How do you implement SS7 interworking and interoperability with other networks and technologies?

1 Understand the SS7 architecture and functions

SS7 consists of three main components: signaling points, signaling links, and signaling networks. Signaling points are nodes that exchange messages, such as switches, databases, or gateways. Signaling links are the physical or logical connections between signaling points, such as E1, T1, IP, or ATM. Signaling networks are the hierarchical structures that define how signaling points are grouped and routed, such as A, B, C, or D networks. Each signaling point has a unique address, called a point code, that identifies its location and function in the network.

2 Choose the appropriate SS7 interworking solution

In order to achieve SS7 interworking and interoperability, there are various solutions available. Gateway screening is a basic solution that involves filtering and modifying the SS7 messages at the border of two networks, such as adding or removing parameters, changing point codes, or translating protocols. This can be done using a dedicated device or a network element. Gateway conversion is a more advanced solution that involves converting the SS7 messages into another format or protocol, such as SIP, ISUP, or MAP. This can be done using a specialized device or a network element. Lastly, gateway emulation is a complex solution that involves emulating the SS7 functionality and behavior of one network in another network. This can be done by a sophisticated device or by a network element.

3 Follow the SS7 interworking standards and guidelines

SS7 interworking and interoperability are not only technical, but also regulatory and commercial issues. As such, it is important to follow the standards and guidelines that govern SS7 interworking and interoperability among different networks and technologies. The International Telecommunication Union - Telecommunication Standardization Sector (ITU-T) is the global body responsible for developing and maintaining the SS7 standards and recommendations, such as Q.700-series, Q.800-series, and Q.900-series. The European Telecommunications Standards Institute (ETSI) is the regional body that develops and harmonizes the SS7 standards and specifications for Europe, such as ETS 300-series and ETSI EN 301-series. As for North America, the American National Standards Institute (ANSI) develops and coordinates the SS7 standards and specifications, such as T1.110-series and T1.111-series. Finally, the 3rd Generation Partnership Project (3GPP) is the global body responsible for developing and maintaining the SS7 standards and specifications for mobile networks, such as TS 23-series and TS 29-series.

4 Test and monitor the SS7 interworking performance and quality

Testing and monitoring SS7 interworking and interoperability are essential to ensure the performance and quality of the voice and data communication across different networks and technologies. Signaling load, signaling delay, and signaling error must all be monitored. Signaling load measures the amount of signaling traffic that flows through the signaling links and networks, while signaling delay measures the time it takes for a signaling message to travel from one point to another. It is also important to test for any abnormal or unexpected conditions in the signaling message or process, such as missing, corrupted, or rejected messages. Monitoring these aspects is necessary to ensure that capacity and reliability are not exceeded, quality of service is maintained, functionality and security are not impacted, and latency and jitter are minimized.

5 Implement the SS7 interworking security and protection

SS7 interworking and interoperability can open the door to fraud, spoofing, interception, or denial of service. To protect the confidentiality, integrity, and availability of voice and data communication across different networks and technologies, it is necessary to implement SS7 interworking security and protection measures. Authentication verifies the identity and legitimacy of signaling points and messages, while encryption transforms signaling messages into a secret code that can only be deciphered by authorized parties. Firewall devices or software control and filter incoming and outgoing signaling traffic between networks, while intrusion detection systems or tools monitor and analyze the signaling traffic for suspicious or malicious activity.