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Ethernet Protection Switching Ring (EPSR) is Allied Telesis’ premier solution for providing extremely fast failover between nodes in a resilient ring. EPSR enables rings to recover within as little as 50ms, preventing a node or link failure from affecting customer experience, even with demanding applications such as IP telephony and streaming video.

IP over Ethernet is now a well-proven technology in the delivery of converged services. Ethernet-based Triple-Play services have become an established commercial reality worldwide, with service providers offering advanced voice, video and data packages to their customers. This requires a highly available network infrastructure for service providers to meet Service Level Agreements (SLAs), and meet the expectations of customers for a seamless multimedia experience.

Now, the convergence of services and applications in the enterprise has led to increasing demand for high availability in the Local Area Network (LAN). High bandwidth is also required for the multiple applications simultaneously using the network. For many businesses, real-time applications like surveillance, automated control, video streaming and Voice over IP (VoIP) are used right alongside data and Internet access.

The key to providing maximum network uptime is extremely rapid failover in the event of link failure. Allied Telesis’ carrier-grade resiliency feature, Ethernet Protection Switching Ring (EPSR), ensures mission critical services are not interrupted in the event of link or node outages. EPSR provides failover times as low as 50ms, and can be coupled with today’s fastest Ethernet speeds of 10, 40, or 100Gbps.

A number of Allied Telesis products also support the standards-based G.8032 Ethernet Ring Protection, which similarly provides high-speed ring connectivity and failover as low as 50ms. G.8032 Ethernet Ring Protection can be deployed stand-alone, or interoperate with Allied Telesis ESPR.

Equally as at home in the enterprise network as it is in demanding service provider metro networks, EPSR provides a solution that meets the modern network requirements of high bandwidth and high availability. This advanced self-healing network technology provides ‘always-on’ access to online resources and applications.

Allied Telesis supports this technology on a wide range of sophisticated switching platforms, as well as advanced telecommunication chassis.

EPSR in Metro Networks

Service Provider Metro networks require extremely high reliability, as these city-wide networks provide online access to many businesses, and multi-media Triple-Play services (data, voice and video) to many homes. With SLAs to meet, any outage is both costly to the service provider, and disruptive for customers.

EPSR is an ideal solution for the delivery of converged services in the Metro environment with the following key advantages:
  • Long-distance: Geographically spread-out nodes are supported as fiber allows long-distance connectivity.
  • High availability: With no discernible outage in the event of a link or node failure, EPSR provides the perfect solution for service providers meeting SLAs.
  • High performance: Connectivity to voice, video and data services is always maintained for a seamless customer experience.
  • Multi-speed support: The distribution and access rings can run at different speeds appropriate to the amount of network traffic.
  • Network protection: The use of EPSR SuperLoop Prevention (SLP) ensures there is no chance of a loop forming, or any subsequent network storm, in this multi-ring environment.

A multi-ring EPSR-SLP design is shown in diagram 5. This city-wide Metro network provides high-performing online access for businesses and advanced Triple-Play services to residential customers.