Juniper JUNOS OS 10.4 Manual page 175

Copyright © 2012, Juniper Networks, Inc.
the ring coordinate protection activities by exchanging messages through the Ethernet
ring automatic protection switching (R-APS) messaging protocol. Each ring instance has
an RPL owner. The ring-1 RPL owner is CS1; the ring-2 RPL owner is CS2. The RPL owners
block or unblock the RPL as conditions require and initiate R-APS messages.
Each ring instance has two interface ports (an east interface and a west interface) that
participate in the instance. Interface
protection link end where ring-2's RPL terminates. Interface
on CS1, is the ring protection link end where ring-1's RPL terminates.
Each ring instance has a data channel. A data channel is a group of bridge domain virtual
LAN (VLAN) IDs. All VLAN IDs within the same ring interface share the same
data-forwarding properties controlled by the ERP. The data channel on ring-1 is [200,
300]. The data channel on ring-2 is [500, 600].
Two customer site switches are connected to AS1. Customer site 1 uses VLANs 200 and
300. Customer site 2 uses VLANs 500 and 600.
Figure 24: ERP with Multiple Protection Instances Configured on Three
MX Series Routers
ring-1
data-channel [200,300]
RPL owner
ring-1
CS1
ge-3/2/4.0
east-interface
RP link end ring-1
Table 5 on page 156 describes the components of the example topology.
ge-2/0/8.0 , the west interface on CS2, is the ring
data-channel [500,600]
ge-5/2/3.0
west-interface
ge-2/0/5.0 ge-2/1/1.0
west-interface east-interface
AS1
Customer Site 1 Customer Site 2
VLANs [200,300] VLANs [500,600]
Chapter 13: Ethernet Ring Protection
, the east interface
ge-3/2/4.0
ring-2
RPL owner
ring-2
ge-2/0/4.0
CS2
east-interface
ge-2/0/8.0
west-interface
RP link end ring-2
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