Corporate networks are being squeezed from both ends by budget constraints and by the use of increasingly bandwidth-hungry multimedia applications. Even without the deployment of sophisticated streaming media, the common fact is that demands for bandwidth are ever-increasing, while the funds to deal with that situation are not unlimited.
Open system interconnection (OSI) standards have established specifications for the various layers of switching needed in networks, from the basic physical level (Layer 1), through the MAC-address level (Layer 2) and on to the more sophisticated switching that routes data packets according to protocol and content (Layer 3 to Layer 7). This advanced switching is critical for streaming media, allowing contiguous transmission of content with high quality of service (QoS).
The need is to increase this ability without increasing expenditure on network infrastructure by orders of magnitude.
This phenomenon is familiar to companies that run extensive, multiple-server networks with high Internet traffic, as Johann de Beer, systems engineer of Nortel Networks South Africa, explains.
"Content switching is part of a bigger picture," says de Beer. "Providers of services such as Internet banking, virtual shopping malls (consumer service portals, or CSPs) and content hosting (ASPs) realise that they need to optimise their infrastructure to meet the new demands on bandwidth.
"They also realise that simple expansion of the network capacity to satisfy growing demand is not cost-effective, especially where the demand fluctuates over time. The quest is, therefore, to develop architectures and models to optimise infrastructure and to make better use of technology to deliver the services. A further imperative in this type of network environment is the need for high availability. A service provider`s Web site going down means losing both customers and money."
Nortel Networks offers a range of carrier-quality network solutions that directly address these problem areas. Based on a content-delivery network (CDN) architecture, a suite of smart switching products enables large networks using web-farms - whether on copper or fibre backbones - to maximise throughput without prohibitive expansion.
The basic component is the Nortel Networks Passport 8600 routing switch, which provides the intelligent traffic management using Layer 2 to Layer 7 switching, prioritising the routing of delay-sensitive multimedia content. This is combined with the abilities of Nortel Netowrks Alteon Web Switches, which improve availability and QoS with filtering based on content, also providing load-balancing between servers, diagnostic monitoring and security functions.
Additional security is provided with Nortel Networks Contivity VPN Switches, which provide a complete solution for customers requiring secure tunnelling across managed virtual private networks. Contivity VPN Switches handle routing, bandwidth management, authentication, encryption, network address translation, data integrity, logging and firewall capabilities. The Alteon Switched Firewall then provides a final security layer which is capable of multi-gigabit throughput.
Nortel Networks Alteon SSL Accelerator offloads the processor-intensive secure socket layer functions from local servers without causing traffic delays, offering a simple solution for networks using public key infrastructure (PKI) validation of transactions.
Finally, the Alteon Content Cache enables the network to store frequently requested information closer to the user, saving up to 35% in bandwidth demand and up to 90% in Web server storage and load.
"In the context of high-usage networks, content switching is an important technology that can be deployed to save money and provide a better service," says De Beer. "The reasons for deploying content switching are to provide more secure, faster access to the data, while taking advantage of techniques such as load-balancing and SSL-offload to better utilise existing resources.
"This greatly increases the service provider`s ability to generate revenue, whether on internal, private or open, public networks. Faster access means also means happy users, with improved productivity. Finally, secure access and load-balancing protects the investment of the provider in the network as well as the knowledge resources and information transmitted."
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Nortel Networks is an industry leader and innovator focused on transforming how the world communicates and exchanges information. The company is supplying its service provider and enterprise customers with communications technology and infrastructure to enable value-added IP data, voice and multimedia services spanning Metro and Enterprise Networks, Wireless Networks and Optical Long Haul Networks. As a global company, Nortel Networks does business in more than 150 countries. More information about Nortel Networks can be found on the Web at www.nortelnetworks.com.
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