Rockwell Automation Ethernet Design Considerations Reference Manual - Manual (Page 51)

Rockwell Automation Publication ENET-RM002C-EN-P - May 2013 51
Ethernet Infrastructure Features Chapter 3
Resilient Ethernet Protocol (REP)
REP operates on chain of bridges called segments. A port is assigned to a unique
segment. A segment can have up to two ports on a given bridge. REP is built in to
Stratix 8000 and Stratix 8300 switches.
REP supports closed and open rings in various topologies:
• Redundant networks can be built with REP segments
• Only ring resiliency protocol applicable to both Industrial and IT
applications
• Ring recovery time is less than 70 ms for both unicast and multicast traffic
in fiber implementations
REP is a segment concept. A segment is a chain of bridges.
When all links are operational, a unique port blocks the traffic on the segment. If
any failure occurs within the segment, the blocked port goes forwarding.
REP Segment
Interface f2
rep segment 10 Interface f1
rep segment 10 Interface f1
rep segment 10
Interface f2
rep segment 10
g1/1 g1/2 g1/1 g1/1 g1/1 g1/1 g1/2 g1/2 g1/2 g1/2
REP Segment
Interface g1/2
REP segment 10
Interface g1/1
REP segment 10
Interface g1/2
REP segment 10
Interface g1/1
REP segment 10
Edge Port
g1/2 Block Traffic
Edge Port
g1/2 Unblock
Link Failure
g1/1 g1/1 g1/1 g1/1 g1/1
g1/1 g1/1 g1/1 g1/1 g1/1
g1/2 g1/2 g1/2 g1/2 g1/2
g1/2 g1/2 g1/2 g1/2 g1/2