Web Management Guide-R04

Table Of Contents
Chapter 13
| Basic Administration Protocols
Ethernet Ring Protection Switching
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Major Domain – The ERPS ring used for sending control packets.
This switch can support up to six rings. However, ERPS control packets can only
be sent on one ring. This parameter is used to indicate that the current ring is a
secondary ring, and to specify the major ring which will be used to send ERPS
control packets.
The Ring Protection Link (RPL) is always the west port. So the physical port on a
secondary ring must be the west port. In other words, if a domain has two
physical ring ports, this ring can only be a major ring, not a secondary ring (or
sub-domain) which can have only one physical ring port. The major domain
therefore cannot be set if the east port is already configured.
Node ID – A MAC address unique to the ring node. The MAC address must be
specified in the format xx-xx-xx-xx-xx-xx or xxxxxxxxxxxx. (Default: CPU MAC
address)
The ring node identifier is used to identify a node in R-APS messages for both
automatic and manual switching recovery operations.
For example, a node that has one ring port in SF condition and detects that the
condition has been cleared, will continuously transmit R-APS (NR) messages
with its own Node ID as priority information over both ring ports, informing its
neighbors that no request is present at this node. When another recovered
node holding the link blocked receives this message, it compares the Node ID
information with its own. If the received R-APS (NR) message has a higher
priority, this unblocks its ring ports. Otherwise, the block remains unchanged.
The node identifier may also be used for debugging, such as to distinguish
messages when a node is connected to more than one ring.
R-APS with VC – Configures an R-APS virtual channel to connect two
interconnection points on a sub-ring, allowing ERPS protocol traffic to be
tunneled across an arbitrary Ethernet network. (Default: Enabled)
A sub-ring may be attached to a primary ring with or without a virtual
channel. A virtual channel is used to connect two interconnection points
on the sub-ring, tunneling R-APS control messages across an arbitrary
Ethernet network topology. If a virtual channel is not used to cross the
intermediate Ethernet network, data in the traffic channel will still flow
across the network, but the all R-APS messages will be terminated at the
interconnection points.
Sub-ring with R-APS Virtual Channel – When using a virtual channel to
tunnel R-APS messages between interconnection points on a sub-ring, the
R-APS virtual channel may or may not follow the same path as the traffic
channel over the network. R-APS messages that are forwarded over the
sub-ring’s virtual channel are broadcast or multicast over the
interconnected network. For this reason the broadcast/multicast domain of
the virtual channel should be limited to the necessary links and nodes. For
example, the virtual channel could span only the interconnecting rings or
sub-rings that are necessary for forwarding R-APS messages of this sub-