Restrictions - Cisco ONS 15454 Reference Manual

2.8.1 Restrictions

There are two roll modes:
•
•
If you have created a roll on the circuit and it has detected a valid signal, do not cancel it. Cancelling a
Caution
valid roll will cause a traffic hit of more than 1300 ms. If you want to revert back from a valid roll,
complete the roll and use bridge and roll again to roll it back.
Caution Performing bridge and roll on an STS-192C (ONS 15454) might cause a traffic hit of 50 ms.
Note The path width rules for creating circuits apply when rolling circuits. For example, if you roll an STS3c
starting at STS#1, you cannot roll it to another port and start it at STS#2. You have to start it at STS#1.
2.8.1 Restrictions
The following restrictions apply for bridge and roll using TL1 in this release:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Cisco ONS SONET TL1 Command Guide, R6.0
2-52
In automatic mode, the leg to be rolled is automatically dropped upon detection of a valid input
signal on the new path.
In manual mode, the leg to be rolled is retained upon detection of a valid signal on the new path. The
leg must be dropped manually.
Rolling is not allowed on electrical cards or Ethernet cards.
Rolling is not allowed on hairpin circuits.
Rolling is not allowed on monitor circuits.
Rolling is not allowed on any cross-connection that is involved in test access.
Rolling is not allowed on any cross-connection that is involved in cross-connect loopbacks.
Rolling is not allowed on any port that is involved in facility or equipment loopbacks. This
restriction applies to both "roll from" and "roll to."
When rolling on a 1+1 protected circuit, the "roll to" cannot be on the protect port of the protection
group.
Rolling on a BLSR protected circuit cannot violate the rules governing BLSR circuits: a circuit that
traverses a BLSR must use the same STS number on the ring between source and destination.
Rolling on a BLSR protected circuit will be denied if there is an existing protection switch on the
ring. If the protection switch happens after the roll is initiated, the system will not monitor valid
signals on the "roll to" path until the protection switching is cleared.
Rolling on a path protection protected circuit cannot violate the rules governing path protection
circuits: path protection circuits must have one bridge and one selector.
The bridge and selector of a path protection protected circuit cannot be rolled away.
In the case of a dual roll on a path protection protected circuit, both roll points have to be on either
the working or protect path of the circuit. For example, you cannot specify one roll point on the
working path and the other roll point on the protect path of the circuit being rolled.
When rolling on a path protection protected circuit, the "roll to" cannot be line protected (1+1 or
BLSR protected). TL1 can only ensure this on the bridge and selector node, not on the intermediate
node.
Chapter 2 Procedures and Provisioning