This table contains the U-interface Performance Monitoring
Thresholds and Alarms for each of the subscriber loops in
the system and for any BRITE cards extending those loops
(e.g. using Subscriber Loop Carrier systems) The table is
indexed first using the Cisco 90 Series channel bank digroup
number, then the channel unit number (1 to 24), then the port
number (0, 1, etc) and finally the location number (the BRITE
card number (1 to 6) or 7 for local parameters in the Cisco
90 Series card). These registers are defined by Bellcore
TR-TSY-000829.