D-Link xStack Reference Manual page 125

xStack® DES-3200 Series Layer 2 Ethernet Managed Switch WEB UI Reference Guide
(ERPS Settings continued)
Parameter
RPL Port
RPL Owner
Ring MEL
Protected VLANs
Hold Off Time
Guard Time
WTR Time
Click Apply to implement changes apply the enable or disable state for ERPS, ERPS log and ERPS trap settings.
To create a new R-APS VLAN, enter the required settings in the menu and click on the Create button.
Description
Specifies the ring port as the Ring Protection Link (RPL) port. The RPL remains idle and
blocks traffic when all links on the ring are functioning. If there is a link failure on the ring
however, the RPL port is unblocked by the RPL Owner node in order to allow an alternate
path around the ring.
Enable/Disable the device as an RPL owner node. This node blocks or unblocks the RPL as
required by network conditions. An Ethernet Ring Automatic Protection Switching (R-APS)
message protocol coordinates protection activities for all nodes on the ring. In the event of a
link failure, the RPL Owner uses these messages to block a failed link and unblock the RPL.
There can be only one RPL Owner on a ring.
Specifies the ring Maintence Entity Group (MEG) level (MEL) of the R-APS function.
This command is used to configure the VLANs that are protected by the ERPS function.
Specifies the hold off time of the R-APS function. A hold off timer is used in order to
coordinate timing of ERPS at multiple levels. The purpose is to allow, for example, a server
layer switch to be able to fix the problem before switching at a client layer.
When a new defect or more sever defect is detected, the event will not be reported
immediately, instead, after the hold off timer expires, the trail that started the timer will be
checked to see if the defect still exists. If it exists, the defect is reported and the ERPS goes
into effect.
Specifies the guard time of the R-APS function. While the Guard timer is running, received
R-APS messages are NOT forwarded to the RPL Owner. The purpose of this is to prevent the
possibility a loop forming in the event that two or more R-APS signal fail messages are sent
simultaneously from different ends of the ring.
Specifies the wait-to-restore (WTR) time of the R-APS function. The WTR time defines the
amount of time mandated to pass after conditions clear. After the WTR time expires, the RPL
returns to idle state (blocking). This is used to prevent too frequent operation of ERPS due to
an intermittent signal failure defect.
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