Chapter 20
| ERPS Commands
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◆ 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]
Example
Console(config-erps)#propagate-tc
Console(config-erps)#
raps-without-vc This command terminates the R-APS channel at the primary ring to sub-ring
interconnection nodes. Use the no form to restore the default setting.
Syntax
[no] raps-without-vc
Default Setting
R-APS with Virtual Channel
Command Mode
ERPS Configuration
Command Usage
◆ 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-ring. Care must also be taken to ensure that the
local RAPS messages of the sub-ring being transported over the virtual channel
into the interconnected network can be uniquely distinguished from those of
other interconnected ring R-APS messages. This can be achieved by, for
example, by using separate VIDs for the virtual channels of different sub-rings.
Note that the R-APS virtual channel requires a certain amount of bandwidth to
forward R-APS messages on the interconnected Ethernet network where a sub-
ring is attached. Also note that the protection switching time of the sub-ring
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