Ethernet Ring Protection Switching (ERPS) is the first industry standard (ITU-T G.8032) for ERPS. It is achieved by integrating mature Ethernet operations, administration, and maintenance (OAM) * functions and a simple automatic protection switching (APS) protocol for Ethernet ring networks. ERPS provides sub-50ms protection for Ethernet traffic in a ring topology. It ensures that there are no loops formed at the Ethernet layer.
One link within a ring will be blocked to avoid Loop (RPL, Ring Protection Link). When the failure happens, protection switching blocks the failed link and unblocks the RPL. When the failure clears, protection switching blocks the RPL again and unblocks the link on which the failure is cleared.
G.8032 Terms and Concepts
RPL (Ring Protection Link) – Link designated by mechanism that is blocked during Idle state to prevent loop on Bridged ring
RPL Owner – Node connected to RPL that blocks traffic on RPL during Idle state and unblocks during Protected state
R-APS (Ring – Automatic Protection Switching) - Protocol messages defined in Y.1731 and G.8032 used to coordinate the protection actions over the ring through RAPS VLAN (R-APS Channel).
RAPS VLAN (R-APS Channel) – A separate ring-wide VLAN for transmission of R-APS messages Protected VLAN – The service traffic VLANs for transmission of normal network traffic
This window is used to enable the ERPS function on the switch.
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NOTE: STP and LBD should be disabled on the ring ports before enabling ERPS. The ERPS cannot be enabled before the R-APS VLAN is created, and ring ports, RPL port, RPL owner, are configured.
To view the following window, click L2 Features > ERPS Settings, as shown below:
Figure 4-106 ERPS Settings Window
The fields that can be configured are described below:
Parameter Description
ERPS State Click to enable or disable the ERPS State.
ERPS Log Click to enable or disable the ERPS Log.
ERPS Trap Click to enable or disable the ERPS Trap.
R-APS VLAN (1-4094) Specify the VLAN which will be the R-APS VLAN.
Click the Apply button to accept the changes made for each individual section.
Click the Find button to find a specific entry based on the information entered.
Click the View All button to view all the entries configured.
Click the Delete button to remove the specific entry.
Click the Detail Information link to view detailed information of the R-APS entry.
Click the Sub-Ring Information link to view the Sub-Ring information of the R-APS entry.
Enter a page number and click the Go button to navigate to a specific page when multiple pages exist.
After clicking the Detail Information link, the following window will appear:
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Figure 4-107 ERPS Settings - Detail Information window
Click on the Edit button to re-configure the specific entry.
Click on the <<Back button to return to the ERPS settings page.
After click the Edit button, the following window will appear:
Figure 4-108 ERPS Settings - Edit Detail Information window
The fields that can be configured or displayed are described below:
Parameter Description
R-APS VLAN Here the R-APS VLAN ID will be displayed.
Ring Status Specify to enable or disable the specified ring.
Admin West Port Specify the port as the west ring port and also specify the virtual port channel used.
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Operational West Port Here the operational west port value will be displayed.
Admin East Port Specify the port as the east ring port and also specify the virtual port channel used.
Operational East Port Here the operational east port value will be displayed.
Admin RPL Port Specify the RPL port used. Options to choose from are West Port, East Port, and None.
Operational RPL Port Here the operational RPL port value will be displayed.
Admin RPL Owner Specify to enable or disable the RPL owner node.
Operational RPL Owner
Here the operational RPL owner value will be displayed.
Protected VLAN(s) Specify to add or delete the protected VLAN group.
Ring MEL (0-7) Specify the ring MEL of the R-APS function. The default ring MEL is 1.
Holdoff Time (0-10000) Specify the hold-off time of the R-APS function. The default hold-off time is 0 milliseconds.
Guard Time (10-2000) Specify the guard time of the R-APS function. The default guard time is 500 milliseconds.
WTR Time (5-12) Specify the WTR time of the R-APS function.
Revertive Specify the state of the R-APS revertive option.
Current Ring State Display the current Ring state.
Click the Apply button to accept the changes made.
Click the <<Back button to return to the previous window.
After clicking the Sub-Ring Information link, the following window will appear:
Figure 4-109 ERPS Sub-Ring Settings window
The fields that can be configured are described below:
Parameter Description
R-APS VLAN Here the R-APS VLAN ID will be displayed.
Sub-Ring R-APS VLAN Enter the Sub-Ring R-APS VLAN ID used here.
State Specify the ERPS Sub-Ring state here. Options to choose from are Add and Delete.
TC Propagation State Specify the TC Propagation state here. Options to choose from are Enabled and Disabled.
Click the Apply button to accept the changes made.
Click the <<Back button to return to the previous window.
LLDP
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