Q Signaling


Q Signaling, also known as QSIG, is a telecommunication protocol used for signaling on a Private Integrated Services Network (PISN). It’s primarily used for establishing, managing and terminating the network connections on an Integrated Services Digital Network (ISDN). This protocol allows various network services to interact and communicate through PBX systems.


The phonetics of the keyword “Q Signaling” would be: cue sigh-nuh-ling.

Key Takeaways

Main Takeaways about Q Signaling:

  1. Q signaling, often written as QSIG, is a protocol for Integrated Services Digital Network (ISDN) that provides a robust framework for network signaling. It is primarily used for signaling between private branch exchanges (PBXs) in a private integrated services network (ISDN).
  2. QSIG is based on the Q.931 protocol which allows for clear channel capability, making it more flexible and capable of handling a wider variety of services compared to other signaling protocols. It emphasizes on interoperability between different manufacturers’ devices.
  3. QSIG supports various services, including basic call handling, call diversion and forwarding, call transfer, and call completion. It also provides supplementary services, like caller ID, and advanced features for corporate telecommunication networks, which increases its usability and effectiveness for businesses.


Q Signaling, also known as QSIG, is a significant term in telecommunications, particularly in the realm of digital networking. Its importance lies in its use in the integration of Private Branch Exchange (PBX) systems on Integrated Services Digital Network (ISDN). In technical terms, Q Signaling serves as a protocol that allows various network services (like caller ID, call forwarding, and call transfer) to be used across a network that connects multiple PBX systems. It essentially enhances telecommunication flexibility and effectiveness in large enterprises by allowing the seamless operation of features across different locations. Without QSIG, operating an integrated, feature-rich telecommunication network would be considerably more challenging.


Q Signaling, often referred to as QSIG, is a major component in integrated telecommunications networks, focusing mainly on private networks rather than public ones. The primary purpose of Q Signaling is to enable PBX (Private Branch Exchange) systems – the telephone exchanges for a particular business or office – from different manufacturers to communicate with each other. By providing a standardized protocol, QSIG ensures smooth intercommunication between devices, ensuring effective and efficient networking.The utilization of Q Signaling goes beyond just PBX systems. It supports a wide range of services including basic call setup and teardown, call diversion and transfer, caller identification, and messaging, amongst others. In the process, Q Signaling significantly enhances the ability of the network to offer value-added services. It allows interconnectivity and interoperability between various equipment, ensuring optimal usage of resources and sophisticated network management. This makes it a fundamental aspect of contemporary network technology.


Q signaling (or QSIG) is a protocol for Integrated Services Digital Network (ISDN) communication that is utilized worldwide. The protocol is used for signaling, specifically for establishing, maintaining, and ending the call sessions. Here are three real-world examples:1. Business Telephone Systems: Q signaling is extensively used in the business communication systems where there is requirement for communication between Private Branch Exchange (PBX) systems, which can ensure compatibility of communication protocols. Example: PBX systems used by larger businesses which have various departments located in different office buildings. 2. Home Networking: QSIG is also used in home networking scenarios where ISDN lines are in use. They can be utilized to make effective communication within a small network of home-based devices. Example: A small home office scenario where different computers are networked to share a single ISDN line. 3. Broadband ISDN: B-ISDN, which transfers voice and data over the same line, also uses Q signaling for establishing and managing connections. Example: Fiber-optic internet service provided by ISPs. They require QSIG for setting up and managing connections, allowing for voice calls and data transfer simultaneously.

Frequently Asked Questions(FAQ)

**Q: What is Q Signaling?** A: Q Signaling, also known as QSIG, is an ISDN signaling protocol, standardized by the ECMA and used widely in corporate telephony networks. Its primary function is to facilitate communication across Private Integrated Services Network Exchange (PINX) in corporate telephony networks.**Q: Is Q Signaling specific to any particular geographic location?** A: No, it’s a global standard in use in many countries and is not geographically exclusive.**Q: Where is Q Signaling commonly used?**A: Q Signaling is used in numerous corporate telephony networks to facilitate communication across different equipments like PABXs, Routers, and other network devices.**Q: Are there different versions of the Q Signaling protocol?** A: Yes, there are different versions of the protocol, the most prominent being the Basic Call, Call Transfer, Path Replacement, Call Diversion, and Call Completion, among others.**Q: How does Q Signaling work?** A: Q Signaling works by facilitating communication across a Private Integrated Services Network Exchange (PINX). It accomplishes this by using various protocols that work together to ensure seamless communication.**Q: What is the relationship between ISDN and QSIG?**A: ISDN (Integrated Services Digital Network) is the set of communication standards for digital telephone connections which carry voice, video, and data with a high level of quality. QSIG is a protocol for ISDN connections, aiding in the establishment, control, and termination of these connections in Private Networks.**Q: Can QSIG be used in public networks?**A: QSIG is primarily designed for use in private networks. However, it allows interconnectivity with public networks, but it’s functionality may be limited compared to usage within private networks.**Q: What benefits does Q Signaling offer in corporate telephony networks?** A: Q Signaling offers compatibility across different manufacturers’ equipment, enhanced features like call forwarding and call transfer, and increased efficiency and quality in voice, video, and data transmission in corporate telephony networks. **Q: Are there alternatives to Q Signaling?**A: Yes, there are other signaling systems like DSS1 and Q.931 utilized for different purposes, but QSIG stands out for its diverse application in private corporate telephony networks.

Related Tech Terms

  • Signaling System 7 (SS7)
  • Protocol Stack
  • Digital Signaling
  • Integrated Services Digital Network (ISDN)
  • Channel-Associated Signaling (CAS)

Sources for More Information


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