Aps +1 Redundancy Criteria; Figure 26-5 Sonet Aps 1+1 Detail - Cisco BPX-BXM-155-8DX Installation And Configuration Manual

Chapter 26 Configuring SONET Automatic Protection System
The receiver terminating the APS 1+1 has to select cells from either the working or protection line and
be able to forward one consistent traffic stream. Since both working and protection line transport
identical information, the receiving ends can switch from one to the other without the need for
coordinating with the transmit end.

Figure 26-5 SONET APS 1+1 Detail

Tx
Rx
To set up APS, the addapsln command is used.
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•
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When no port on a BXM is configured for APS, each backcard of the pair may be used independently
by independent front cards. The switch software disallows configuration of APS if independent usage
is detected. There must be no active lines on the card that is selected to be the secondary card.
With previous card cages, because of the positioning of mechanical dividers, the APS card pairs can
only be inserted in certain slots. These are slots 2 through 5 and 10 through 13. The mechanical dividers
are located at slots 1 and 2, 5 and 6, 9 and 10, and 13 and 14.
With current card cages, this limitation is removed, and the APS card pairs can be located anywhere,
except BCC cards slots 7 and 8, and ASM card slot 15.
An APS 1+1 redundant card pair must be in adjacent slots (2,3 or 4,5 and so on).

APS +1 Redundancy Criteria

To implement the APS 1+1 redundancy:
Step 1 Set up Y-redundancy
Step 2 Then add APS
Ensure that these requirements are met:
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Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
Xcvr
Xcvr
The addapsln command defines which line is working and which is protection.
Before you can execute the addapsln command for a line pair, the protection line must be in the
standby state.
If the addapsln command is executed, the working line is always initially selected.
The two BXM front cards reside in the same two adjacent slots as the APS backcards
Working line
Xcvr
Xcvr
Protection line
Cisco BPX 8600 Series Installation and Configuration
APS 1+1 (Card and Line Redundancy)
Rx
Tx
26-7