Introduction

Since being standardized by the ITU in the early 1980's, SS7 (Signaling System 7) has become the principle protocol for core telephony network communications. SS7 is an out-of-band protocol that operates on a separate network from the voice or other bearer traffic. Central Office Switches, Short Message Service Centers (SMSC), Home Location Registers (HLR), Service Control Points (SCP), as well as a number of other core telephony network systems communicate with each other using SS7. SS7 is used to set up calls, exchange location information, and provide routing instructions as well as a host of other purposes that are essential to the operation of telephony networks throughout the world. <br>

 

Challenges

Typically, core network telephony systems that require access to the SS7 network incorporate one or many SS7 interfaces. The SS7 interface hardware and software can either be incorporated into the design of the system or can be integrated into computing platforms by using SS7 software and specially designed interface boards that are plugged into the bus of the computing platform. The tight integration of SS7 into the system poses some unique challenges, such as:

• The system designers need to have intimate knowledge of SS7. They need to "take ownership" of the SS7 interface rather than focusing on their value-add
• Each system with integrated SS7 will need to be certified in all of the networks where it will be deployed
• The use of specialized interface boards limits the types of computer platforms that can be utilized as the foundation of the system. Often these computing platforms are more expensive due to the number of slots required for the interface boards To overcome these challenges different approaches have been attempted with varying degrees of success:
• SS7 on a Board - this solution separates the SS7 interface from the system but still requires that the board itself be accommodated in the same equipment rack. In addition, often the interface provided to access the SS7 board is proprietary
• Outboard SS7-this solution provides the SS7 interface in a separate box and may offer a proprietary interface or a standards-based interface. Often, these solutions lack the flexibility to allow the system to be addressed directly from the network via a network-visible SS7 point code, and requires the system to adopt the SS7 point code of the Outboard box
• SS7 over IP - in an effort to avoid incorporating SS7 hardware into the system, some designers have chosen to only support SS7 over IP in their systems. This approach utilizes the Ethernet interfaces typically incorporated in the computing platform but does not address deployment scenarios that require traditional SS7 interconnect

 

Solution

An ideal solution to the signaling requirements in the industry is the introduction of a Signaling Hub. The Signaling Hub offers the ability to isolate and centralize the interface to the network, offering the following advantages to the service provider (SP) and the network equipment provider (NEP):

• Extracts the SS7 interfaces from the system and allows the NEP to focus on their core competencies and the value that they bring to the overall solution, resulting in a lower overall system cost and earlier time to market
• Centralizing the interface to the core network in the Signaling Hub enables the SP or network operator to certify the Signaling Hub's network interface one time. This allows additional services and systems to plug in using standardized protocols without the need to re-certify the core network interface
• Extracting the core network interface from the system enables lower cost computer platforms to be selected for the systems. Since only an Ethernet interface is required to interface to the Signaling Hub, more expensivespecialized SS7 interface boards that consume bus slots are not required

 

Ulticom nSignia eSTP

Ulticom's nSignia^® eSTP offers a number of features that make it an ideal Signaling Hub:

• Highly available architecture composed of multiple computing platforms maintaining a single point code and network appearance independent of the number of signaling links deployed
• Support for standard IETF M3UA, SUA, and M2PA specifications allowing systems to interface to nSignia eSTP in a manner that is optimal for the system
• Multiple routing scenarios are supported by nSignia eSTP, allowing systems behind the Signaling Hub to be addressed from the network as a distinct point code (utilizing nSignia eSTP's STP functions), or as a segment of traffic of nSignia eSTP's point code (utilizing Subsystem or CIC routing keys)

 

Key Business Benefits

• Reduces the costs of systems based on the ability to use lower cost computing platforms with minimal bus slots combined with the extraction of the signaling interfaces
• Provides earlier time to market for service based on the ability to leverage the Signaling Hub's pre-certification with the network
• Enables rack and stack architectures based on IT technology enabling systems to be added, equipment to be replaced, and capacity increased without network or customer impact
• Turnkey delivery of Ulticom's nSignia eSTP, together with world-class support, allows the service provider and the network equipment provider to concentrate their attention on their core competencies