Silver Peak Systems, Inc.

Most major enterprises have Voice over IP (VoIP) projects either under way, or in the testing and evaluation stage. According to a recent ComputerWorld survey, VoIP deployments will grow faster in the next 18 months than any other category of enterprise applications, with a full 16% of enterprises planning to implement VoIP in that time period.

Requirements for High VoIP Quality

VoIP is a real-time application based on UDP that is highly sensitive to WAN traffic quality – jitter, latency and packet loss. As a result, companies considering VoIP and consolidation projects will require an acceleration platform that is specifically architected to support UDP, including advanced QoS and Network Integrity capabilities to minimize jitter, latency, and packet loss.

It is not enough to simply reduce the bandwidth usage of other applications in order to make room for VoIP traffic over the WAN. Rather, it is a requirement to maintain LAN-like network characteristics over what will be an over-subscribed or congested WAN, without inducing added latency.

Silver Peak – Making the "Toll" Grade

In the VoIP world, voice quality is measured by a ‘Mean Opinion Score’, which is a number between 1 and 5 used to quantitatively express the subjective quality of speech in communications systems, especially digital networks that carry VoIP traffic. Anything above a 4.0 is considered toll grade.

The graph below shows that on a LAN it is easy to achieve a MOS of 4.4. On a WAN link with congestion, MOS drops to 3.0, which is well below toll quality. Silver Peak employs a variety of tools to return MOS above toll grade, including advanced Quality of Service (QoS) techniques, loss mitigation, and real-time data reduction. Because Network Memory works on UDP applications, for example, it is able to eliminate repetitive information across the WAN, including the constant stream of packets that are used for silence suppression in a VoIP environment. This is an enormous differentiator, enabling the Silver Peak solution to deliver toll quality voice services when other acceleration appliances cannot.

(Source: Miercom 11/05)

The Silver Peak solution also improves jitter over congested WANs, reducing it to under 1ms on average. This enables enterprises to deliver optimum VoIP performance over Silver Peak NX series appliances.