Using Wan Groups - Zhone IMACS 8000 User Manual

WAN Card
RDNT RULES
The selection of Redundancy Rules will define the method of determining what event will
trigger a WAN port to switch to its redundant mate. The options are none, OOS, and CGA.
GROUP
The Group setting identifies a method of link-fail alarm propagation from upstream trunks to
downstream tributaries when the system is configured for alarm transcoding.
The selection of a group is a two-step process. After identifying the group number (1 to 4),
select the secondary group (A [child group], B [child group] or C [parent group]).
Figure 9-18 shows two system units with "parent-child" groupings. The child groups are
designated as "A" and "B." The parent groups are designated "C".
Tributary
Device #1
The WAN links between the Device and the System Unit (A, B, A1, and B1) are called
tributaries. The WAN link between the two SYS Units (C and C1) is referred to as a trunk.
In the normal condition (no WAN groups selected), a failure on any of the tributaries
supplying Device 1 would be reported at SYS 1 and Device 1 only. A failure of the trunk from
C to C1 would be reported at SYS 1 and 2 only.
When Groups are created at both system units, a trunk failure (C to C1) will inform all of the
associated tributaries (A and B, A1 and B1) of that condition.
When groups are used in conjunction with the Network Management option (mentioned
earlier) and the AIS/ALM is set to tcodr, a failure of any of the tributaries will propagate the
failure through the trunk to the associated tributary at the other end (A to A1 or B to B1).
The following notification procedure is followed:
1. A Loss of Signal, Loss of Frame, Error Rate Exceeded, or AIS failure of the transmit
leg of W1-1(A) occurs between Device 1 and SYS 1.
System Cards
W1-1 (A)
W1-2 (B)
O C
R M
G
R
System #1
Figure 9-18.Using WAN Groups
WAN Card User Screens and Settings
Trunk
(C) (C)
W2-1
O C
R M
G
R
System #2
Tributary
W3-1 (A)
W3-2 (B)
Device #2
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