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After 1999: The role of testing and diagnostic equipment in SS7 networks.


When clocks around the world begin to mark the passing of time in the new millennium, Signaling System 7 (SS7) will retain its importance as the command-and-control signaling technology required for both voice-centric (PSTN) and data-centric (especially Internet protocol) networks. Because of its ability to support the interworking of these two network types, SS7 will also provide the technological foundation for the growing number of hybrid networks that are making convergence a buzzword in the telecommunications industry. We already rely on SS7 to enable basic call setup and teardown, as well as intelligent network (IN) services, such as toll-free calling, number portability, and calling-name delivery.

To support the new century's rapidly growing voice-over-Internet protocol (VoIP) networks and next-generation custom-calling services, carriers will rely on SS7 signaling even more--with demand for its IN functions coming from both sides of the circuit-data "divide." On one side, traditional public switched telephone networks (PSTNs) will incorporate packet-switched technology to obtain tremendous operational and cost efficiencies. On the other side, next-generation Internet protocol (IP) networks will seek to provide the latest IN services while interfacing with legacy networks. As a result, they, too, will need SS7 to provide the technological glue in the network mix.

With so many carriers rushing to provide both current and next-generation services on hybrid networks with heterogeneous equipment, testing will play a pivotal role. Consequently, providers of testing and diagnostic equipment will be called upon to meet the needs of the following three purchasers of testing equipment and services:

1. Equipment manufacturers who require SS7 testing equipment to design their products;

2. Equipment purchasers (typically network operators) who must test the equipment provided by competing manufacturers before making a purchase decision for their networks; and

3. Network operators who rely on testing and diagnostic equipment to maintain, monitor, and control their SS7 networks to prevent the unthinkable--a network going out of service.

At the same time, the purchasers of testing and diagnostic equipment will be rating their suppliers by the way they answer the following questions:

* Given the nature of the worldwide telecommunications market, is your testing equipment protocol-independent?

* Does your testing equipment support protocol conversions?

* Does your testing equipment identify the critical elements and network functions that are mandatory for successful network operation?

* Have you incorporated a thorough understanding of SS7 technology, as well as wireless, wire-line, and converged networks, into your testing and diagnostic equipment?


Manufacturers of IP and telephony equipment rely on SS7 testing and diagnostic equipment to design their products. They recognize the importance of building a product right the first time--testing its functionality within the safe environment of the R&D laboratory before installing it in a live network. In general, these network equipment manufacturers fall into two camps, a situation that mirrors the "divide" between PSTN and data networks. On one hand, data-communications product manufacturers are trying to break into the telephony equipment market by adding voice and IN services to their original array of IP network devices. They will have a tough time trying to outcompete the tried-and-true telephony manufacturers, who have longstanding reputations for product reliability and robust performance. On the other hand--trying to prevent the success of the next-generation data communications manufacturers--are the traditional telephony manufacturers. They correctly perceive the threat to their existing market dominance.

Both types of manufacturers will utilize testing and diagnostic equipment as they create products, such as media gateway controllers, signal control points (SCPs), media gateways, voice gateways, access products, dial-offload solution products, signaling gateways, signal transfer points (STPs), and intelligent SCPs. As they develop these products, their testing and diagnostic programs will focus on performing the following tests in the safe environment of a lab before a product goes to market:

* Compliance with standards;

* Conformance with each purchaser's unique network requirements, since most carriers have proprietary overlays;

* Interoperability with other network equipment since most networks are heterogeneous;

* Load and stress testing, which requires simulation of call volume so that network operators can properly size networks by obtaining information about the maximum call volume that can be supported; and

* Simulation testing for every situation likely to occur in a live network (functionality).


Network purchasers (typically network operators) are adopting IP technology primarily for economic reasons. For example, they can reduce expenditures for central-office (CO) switching to a tiny fraction by choosing IP instead of circuit-switched technology. When they begin to evaluate the array of testing and diagnostic equipment that is available, however, they need the assurance that their purchase will work with SS7 technology so that they can address important trends such as converging networks. For these purchasers, the key decision point is finding a product that "fits" into their network--in terms of industry standards, proprietary overlays, call volume, and interoperability. More important than all of the bells and whistles that new products offer is their ability to seamlessly function within a network and handle SS7 technology. Consequently, purchasers depend on testing and diagnostic equipment to identify the equipment that will provide optimum service for their networks.


Network operators utilize testing and diagnostic equipment to maintain, monitor, and control their SS7 networks. Their objective? It can be summed up in two concepts: (1) reliability and (2) centralized control.

1. Reliability is also known as "the confidence factor." When an IP network hosts emergency telephone calls, such as 911 services, these calls simply must be completed. There's no alternative. In the same vein, since most CLECs (competetive local exchange carriers) and ISPs (Internet service providers) are funded by venture capital, an event such as a network crash that takes out an entire service area can have devastating financial ramifications. Investment capital is liquid; if the price of a stock falls precipitously as a result of a network failure, funds evaporate--sometimes taking the service provider right along with them. It is no surprise that network operators look for proactive diagnostic equipment so that the operations center can be alerted to potential problems before subscribers notice them. To meet the demand for reliability, operators evaluate surveillance equipment in terms of its ability to prevent problems by sifting through pertinent messages and spotting SS7 links that are about to fail.

2. Network operators seek centralized control to gain competitive advantages. If their monitoring equipment is centralized and efficient, it allows them to run a network from fewer locations and with fewer human resources. This frees up the time of their valuable engineers so that they can perform strategic functions instead of reacting to an endless series of crises. Furthermore, if the testing equipment is easy to use and flexible, these engineers can use it to develop and schedule customized tests to monitor the network for optimum performance and reliability. Finally, when there is a problem, centralized control helps engineers to quickly arrive at a solution or make necessary changes and network additions with minimal effort.

As we move toward network convergence and service providers try to incorporate new technologies to obtain cost savings and new services, they will not sacrifice reliability. In the new millennium, CLECs and ISPs will continue to understand that reliability is the lynchpin of their networks and that without it, they will not be successful.

Circle 272 for more information from Tekelec

Lewis, product manager, and Grant, assistant vice president of marketing, are employees of the Intelligent Network Diagnostic Division of Tekelec, Morrisville, N.C.
COPYRIGHT 1999 Nelson Publishing
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1999 Gale, Cengage Learning. All rights reserved.

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Title Annotation:Signaling System 7
Comment:Signaling System 7 (SS7) is the command-and-control signaling technology used for voice-centric (public switched telephone networks, or PSTN) and data-centric (IP) networks.
Author:Lewis, John; Grant, Cory
Publication:Communications News
Article Type:Buyers Guide
Geographic Code:1USA
Date:Aug 1, 1999
Previous Article:Test Equipment Buyers' Guide.
Next Article:Latest test products.

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