ECS4110-28T_Management Guide

C HAPTER 14 | Basic Administration Protocols
Ethernet Ring Protection Switching
– 510 –
Figure 288: Sub-ring without Virtual Channel
◆ R-APS Def MAC – Sets the switch’s MAC address to be used as the
node identifier in R-APS messages. (Default: Enabled)
When ring nodes running ERPSv1 and ERPSv2 co-exist on the same
ring, the Ring ID of each ring node must be configured as “1”.
If this command is disabled, the following strings are used as the node
identifier:
■
ERPSv1: 01-19-A7-00-00-01
■
ERPSv2: 01-19-A7-00-00-[Ring ID]
◆ Propagate TC – Enables propagation of topology change messages
from a secondary ring to the primary ring. (Default: Disabled)
When a secondary ring detects a topology change, it can pass a
message about this event to the major ring. When the major ring
receives this kind of message from a secondary ring, it can clear the
MAC addresses on its ring ports to help the second ay ring restore its
connections more quickly through protection switching.
When the MAC addresses are cleared, data traffic may flood onto the
major ring. The data traffic will become stable after the MAC addresses
are learned again. The major ring will not be broken, but the bandwidth
of data traffic on the major ring may suffer for a short period of time
due to this flooding behavior.
◆ Non-ERPS Device Protection – Sends non-standard health-check
packets when an owner node enters protection state without any link
down event having been detected through Signal Fault messages.
(Default: Disabled)
■
The RPL owner node detects a failed link when it receives R-APS
(SF - signal fault) messages from nodes adjacent to the failed link.
The owner then enters protection state by unblocking the RPL.
However, using this standard recovery procedure may cause a non-
EPRS device to become isolated when the ERPS device adjacent to it
detects a continuity check message (CCM) loss event and blocks the
link between the non-ERPS device and ERPS device.
CCMs are propagated by the Connectivity Fault Management (CFM)
protocol as described under "Connectivity Fault Management" on
page 520. If the standard recovery procedure were used as shown
Sub-ring
with Virtual
Channel
RPL Port
Interconnection Node
Ring Node
Major Ring