Introduction to Redundant Pairs — a Powerful, Flexible Add-on to Alpha Ring

For over six years, EtherWAN's Alpha Ring protocol has delivered efficient redundancy options with a failover time of less than 15 milliseconds. With the release of firmware version 1.94.5, EtherWAN has made several enhancements to this powerful tool. One enhancement, Redundant Pair protocol, is specifically designed to overcome certain limitations of Ring Coupling, the method used to connect multiple Alpha Rings. The Redundant Pair protocol provides improved flexibility, unrestricted expansion, and more cost-effective configuration options...<read more>

• Any 2 paths can be selected to back each other up, allowing for flexible network design
• Up to 253 pairs are supported in complex network topologies, providing improved network scalability and unrestricted expansion
• Fast failover time < 50ms
• Works with third-party Ethernet switches, and currently supported by EtherWAN
  EX70900, EX61000A, EX71000, EX62000, EX72000, EX63000, EX73000, EX83000, EX74000, EX75000, EX76000, EX78000, EX78162, EX78602, EX27000, EX77000, EX87000, EX29000, EX89000 series.

• Each redundant pair is comprised of two paths: The ports connecting each path are defined as either "Normal" or "Slave"
• The same role (Normal or Slave) must be used on the same side.
• Redundant pair is an event-based protocol. When a link in a Redundant Pair fails, the message is passed through the Alpha Ring path, and the backup link is activated within 50 milliseconds

• The Redundant Pair protocol offers extreme flexibility in designing a network, and ensures that uptime is maximized through multiple redundancies.