Voice over IP (VoIP) with Silver Peak

Improve the Quality of Your VoIP System with Silver Peak

Stop garbled or dropped Voice over IP (VoIP) calls from interfering with your organization. Silver Peak fixes the network problems that degrade voice quality and disrupt phone calls while improving the survivability of VoIP systems. Calls connect more often and become clearer while branch offices can keep working, even when disaster strikes the network. With Silver Peak, VoIP becomes as clear and as reliable as the telephone network.

VoIP affords enterprises numerous benefits, but as IT extends VoIP to remote offices numerous problems and challenges begin to emerge. Audio quality often suffers. Calls may drop or fail to connect. Branch survivability during a network outage becomes more costly or complex.

The problems lie in the network. A good quality VoIP call will compensate for no more than 30ms of jitter. Yet jitter rates on congested Internet virtual private networks (VPNs) and wide area networks (WANs) can average 120 msec.  VoIP is also best run across networks with less than 1 percent random packet loss, but packet loss rates on Internet-based VPNs typically exceed one percent.

And while the codecs used by VoIP systems can minimize their bandwidth requirements, they too pose a challenge for the WAN or Internet VPNS. Even minimal amounts of bandwidth are often consumed across the WAN or a VPN by competing applications. Without the available bandwidth, calls fail to complete or are dropped.

The changing weather conditions of the Internet and to a lesser extent private WANs complicate branch office survivability. The specific challenges depend on whether the VoIP server is located in the branch office, or in the datacenter or cloud:

  • Branch office – By locating VoIP servers in branch offices, IT can divert calls to the local telephone network in the event of a network problem. The additional resilience comes at the expense of increased capital costs from adding servers to each branch office and operational costs from IT backing up and restore the large VoIP server configurations from across the WAN or Internet VPN.
  • Datacenter or cloud – By locating VoIP severs in the datacenter or cloud, IT minimizes capital costs. However, branch offices risk losing voice services in the event of a network problem.

Silver Peak helps address VoIP’s performance and availability issues. VoIP quality is improved by compensating for the effects of network congestion in real time. With a cleaner network, fewer calls drop and more calls complete. Silver Peak also monitors changing Internet conditions, diverting VoIP calls around brownouts and blackouts for better quality and availability. And by improving replication performance by 20x, Silver Peak allows IT to protect and restore server configurations significantly faster.

VoIP’s Network Challenges

More specifically, Silver Peak addresses the following conditions that disrupt VoIP implementations:

  • Congestion – Silver Peak minimizes or eliminates the effects of network congestion, making VoIP calls consistently clearer and more predictable across congested WANs. Silver Peak’s Adaptive Forward Error Correction (FEC) reconstitutes lost packets in real-time, avoiding delays from packet retransmission. Real-time Packet Order Correction (POC) also minimizes delay, by resequencing out-of-order packets in real-time. Quality of Service (QoS) and traffic shaping guarantee VoIP receives the necessary bandwidth on congested networks.  The culmination of those capabilities has been shown to practically eliminate 120 msec of jitter from a connection, allowing better than toll-grade audio over a network that could previously only support poor quality phone calls.
  • Bandwidth Silver Peak byte-level deduplication eliminates redundant data across the WAN. The first time a VoIP call is initiated, data patterns are fingerprinted and compressed by Silver Peak. Subsequent requests are fulfilled by the local Silver Peak instance. Silver Peak’s deduplication improves VoIP quality by minimizing the bandwidth consumed by packet overhead and by reducing the bandwidth consumed by other applications sharing the network, freeing up bandwidth for VoIP calls. Replication performance is also improved by 20x, making protecting remote VoIP servers significantly easier and faster.
  • Latency – Silver Peak mitigates latency, improving the collaboration tools accompanying VoIP in a unified communications client. Silver Peak’s TCP Acceleration includes windows scaling, selective acknowledgements, and HighSpeed TCP.  When bandwidth is consumed by sharing or accessing files with the Common Internet File System (CIFS), VoIP can indirectly benefit from CIFS Acceleration, which includes CIFS read-ahead, CIFS write-behind, and CIFS metadata optimizations.  Latency is also reduced through packet coalescing, which re-packages multiple smaller packets into a single larger one, and through Dynamic Path Control, which selects the fastest path to a remote location.

Branch Survivability

Silver Peak also helps IT ensure the availability and survivability of branch office voice services. A cleaner network with more available bandwidth improves call completion rates and makes protecting and restoring remote call server configurations easier and faster.

Coupling Silver Peak’s native intelligence with a dual-homed architecture also eliminates the implicit risks of centralizing VoIP servers. With dual-homing, the Silver Peak instance in the branch office is connected to two networks, such as MPLS and the Internet or two Internet connections.

Silver Peak constantly monitors the performance of those connections, identifying the optimum path for carrying VoIP (and any other application). In the event of an outage or even a slow-down on a given path, the Silver Peak instance directs traffic to an alternative path before a user detects a degradation in performance. This way organizations can benefit of redundancy and availability without paying for wasted bandwidth. 

Silver Peak: The Right Choice for VoIP

VoIP security is also enhanced with Silver Peak. All site-to-site traffic is protected by Silver Peak’s Accelerated IPSec virtual private network (VPN), which runs AES-256, the enterprise standard for data encryption. Data-at-rest in Silver Peak instances is also encrypted with AES.

In short, Silver Peak offers the most scalable and cost-effective solution for improving the quality and availability of an enterprise VoIP solution. See for yourself by downloading and deploying a free, self-service trial in just 20 minutes, or contact us to see how Silver Peak can help your organization. 

Featured Products

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  • Increase user satisfaction by delivering a more predictable and responsive voice experience.  
  • Improve branch office survivability without impacting performance or bandwidth.
  • Backup and restore VoIP server configuration databases faster, more effectively.
  • Reduce bandwidth charges by eliminating redundant data from the WAN.
  • Improve productivity by allowing employees everywhere to collaborate more effectively.  


  • 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.
  • There are a variety of reasons why enterprises deploy satellite technology for Wide Area Network (WAN) communications. Whether fixed VSAT (e.g. Very Small Aperture Terminals) or mobile BGAN (e.g. Broadband Global Area Network), satellite provides a reliable means of establishing connectivity when terrestrial services are not widely available or not ideal.
  • All too often, the Wide Area Network (WAN) link is the weak link in data protection. Limited bandwidth, high latency, lost packets, and out-of-order packets can all jeopardize strategic data replication and backup initiatives, resulting in missed Recovery Point Objectives and Recovery Time Objectives (RPO/RTO).