3Com S7902E, Configuration Manual

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RRPP Configuration
When configuring RRPP, go to these sections for information you are interested in:
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RRPP Overview
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RRPP Configuration Task List
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Creating an RRPP Domain
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Configuring Control VLANs
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Configuring Protected VLANs
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Configuring RRPP Rings
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Activating an RRPP Domain
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Configuring RRPP Timers
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Configuring RRPP Fast Detection
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Configuring an RRPP Ring Group
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Displaying and Maintaining RRPP
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RRPP Configuration Examples
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Troubleshooting
RRPP Overview
The Rapid Ring Protection Protocol (RRPP) is a link layer protocol designed for Ethernet rings. RRPP
can prevent broadcast storms caused by data loops when an Ethernet ring is healthy, and rapidly
restore the communication paths between the nodes in the event that a link is disconnected on the ring.
Compared with the IEEE spanning tree protocols, RRPP features the following:
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Fast topology convergence
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Convergence time independent of Ethernet ring size
Background
Metropolitan area networks (MANs) and enterprise networks usually use the ring structure to improve
reliability. However, services will be interrupted if any node in the ring network fails. A ring network
usually uses Resilient Packet Ring (RPR) or Ethernet rings. RPR is high in cost as it needs dedicated
hardware. Contrarily, the Ethernet ring technology is more mature and economical, so it is more and
more widely used in MANs and enterprise networks.
Currently, both Spanning Tree Protocol (STP) and RRPP can be used to eliminate Layer-2 loops. STP is
mature; however, it takes several seconds to converge. RRPP is an Ethernet ring-specific data link layer
protocol, and converges faster than STP. Additionally, the convergence time of RRPP is independent of
the number of nodes in the Ethernet ring, and therefore, RRPP can be applied to large-diameter
networks.