used by GSM cellular telephones to communicate with the service provider's computers. A gateway is the collection of hardware and software required to interconnect two or more disparate networks, including performing protocol conversion.
HPE OpenCall is a range of network and telephony products offered by the "Communications & Media Solutions" branch of technology company HPE. It is most commonly described as a suite of software and hardware applications which allow implementation of common telecom operator services such as voicemail, sms, prepaid, billing, hlr, etc. It implements industry standard telecom protocols and standards such as SS7, ISUP, TCAP, SIP, MRCP, RTSP, and VoiceXML.
Edge STPs are networking hardware devices embedded with software that performs routing, signaling, firewall, and packet conversion functions. Their primary purpose is to unify networks that use various transports and signaling protocols – such as SS7, SIP, SIGTRAN, TDM, IP, etc. – into cohesive service environments. Unified environments are simpler for telecommunications companies to manage, and also enable them to cost-effectively transition to next-generation networks based on the Internet Protocol (IP).
The Media Gateway Control Protocol (MGCP) is a telecommunication protocol for signaling and call control in hybrid voice over IP (VoIP) and traditional telecommunication systems. It implements the media gateway control protocol architecture for controlling media gateways connected to the public switched telephone network (PSTN). The media gateways provide conversion of traditional electronic media to the Internet Protocol (IP) network. The protocol is a successor to the Simple Gateway Control Protocol (SGCP), which was developed by Bellcore and Cisco, and the Internet Protocol Device Control (IPDC).
Aculab is a privately held, UK-based limited company that was founded in 1978. It is a designer, developer and manufacturer that specialises in providing API-driven, enabling technology sub-systems for telecommunications related OEM products such as are used in fixed line PSTN, wireless and VoIP networks. Aculab's products are sold worldwide, primarily through direct sales and also via the reseller channel. Aculab's headquarters and R&D facilities are located in Milton Keynes, UK. It has a branch office in Norwood, Massachusetts, USA.
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