Specifications

4-12

Cisco ONS 15454 Troubleshooting and Maintenance Guide

November 2001

Chapter 4 Card Reference

Electrical Card Protection

4.2 Electrical Card Protection

The ONS 15454 provides a variety of electrical card protection methods. This section describes the

protection options. Figure 4-1 shows a 1:1 protection scheme and Figure 4-2 on page 4-13 shows a 1:N

protection scheme.

4.2.1 Protection, 1:1

In 1:1 protection, a working card is paired with a protect card of the same type. If the working card fails,

the traffic from the working card switches to the protect card. When the failure on the working card is

resolved, traffic automatically reverts to the working card. Figure 4-1 shows the ONS 15454 in a 1:1

protection configuration. Each working card in an odd-numbered slot is paired with a protect card in an

even-numbered slot: Slot 1 is protecting Slot 2, Slot 3 is protecting Slot 4, Slot 5 is protecting Slot 6,

Slot 17 is protecting Slot 16, Slot 15 is protecting Slot 14, and Slot 13 is protecting Slot 12. The

following electrical cards use a 1:1 protection scheme: EC1-12, DS1-14, DS3-12 and DS3-12E.

Figure 4-1 ONS 15454 cards in a 1:1 protection configuration

4.2.2 Protection, 1:N

1:N protection allows a single card to protect up to five working cards of the same DS-N level. A

DS1N-14 card protects DS1-14 cards, a DS3N-12 card protects DS3-12 cards, and DS3N-12E cards

protect DS3-12E cards. The standard DS1-14, DS3-12, and DS3-12E cards provide 1:1 protection only.

Currently, 1:N protection operates only at the DS-1 and DS-3 levels. 1:N cards have added circuitry to

act as the protection card in a 1:N protection group. Otherwise, the card is identical to the standard card

and can serve as a normal working card.

33384

1:1 Protection

TCC+

XC10G

AIC (Optional)

XC10G

TCC+

Working

Protect