Intel SIU520 SS7 manual Communicating with Both Siua and Siub, GCTsetinstance, GCTgetinstance

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Building Fault-tolerant SS7 Systems Using the Intel® NetStructure™ SIU520 SS7 Signaling Gateway Application Note

Communicating with Both SIUA and SIUB

The user application exchanges information with the SIU via API messages (MSG). In a dual SIU environment, each time the user application sends a message to the SIU, this should be directed to either SIUA or SIUB using a library function GCT_set_instance. In the receive direction, the application can determine the SIU that sent a MSG using the library function GCT_get_instance. Function definitions may be found in the header

file sysgct.h.

GCT_set_instance

int GCT_set_instance(unsigned int

instance, HDR *h);

This function sets the destination instance number (SIU identity or siu_id) prior to sending a message and returns 0 on success, non-zero otherwise (currently no failure conditions are defined). SIUA is instance 0 and SIUB is instance 1, assigned by the siu_id parameter provided to the rsicmd utility. This function should be called immediately before GCT_send.

GCT_get_instance

unsigned int GCT_get_instance(HDR *h);

This function returns the instance number (SIU identity or siu_id) after receiving a message. The parameter h is a pointer to the HDR structure at the start of the received MSG. The returned value will be either 0 or 1. SIUA is instance 0 and SIUB is instance 1, as assigned by the siu_id parameter provided to the rsicmd utility.

Transferring Control of a Circuit Group between SIUs

Activating and Deactivating Circuit Groups

Configuration commands for all circuit groups must be present on both SIUs. At run time, the application running on each host should select which SIU is currently in con- trol of each group by “activating” and “deactivating” groups on a particular SIU.

Circuit groups are activated and deactivated using the API_MSG_COMMAND message (type 0x7f0f), with a cmd_type of 8 to activate a group and a cmd_type of 9 to deactivate a group. The format of this message is detailed in the Intel NetStructure SIU520 Developer’s Manual. This message should be issued with a request for a response (an acknowledgement); this will be returned to the requesting application with a status value of zero (indicating “success”) or non-zero values (indicat- ing “busy” or “failure”).

System Initialization

When the system starts-up, the host establishes communication with both SIUA and SIUB, either by using the rsicmd utility or by issuing RSI configuration API messages directly from within the application.

When the communication between the host and the SIU is established, the RSI task on the host issues an RSI_MSG_LINK_STATUS API message with a status value set to 1 (link to SIU recovered) to a destination task conc_id on the host (conc_id is set when the RSI link was started). This message will only be received by the application if the RSI link is configured with the conc_id set to the application’s module ID.

The ID field of this message is set to 0 to indicate SIUA and 1 to indicate SIUB. When the link to the SIU that normally controls a circuit group (the primary SIU) becomes active, the application should issue an activate group command to that SIU, specifying that circuit group (using its group ID). The SIU processes API commands sequentially and the application must wait for an acknowledgement of this command before proceeding. An acknowledgement that indicates “busy” should cause the application to re-attempt the activate command.

The application should wait for a period of time sufficient to establish communication to the preferred SIU before deciding that the preferred unit is not available and activating circuit groups on the non-preferred or secondary SIU.

Once the acknowledgement of the activation of a circuit group is received, the circuits should be reset to force the circuits into a known, idle state. This is achieved using the Circuit Group Status Control (CGSC) Request API message, detailed in the appropriate Programmer’s Manual. The circuit reset is acknowledged by the terminating exchange; this acknowledgement is passed to the user application as a circuit group status confirmation API message. On receipt of this, the application may commence using the associated circuits for calls.

Failure Detection

The event that triggers the application to transfer circuit groups from one SIU to another is loss of communication between the application and the SIU.

When the failure occurs, the RSI task on the affected host detects the loss of communication and issues an RSI_MSG_LINK_STATUS API message with a status value set to 2 (link to SIU lost) to a destination task

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Contents Intel Communications Application NoteTable of Contents Table of Figures Abstract Circuit-switched API Operation SIUTransaction-based API Operation Management InterfaceFailure of SS7 Links SIU Connected to Adjacent Node with Two Links in Link SetFailure of Routes LinkFailure of Power Supply Failure of Signaling Interface UnitConnection to a Single Adjacent Signaling Point Routing Architectures of a Dual-resilient SIU SystemConnection to an Adjacent Mated STP Pair Compares the advantages and disadvantages of these methods Dual SIU Architecture for Circuit-Switched Applications SS7MTP1-3 Circuit Group Active Inactive MTP1-3 Dual SIU Architecture for Transaction-based Applications Siua SiubSS7 Failure of IP Subnetwork Failure of ApplicationHost SIU520Hardware Requirements Inter-SIU Link over Crossed E-1/T-1 CableSystem Configuration Changes to the config.txt Parameter FileConfiguring the Inter-SIU Link Routing Configuration Circuit Group ConfigurationExample Configuration Connecting a Host to Two SIUs For SiuaFor Siub Communicating with Both Siua and Siub GCTsetinstanceGCTgetinstance Transferring Control of a Circuit Group between SIUsTransferring the Circuit Group Re-synchronization of Circuit State InformationRecovery of the Failed Unit Transferring Control BackCircuit Group Conflict How can I tell if an SIU fails? If an SIU fails do I need to take any action?What happens if an inter-SIU SS7 link fails? What happens if the Ethernet interfaces fail on an SIU?Route Ten Parsippany, NJ Phone

SIU520 SS7 specifications

The Intel SIU520 SS7 is a significant advancement in the realm of telecommunications, specifically designed for seamless signaling in a wide array of telecommunication infrastructures. As a part of Intel's pioneering suite of products, the SIU520 plays a critical role in managing signaling for telephony systems that require efficient handling of SS7 protocols.

One of the main features of the SIU520 is its support for the SS7 signaling protocol, which is pivotal for the establishment and management of telephone calls over traditional circuit-switched networks. With its robust design, the SIU520 ensures reliability in signaling, contributing to the reduction of call set-up times and the minimization of errors, thus enhancing the overall quality of communication services.

The SIU520 incorporates advanced technologies such as high-speed data processing capabilities, allowing it to handle multiple signaling messages concurrently. This is particularly important in environments with high call volumes, where efficient processing can significantly affect the performance of telecommunication services. Furthermore, the architecture of the SIU520 is designed for scalability, enabling easy integration into existing infrastructures while accommodating future expansions as demand increases.

Another characteristic that sets the SIU520 apart is its support for various signaling types beyond standard SS7, including ISDN and SIP. This makes it a versatile tool for service providers aiming to offer diverse services, such as voice, video, and data communications. The SIU520 is also designed with a focus on interoperability, which ensures that it can effectively communicate with equipment from different manufacturers, thus providing flexibility in deployment.

In terms of security features, the SIU520 is architected to withstand common threats in the communication landscape. It employs encryption and authentication protocols to safeguard signaling traffic, ensuring that sensitive information remains protected during transmission.

In summary, the Intel SIU520 SS7 represents a robust and flexible signaling solution crucial for modern telecommunications. With its support for multiple protocols, high processing speeds, scalability, and secure communication capabilities, it stands as a testament to Intel's commitment to advancing telecommunication technologies and enhancing the efficiency and reliability of communication networks worldwide.
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