5-12
MAX Administration Guide
Administering E1 and T1 Services
Using Net/E1 and Net/T1 status windows
Fractional T1 services
Set the Call Type parameter to specify several fractional T1 settings. One of the settings,
FT1-B&O, affects the information that the MAX unit displays in the Statistics window.
Fractional T1 is a nailed-up T1 line with bandwidth that might be only a fraction of the full T1
bandwidth. A nailed-up line is one that is rented from the telephone company for exclusive
use, 24 hours per day, seven days per week. It is possible to lease one channel on a line from
the telephone company for exclusive use, 24 hours per day, seven days per week. The
connection exists between two predetermined points and cannot be switched to other locations.
A nailed-up line is also called a leased line.
Fractional T1-Backup and Overflow (FT1-B&O) is a type of call that provides automatic
protection of nailed-up circuits. For FT1-B&O calls, the second line of the Statistics window
might not show the call duration. When an FT1-B&O call has no bad channels, the call
duration appears as usual. But if it does, the number of offline nailed-up channels appears after
the call quality. The following screen shows the Statistics window of an FT1-B&O call with
two channels offline:
21-300 Alb O
Qual Good 00:04:01
ES
Specifies errored seconds. For ESF lines, this register displays the
number of seconds in the 15-minute period in which there was at
least one error event, or in which two or more framing errors were
detected within a 3 ms interval. For D4 lines, this register displays
the number of seconds in which one or more framing bit errors (FE)
were detected or in which a controlled slip (CS) occurred.
US
Indicates unavailable seconds—the number of seconds in the
15-minute period preceded by at least 10 consecutive severely
errored seconds (SS).
SS
Displays severely errored seconds—the number of seconds, during
the 15-minute period, in which there were at least 320 CRC-6 errors
as detected by the MAX unit, or in which the T1 line was out of
frame. For D4 lines, this register displays the number of one-second
intervals containing eight or more framing bit errors (FEs) or one or
more SEFs.
BS
Specifies bursty errored seconds—the number of seconds, during the
15-minute period, in which there were at least 2, but not more than
319, CRC-6 errors as detected by the MAX unit.
LF
Indicates loss of frame seconds— the number of seconds in the
15-minute period in which the T1 line was out of frame.
CS
Displays controlled slip seconds—the number of seconds in the
15-minute period in which a frame was either replicated or deleted.
Table 5-5. FDL performance registers (continued)
Register name
Description