Specifications

4-14
Cisco ONS 15454 Troubleshooting and Maintenance Guide
November 2001
Chapter 4 Card Reference
Electrical Card Protection and the Backplane
For detailed procedures on setting up DS-1 and DS-3 protection groups, see the protection information
in the Cisco ONS 15454 Installation and Operations Guide.
4.3 Electrical Card Protection and the Backplane
Protection schemes for electrical cards differ slightly depending on the Electrical Interface Assembly
(EIA) type used on the ONS 15454 backplane. The difference is due to the varying connector size. For
example, because BNC connectors are larger, fewer DS3-12 cards can be supported when using a BNC
connector.
Note For EIA descriptions and installation, see the Cisco ONS 15454 Installation and Operations Guide.
Caution When a protection switch moves traffic from the DS3-12 working/active card to the DS3-12
protect/standby card, ports on the new active/standby card cannot be taken out of service as long as
traffic is switched. Lost traffic can result when a port is taken out of service even if the DS3-12
standby card no longer carries traffic.
4.3.1 Standard BNC Protection
When you use BNC connectors, the ONS 15454 supports 1:1 protection or 1:N protection for a total of
four working DS-3 electrical cards. If you are using EC-1 electrical cards with the BNC EIA, the ONS
15454 supports 1:1 protection and a total of four working cards. Slots 2, 4, 14 and 16 are designated
working slots. These slots are mapped to a set of 12 BNC connectors on the EIA. These slots can be used
without protection for unprotected DS-3 access.
With 1:N or 1:1 protection, Slots 1, 3, 15 and 17 are designated for protection when BNC connectors are
used. With 1:N protection, Slots 3 and 15 are also designated for protection when BNC connectors are
used. Slots 5, 6, 12, and 13 do not support DS3-12 cards when you use the regular BNC EIA.
4.3.2 High-Density BNC Protection
When you use the High-Density BNC EIA, the ONS 15454 supports 1:1 protection or 1:N protection for
eight total working DS-3 electrical cards. If you are using EC-1 electrical cards with the High-Density
BNC EIA, the ONS 15454 supports 1:1 protection and a total of eight working cards. Slots 1, 2, 4, 5, 13,
14, 16, and 17 are designated working slots.
These slots are mapped to a set of 12 BNC type connectors on the EIA. You can use these slots without
protection for unprotected DS-3 or EC-1 access. Slots 3 and 15 are designated for 1:N protection slots
when you use BNC connectors with the High-Density BNC EIA. Slots 6 and 12 do not support DS-3 or
EC-1 cards when you use the High-Density BNC EIA.
4.3.3 SMB Protection
When you use SMB connectors, the ONS 15454 supports 1:1 or 1:N protection for the DS-1 and the
DS-3 electrical cards. If you are using EC-1 cards with the SMB EIA, the ONS 15454 supports 1:1
protection. Working and protection electrical cards are defined by card slot pairs (the same card type is