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VoIP/SIP Traffic Management Solutions

Increasingly, service providers and enterprises are adopting SIP-based technologies to drive their mainstream commercial and business-critical communication services, including VoIP and messaging. As these critical services move from traditional PBX and analog infrastructure to IP-based applications, the need for intelligent traffic management and network-centric high-availability solutions becomes acute to maintain service quality and uptime. Foundry's ServerIron family delivers high availability, scalability and security to SIP server farms that are a key source of revenue for service providers and critical links for communications within enterprise organizations.

Overview

In the mid nineties, Web technologies revolutionized commerce and business transactions by enabling a wave of Web-based application services. No other technology has since been more widely deployed and used by businesses, people and organizations. Session Initiation Protocol (SIP) and Voice over IP (VoIP) technologies are promising a similar revolution in communication services. IP-based communication services are being deployed by most major providers, and are growing in prominence with end users. Although IP-based voice communication is a small percentage of the overall communication services business today, it is bound to be the predominant service in the years ahead. New value-added services, including messaging and streaming, will migrate to an IP infrastructure using the highly-flexible and extensible SIP technologies.

When Web technologies and services became critical business drivers for most organizations, and in many cases life support systems for businesses, the limitations of traditional server farm and application models became obvious. Poor availability, application performance, security and infrastructure scalability became insurmountable hurdles to delivering business-class IP and Web services. Layer 4-7 load balancing and Web switching solutions emerged as the technology of choice to overcome these limitations. Application-aware networking devices were deployed in front of the Web server farms to build a virtualized infrastructure, which was resilient, scalable and secure, and is totally transparent to the end user. These switches delivered service resilience from server failures, on-demand and unlimited server farm scalability with commodity servers, and optimized performance by efficient server selection and acceleration. The application switches continue to evolve, even today, to deliver even more value-added optimization and acceleration capabilities for Web applications and services.

Today, service providers, carriers and Enterprises face a similar set of challenges in deploying IP-based communication services – poor service availability due to server and application failures, lack of scalability due to server limitations, and poor performance and quality of service for voice communications. These challenges have a magnified impact on voice services due to the stringent quality and uptime requirements and expectations for these communication services. Additionally, capacity and performance demands are significantly higher for voice services because of the high volume of sessions and users. Businesses can overcome these challenges with innovative, cost-effective and commercially proven application switching solutions.

Foundry's ServerIron switches feature advanced SIP application intelligence to deliver the benefits of high availability, scalability, security and performance to IP-based communication services. The ServerIron switches front-end the SIP servers and deliver high availability, accelerated performance, on-demand scalability and robust security to IP-based communication services. These switches feature highly sophisticated and customizable SIP application intelligence to efficiently manage SIP traffic, and support advanced health monitoring at the SIP application level to ensure service availability and best response time. Each new SIP session is assigned to one of the *best* servers based on load and other metrics. All messages belonging to a given SIP session are forwarded to the same server to preserve transaction integrity. The ServerIron switches also protect the SIP servers from various types of attacks by filtering SIP messages based against user-configurable and highly-customizable content rules.

One of the key functions of an application switch is its ability to monitor the health of the servers and applications in real time, and react to failures or performance degradation by re-directing clients to alternative resources. The ServerIron switch provides highly customizable SIP-specific health monitoring to rapidly determine any degradation or failure of SIP servers and application functions. The switches send REGISTER and OPTIONS messages to the SIP Proxy and Registrar servers. When an error-free response is received, the ServerIron switch marks the server as being available, and starts assigning new SIP sessions to the available servers. Health monitoring messages are user configurable per server and per application port. The switches periodically send health monitoring messages at a user-configured frequency, which can be as low as once every one second per server. Foundry's unique system architecture includes a dedicated processor for health monitoring and device management, which significantly increases the reliability and efficiency of health monitoring and therefore improves the overall service availability.

The ServerIron application switches act as a first line of defense to the SIP servers and applications by preventing illegal users and traffic from flowing through to the servers. Attacks against IP services are extremely common, and because the servers and applications are poorly prepared to defend, the attacks severely impact service availability. The ServerIron switches validate SIP messages for protocol conformance, including specific protocol version, prior to forwarding the request to a server. Additionally, the switches filter illegal SIP message types. By filtering and discarding illegal messages early in the network, the ServerIron switches help offload servers from processing illegal messages and increase the available server capacity for legitimate SIP traffic. Foundry solution also supports various rate limiting capabilities to prevent application and server abuse by enforcing *normal* service behavior by end users.

Service providers and traditional carriers are increasingly deploying IP-based voice infrastructure to deliver high-value revenue-generating communication services to their business and end-user customers. SIP-based applications are at the foundation of delivering these services, and these applications must maintain highest availability and superior scalability to match the voice service expectations and demands.

Foundry Networks is integrating advanced SIP application intelligence into the industry-leading high-performance ServerIron family of application switches to deliver ultra high availability, superior scalability and robust security to the IP-based communication service infrastructure. The ServerIron switches are the industry's only proven high-performance solution designed to meet the demands of large service providers and carrier customers. These switches scale to millions of calls, and deliver performance of tens of thousands of calls per second. With built-in advanced security features, the Foundry switches also help fortify the SIP server farm, which increases service availability.

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Related Products

Foundry's application switching solutions are available on a range of ServerIron products purpose-built with ASIC-based and network-centric architecture to deliver highest availability, performance and scalability when deployed in business-critical application infrastructures. The ServerIron family of products feature the high-intelligent TrafficWorks OS to deliver a full range of application switching solutions cusotmizable to the customer environment.

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