Download VOIP Overview - Welcome to Coast Data Systems Limited

By Yolanda Greene,2014-11-10 19:52
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Download VOIP Overview - Welcome to Coast Data Systems Limited

VoIP (Voice over IP) - an overview

    With the rapid changes taking place in communications technology today, decision-makers face both compelling opportunities and potentially costly pitfalls. "Convergence" - whereby voice, fax, data and multimedia traffic are transmitted over a single multipurpose network (IP) - is a particularly delicate issue. The business advantages of combining a company's various types of communications over a common infrastructure are appealing.

    1) Lower recurring transmission charges

    By directing voice calls over the corporate data network, rather than through a carrier, companies can significantly reduce their monthly phone bills. These savings are obviously dependent on several factors, including the volume of intracompany calls and the distances between company offices. Companies with overseas offices, can experience the greatest savings, since they can eliminate a great deal of international long-distance charges. These charges are often particularly high when the call originates in a foreign country that still has a monopolistic telecom market.

    2) Reduced long-term network ownership costs

    In addition to reducing a company's monthly phone bills, a converged network architecture also reduces the ongoing costs of owning two separate networks - one for voice and one for data. These costs include the need to buy two separate sets of equipment, the staff time dedicated to the "care and feeding" of that equipment, the licensing of any software relating to the management of that equipment, and the monitoring of traffic on the two networks.

    3) The ability to deploy powerful new integrated voice-and-data applications Of course, businesses don't exist just to save money. They exist to make money, gain marketshare, and serve customers. That's why the most compelling aspect of converged voice/data networking may well be the new generation of applications it enables. These applications include Web-enabled call centers, unified messaging and real-time collaboration

    Risk Factors in Voice-over-IP Implementation

    Any potential business gain comes with a variety of potential business risks. Voice-over-IP is no exception. Market research indicates that the following risks are of greatest concern

    1) Loss of voice quality

    Any deterioration in that quality is perceived as very disruptive to the normal way of doing business - and users won't tolerate it.

    2) Loss of reliability

    Immediate and uninterrupted access to others over the phone is such an essential aspect of conducting business that few executives want to put voice communications at risk, regardless of how attractive the potential savings may be. Technologists and business people both know from experience that data networks are not yet as reliable as voice networks.

    3) Being prematurely "locked-in" to a given vendor's architecture

    The pace of change in computing and communications technology today makes vendor "lock-in" a major concern for any potential buyer. Not just in terms that something better will come along shortly after a commitment has been made, but more importantly that the lock-in extends far beyond the VOIP solution itself.

    Voice-over-IP Implementation Options

    While the VoIP market continues to evolve, the current universe of VoIP implementation options can be segmented into four broad categories. Each of these has its own advantages and disadvantages: PBX-based gateways

    The leading manufacturers of PBX equipment are all introducing their own solutions to the VoIP challenge.The downside is that these vendors have minimal experience in IP-centric data networking. However, the biggest drawback to the PBX-based approach is that this class of solution is tied so directly to highly proprietary PBX platforms. The leading PBX vendors have no demonstrable track record in either defining or adopting the types of open technical standards that have accelerated adoption of the Internet over the past decade.

    Router-based gateways

    Manufacturers of routers and other data networking hardware are also attacking the VoIP market.

    Unfortunately router vendors' unfamiliarity with voice technology and call management continues to hamper their ability to deliver corporate-class telephony solutions. More and more, they are steering their customers to so-called "end-to-end" solutions - which is really a code-phrase for requiring a single manufacturer's equipment across the edge, access and core strata of the network. This, again, represents the type of lock-in that most technology managers would prefer to avoid at this early stage of their VoIP plans.

    PC-based gateways

    Several vendors are bringing stand-alone gateways to market. These products offer a router- and PBX-independent solution, since they are not tied to a particular manufacturer's platform. However, stand-alone gateways are also typically based on a PC platform, which calls into question their inherent reliability.

    Intelligent, multi-path switching gateways

A fourth alternative to the above categories has recently appeared on the VoIP scene: the multi-path switch. These devices are specifically designed to address the issues unanswered by the product categories described above - including voice quality, network reliability, and vendor independence.

    The multi-path voice/data switch

    A multi-path voice/data switch sits between the corporate PBX and both the PSTN and the corporate IP data network. Its most prominent distinguishing characteristic is its ability to continuously monitor the condition of the data network, and to route voice traffic accordingly. This intelligent switching capability is the key to its value for safe, controlled migration to VoIP. If conditions on the corporate network are sufficient to support the required level of voice quality, the gateway switches voice traffic to the appropriate router. If conditions on the corporate network deteriorate for any reason, the switch automatically and transparently re-directs voice traffic over the public switched network. Intelligent multi-path switching addresses the foremost concerns of both business and technology managers who are considering a first-stage implementation of VoIP. The Tenor Switch is the first VoIP MultiPath device that intelligently switches calls over both IP networks and the PSTN in order to ensure high voice quality. Unlike conventional VoIP gateways that only route calls over IP networks, the Tenor Switch can transparently switch calls over to the PSTN if IP network congestion or a device failure impacts voice quality.

    The Tenor Switch thus addresses the reliability concerns that have prevented many corporate decision-makers from moving ahead with VoIP and receiving all of its benefits. It's simply the smartest, most cost-effective solution for initiating the transition to converged networks.

    Voice Quality

    Many IP networks experience unpredictable traffic characteristics resulting in jitter, lost packets and excessive latency, all of which could put the quality of enterprise phone calls at substantial and unpredictable risk.

    TASQ TM Technology Guarantees Quality of Service. The Tenor Switch's unique Transparent Auto-Switch Quality (TASQ TM ) Technology TM virtually eliminates any voice quality concern. To ensure a high quality call, TASQ Technology allows the Tenor Switch to dynamically select when to route calls through the IP network or the traditional circuit switch network. If at any time during a call the Tenor Switch senses the potential for voice quality degradation, interference or other impedance,

the call is routed transparently to the PSTN. When the IP path is clear, the call is switched back to the IP network. TASQ Technology assures that all calls are routed to provide and maintain a high quality voice connection. Callers are never aware of the switching of their call and detect no Reliability changes in their phone experience.

    Phone networks are far more reliable than the data networks that provide us with Internet and e-mail. Telephone equipment has been designed for 99.999% reliability, in which the service is down, perhaps, 3 minutes per year. Data communication equipment, such as IP routers, has substantially less reliability. The Tenor Switch is a standalone unit designed for telephony reliability. The Tenor Switch has an embedded architecture designed to support VoIP applications and is not subject to the reliability issues of router and PC-based solutions. The Tenor Switch also utilizes a unique "Pass-Through" feature to further enhance reliability. If the Switch suffers any type of failure - even loss of power - it simply becomes a wire extension of the PBX. This "Pass-Through" feature assures that phone service will never be interrupted or jeopardized!

    Easy Installation

    A Tenor Switch VoIP solution can be integrated easily into both the data communication and telecommunication infrastructures. The Tenor Switch is connected between the PBX, the PSTN and an IP router as a standalone unit consisting of a gateway and gatekeeper. Its embedded architecture eliminates the need for any additional computers, PBX hardware or software, or reconfiguration of the PBX. The user interface to the PBX doesn't change - no prefixes or two-stage dialing is required.

    The Tenor Switch is virtually 'plug and play.' Simply open any convenient web browser, enter the applicable IP address and the Tenor CAM (Configuration Alarms and Maintenance) Manager quickly guides network managers through the configuration. It utilizes SNMP for easy management, and offers LEDs and alarms for real-time system monitoring. The Tenor Switch even offers the ability to assign which calls should always go over the IP, and which should be routed over the traditional PSTN, allowing the enterprise to migrate users to VoIP.


    No one wants to connect a new piece of equipment to a data network unless it is compatible with existing equipment. Many VoIP solutions today have proprietary architectures or protocols, thus requiring a substantial, continuing commitment to a particular vendor's solution. The Tenor Switch is not dependent upon any particular vendor's product, so neither is the enterprise! The flexibility of this solution offers enterprises the luxury to explore a VoIP solution, and the ability to easily incorporate the transitional steps toward implementing a complete application-based VoIP solution.

    The Tenor Switch is also highly scalable. It is available with options to support 8, 16, 24 or 32 channels, stackable to support up to 960 simultaneous calls per stack. The Tenor Gateway connects to a PBX and PSTN via T1, E1, or PRI lines.

    For smaller and branch locations, it also supports 4 or 8 port analog and fractional T1, E1 and PRI. Cost Effective

    Many executives are concerned not with the cost of VoIP equipment, but rather with the cost of network upgrades and additional trunk cards for the PBX. Many solutions also create concerns about the cost of installing and maintaining complicated new technology.

    The Tenor Switch supports both voice and fax transmissions, allowing enterprises to save on long distance toll charges, particularly on faxes, which can always be sent over the IP network. The

Tenor Gateway can route these calls over the IP, better utilizing the WAN and avoiding the PSTN toll charges. With its hop-off capabilities, the Gateway can route

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