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The Signalling System 7 (SS7) stack plays a pivotal role in the telecommunications industry, enabling the efficient exchange of signalling messages between network elements. As a cornerstone of modern telecommunication networks, the SS7 stack encompasses various components, including the Mobile Application Part (MAP), the CAMEL Application Part (CAP), and more. In this blog, we will delve into the different components of the SS7 stack, exploring their individual use cases and contributions to the seamless functioning of telecommunication networks

SS7 Stack Overview

The SS7 stack is a collection of protocols and network elements that facilitate the exchange of signalling messages between telecommunication network components. These messages carry critical information, enabling essential functions such as call setup, routing, billing, and more. By separating signalling from the voice and data channels, the SS7 stack optimizes network performance and enables enhanced services

Mobile Application Part (MAP)

One of the key components of the SS7 stack is the Mobile Application Part (MAP). MAP provides signalling capabilities for various mobile network functions, including mobility management, authentication, location services, and SMS. MAP ensures the smooth operation of services like roaming, call routing, and subscriber management across different network operators and technologies.

CAMEL Application Part (CAP)

The CAMEL Application Part (CAP) is another vital component of the SS7 stack. CAP enables intelligent network features and services, allowing operators to offer advanced functionality beyond traditional voice and messaging services. CAP supports services like prepaid calling, call forwarding, and call screening, providing flexible and personalised solutions to subscribers.

ISDN User Part (ISUP)

The ISDN User Part (ISUP) is responsible for call setup and teardown in circuit-switched networks, handling signalling between switches during voice and video calls. ISUP ensures that calls are routed correctly, manages call progress tones, and handles call-related events such as call waiting and call holding. It is a crucial component for maintaining the integrity and reliability of voice communications.

Latest Advancements in SS7

In recent years, the SS7 stack has undergone significant advancements to address evolving communication needs and enhance network security. One notable advancement is the implementation of SIGTRAN (Signalling Transport), which enables the transport of SS7 messages over IP networks. This shift from traditional circuit-switched networks to IP-based networks has increased flexibility, scalability, and cost-effectiveness in signalling transmission.

Additionally, Diameter, a protocol that provides enhanced signaling capabilities, has emerged as a potential successor to SS7. With its improved security features and support for more diverse services, Diameter has gained prominence in next-generation networks, such as 4G and 5G.

Furthermore, the industry has recognized the importance of strengthening SS7 security due to the emergence of vulnerabilities that can be exploited for unauthorized access and fraud. Efforts are underway to implement security measures such as firewalls, signalling firewalls, and intrusion detection systems to safeguard the SS7 infrastructure from potential threats.

SS7 Libraries and Tools

Several providers offer SS7 libraries and tools that simplify the development and integration of SS7 functionality into telecom applications. Here are two notable providers known for their Java libraries and developer-friendly offerings:


Mobicents, now known as Restcomm, is a well-known provider of open-source telecommunication solutions. They offer a range of SS7-related tools and libraries that can be easily onboarded by developers. One of their prominent offerings is the Mobicents jSS7 library, which is a pure Java implementation of the SS7 protocol stack. The jSS7 library provides a comprehensive set of APIs, enabling developers to build SS7-based applications and services with ease. Mobicents also provides additional tools and utilities that assist in testing and debugging SS7 functionality.


Dialogic is a leading provider of communication and networking technologies, including SS7 solutions. They offer SS7 software development kits (SDKs) that provide developers with powerful tools and libraries to integrate SS7 functionality into their applications. The Dialogic SDKs support various programming languages, including Java, making it convenient for Java developers to leverage SS7 capabilities. These SDKs provide extensive documentation, sample code, and support resources to aid developers in efficiently utilizing SS7 features.

It’s worth noting that these are just a couple of examples, and there are other providers in the market offering SS7 libraries and tools. When considering a specific provider, it’s important to evaluate factors such as the level of support, documentation, community resources, and compatibility with your specific development environment and requirements.

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