Revertive Switching; N Protection Guidelines - Cisco 15454-DS1-14= - 1.544Mbps Expansion Module Reference Manual

7.1.2 1:N Protection
Table 7-2
Working Card
DS3/EC1-48
DS3XM-12
(Transmux)
DS3XM-12
(Transmux)
1. A high-density electrical card inserted in Slot 1 restricts the use of Slots 5 and 6 to optical, data, or storage cards.
2. A high-density electrical card inserted in Slot 2 restricts the use of Slots 4 and 6 to optical, data, or storage cards.
3. A high-density electrical card inserted in Slot 16 restricts the use of Slot 14 to optical, data, or storage cards.
4. A high-density electrical card inserted in Slot 17 restricts the use of Slots 12 and 13 to optical, data, or storage cards.
5. A high-density electrical card inserted in Slot 1 restricts the use of Slots 5 and 6 to optical, data, or storage cards.
6. A high-density electrical card inserted in Slot 2 restricts the use of Slots 4 and 6 to optical, data, or storage cards.
7. A high-density electrical card inserted in Slot 16 restricts the use of Slot 14 to optical, data, or storage cards.
8. A high-density electrical card inserted in Slot 17 restricts the use of Slots 12 and 13 to optical, data, or storage cards.
9. Portless DS-3 Transmux operation does not terminate the DS-3 signal on the EIA panel.

7.1.2.1 Revertive Switching

1:N protection supports revertive switching. Revertive switching sends the electrical interfaces (traffic)
back to the original working card after the card comes back online. Detecting an active working card
triggers the reversion process. There is a variable time period for the lag between detection and
reversion, called the revertive delay, which you can set using the ONS 15454 software, Cisco Transport
Controller (CTC). To set the revertive delay, refer to the "Turn Up a Node" chapter in the
Cisco ONS 15454 Procedure Guide. All cards in a protection group share the same reversion settings.
1:N protection groups default to automatic reversion.
Caution A user-initiated switch (external switching command) overrides the revertive delay, that is, clearing the
switch clears the timer.

7.1.2.2 1:N Protection Guidelines

There are two types of 1:N protection groups for the ONS 15454: ported and portless. Ported 1:N
interfaces are the traditional protection groups for signals electrically terminated on the shelf assembly.
Portless 1:N interfaces are signals received through an electrical synchronous transport signal (STS)
through the cross-connect card. The DS3XM-12 card supports portless as well as traditional ported
deployments.
type.
The following rules apply to ported 1:N protection groups in the ONS 15454:
•
•
Cisco ONS 15454 Reference Manual, R8.5
7-4
Supported 1:N Protection by Electrical Card (continued)
Protect Card
DS3/EC1-48
DS3XM-12
(Transmux)
DS3XM-12
(Transmux)
Table 7-2 on page 7-3
Working and protect card groups must reside in the same card bank (Side A or Side B).
The 1:N protect card must reside in Slot 3 for Side A and Slot 15 for Side B.
Protect Group
(Maximum)
N < 2
N < 5
N < 7
9
(portless )
outlines the 1:N configurations supported by each electrical card
Chapter 7
Working Slot Protection Slot
5 6
1 , 2 3
7 8
16 , 17 15
1, 2, 4, 5, 6 3
12, 13, 14, 16, 17 15
1, 2, 4, 5, 6, 12, 13, 3
14, 15, 16, 17
1, 2, 3, 4, 5, 6, 12, 15
13, 14, 16, 17
Card Protection
78-18106-01