Nortel DMS-100 Series Maintenance Manual page 104

1-88 Maintenance overview
Scenarios of manual protection link release
Scenario 1
The C-shelf is protection switched because of a defective C-link. The
protection link is INSV.
Scenario 2
The C-shelf is manually protection switched. Faults are not present on any
primary link. The protection link is INSV.
Scenario 3
The C-shelf is manually protection switched. A fault is present on the
B-link. The B-link is system busy. Faults are not present on the A-, C- or
D-links. The protection link is INSV.
Enabling and disabling protection switching
Users can disable protection switching for any primary link. Operating
company personnel can attempt to disable protection switching for a link
that is automatically or manually protection switched. The system prompts
personnel with a message that indicates the link is protection switched. The
system prompts users with a question that asks if they want to continue. If
the users want to continue, the link is disabled for protection switching and
the protection link is released. Refer to scenarios 1, 2 and 3.
If a disabled primary link is defective and protection switching for the link is
enabled, an automatic protection switch is attempted. Follow the rules
described in "Automatic protection switching for InSv, SysB, ManB, and
PBsy primary DS-1 links" on page 1-76 to attempt an automatic protection
switch.
Protection switching is initially enabled for all primary links with the
addition of a protection link to the RCS.
297-8231-550 Standard 09.01 August 1998
You manually release the protection link.
The protection link is immediately switched back to the C-shelf.
Manually release the protection link.
The protection link remains released until an automatic or a manual
protection switch is performed.
Manually release the protection link.
The protection link is switched for the B-link.
The B-link returned to service.