Productos

Aculab offers SS7 support as part of its extensive range of signalling protocols, any of which run interchangeably on the proven range of digital network access and Prosody media processing platforms in PCI, PCIe and cPCI format. The SS7 protocol software allows users to connect directly to an SS7 network and the software is available under a cost free licence, like our other digital network access protocols, via the Aculab installation tool (AIT).

Applications
The implementation of Aculab's SS7 is intended to assist developers and integrators designing value-added solutions for public telephony networks. These may range from complex protocol conversion solutions, to network-based messaging applications, prepaid calling card platforms and other revenue generating services. Additionally, the SS7 signalling monitor is ideal for lawful interception (LI) mediation and delivery platforms.

Many applications also require media processing resources, such as record, playback, DTMF handling and echo cancellation, which are available for use with Aculab's Prosody platforms to deliver powerful computer-based solutions.

All Prosody and E1/T1 hardware platforms support the complete range of digital network access protocols, including SS7, with an optional or fitted primary rate trunk interface. For GSM MAP or ANSI 41 D applications like SMS messaging, when signalling traffic can be intense, Prosody X or an E1/T1 cPCI card fitted with a PMXC module is ideal, with up to 128 signalling links providing increased throughput.

Protocol support
Aculab's SS7 product supports MTP, ISUP, SCCP and TCAP protocols. The availability of the TCAP and SCCP allows multiple network-based application subsystems to be addressed explicitly, enabling advanced access database query services and global title translation.

At the API, on a per call basis, the user has access to and control of many of the ISUP and TCAP protocol parameters. The API also provides a lower level of access to ISUP parameters. For users requiring more complex control, direct access to raw data ISUP parameters, through ‘flexible ISUP' extensions to the generic call control API, is provided.

The product presents a standard TCAP API to developers to support both TCAP structured and unstructured dialogues, as required by INAP or GSM MAP applications and as described in ITU-T Q.771 TCAP. It is the same API wherever TCAP is used on any card from Aculab's portfolio offering trunk connectivity via PMXC/PM digital network access. The TCAP API includes ASN.1 codec 'helper' functions, which obviate the need for expensive, 3rd party compilers or APIs.

Multi-threaded applications
The Aculab TCAP API includes supporting software that enables easy construction of multi-threaded applications, with mechanisms that automatically manage thread pools and route TCAP traffic to individual threads for processing. In addition, many of the system facilities required for a multi-threaded application that are normally operating system specific, such as threads libraries, are presented in an operating system independent interface. This makes for easier portability of applications between platforms.

Capacities
The software supports an unrestricted number ISUP and TCAP hosts, including an unrestricted number of E1/T1 bearer circuits and up to 128 signalling links - see table for details.

Connection to the network is supported using any of the digital network line interfaces (trunks), which carry user-defined 64kbit/s timeslots for signalling links, and that may reside on more than one Aculab card. Timeslots within the trunks on Aculab cards that are not used for signalling are available as voice/data bearer circuits, thereby leading to maximum cost efficiency.

Prosody X and E1/T1 cPCI card variants using PMXC modules support up to 128 signalling links that may be freely allocated over the trunks on the card.

Easier maintenance
An SS7 maintenance tool facilitates actions such as manually installing and uninstalling drivers, starting and configuring the protocol stack, and obtaining diagnostic information to aid troubleshooting. There are also options to aid conformance testing, such as traffic generation and manipulation.

Signalling scalability and resilience
When multiple signalling links are configured together in a single link set, the software will load share traffic between them, and automatically change over when individual links become unavailable/available, providing essential resilience.

Signalling links can operate in fully associated signalling mode (F-links) or quasi-associated mode and form one or more link sets. Because of this, the product can be connected to one or more service switching points (SSPs) or one or more signal transfer points (STPs) in the network. Resilience is achieved in that there is no reliance on a single delivery trunk from the network.

Signalling links within the same link set can reside on more than one Aculab card within a system, ensuring that a single card level failure does not cause a loss of signalling connectivity to the SS7 network. For added reliability, a dual resilient MTP3 allows a ‘twin' configuration, with the signalling links split between cards in two chassis, appearing as a single network node. A single link set can be split between the two MTP3 systems or separate link sets used to connect each system to a different STP.

In addition, for large systems, the ISUP and TCAP architecure allows cards providing bearer channel terminations, and ISUP and TCAP applications, to be installed or implemented in multiple, distributed chassis/nodes, each sharing a single point code. This enables excellent scalability and application resilience, because problems with a single ISUP/TCAP node won't affect the operation of the rest of the system.

Specification detail
The ISUP products are based on ITU-T International ISUP (compatible with most national variants of ITU-T ISUP) and offer support for other national and international variants, including ANSI and China. Similarly TCAP, SCCP, MTP3 and MTP2 support conforms to the relevant ITU-T, ANSI and China protocols. The software also supports the combination of ANSI TCAP with ITU SCCP (and vice versa), as required in some markets. An SS7 developer's guide, which is recommended reading, is available from the technical documents pages.