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Transition Networks
S4224 Web User Guide
33558 Rev. C
Page 250 of 669
indicates that no Port 1 SF MEP is associated with this instance. Assign an integer value of
1
-
32
.
Port 0 SF MEP and Port 1 SF MEP cannot be the same. Note that the number refers to the MEP
instance number and not the MEP ID (which may or may not be the same).
Port 0 APS MEP
This is the Port 0 APS PDU handling MEP. Assign an integer value of
1
-
32
. The Port 0 APS MEP
and Port 1 APS MEP cannot be the same. Note that the number refers to the MEP instance number
and not the MEP ID (which may or may not be the same).
Port 1 APS MEP
The Port 1 APS PDU handling MEP. As only one APS MEP is associated with interconnected sub-
ring without virtual channel, it is configured as "
0
" for such ring instances. "
0
" in this field indicates
that no Port 1 APS MEP is associated with this instance. Assign an integer value of
1
-
32
. The Port 0
APS MEP and Port 1 APS MEP cannot be the same. Note that the number refers to the MEP
instance number and not the MEP ID (which may or may not be the same).
Ring Type
Type of Protection ring. It can be either
Major
ring or
Sub
-ring.
Major
ring: the Ethernet ring that is connected on two ports to an interconnection node.
Sub
-ring: an Ethernet ring which is connected to one or more other Ethernet rings or networks
through the use of a pair of interconnection nodes. On their own, the sub-ring links do not form a
closed loop. A closed connection of traffic may be formed by the sub-ring links and one or more links,
that are controlled by other Ethernet ring(s) or network(s), between interconnection nodes.
ERPS Instance Configuration
Configured
Displays a green LED (
) for Up or a red LED (
) for Down.
Red
: This ERPS is only created and has not yet been configured and is not active.
Green
: This ERPS is configured and is active.
Guard Time
Enter the Guard timeout value to be used to prevent ring nodes from receiving outdated R-APS
messages. The period of the guard timer can be configured in 10 ms steps between
10 ms
and
2 seconds
, with a default value of
500 ms
. The guard timer is used to prevent Ethernet ring nodes
from acting on outdated R-APS messages, and prevents the possibility of forming a closed loop. The
guard timer is activated whenever an Ethernet ring node receives an indication that a local switching
request has cleared (i.e., Local Clear SF, Clear). This guard timer period should be greater than the
maximum expected forwarding delay in which an R-APS message traverses the entire ring. The
longer the period of the guard timer, the longer an Ethernet ring node is unaware of relevant new or
existing requests transmitted from other Ethernet ring nodes, and therefore unable to react to them. A
guard timer is used in every Ethernet ring node. Once a guard timer is started, it expires by itself.
When the guard timer is not running, the R-APS request/state and status information is forwarded
unchanged.
WTR Time
The Wait To Restore timing value to be used in revertive switching. You can set the WTR period to
1
minute or from
5
-
12
minutes in 1 minute steps. The default value is
5
minutes. In revertive mode, the
wait to restore (WTR) timer is used to prevent frequent operation of the protection switching due to
intermittent signal failure defects.