Specifications

IPmux-11 Installation and Operation Manual Chapter 4 Diagnostics and Troubleshooting
Performance Monitoring Statistics 4-7
Monitoring>Statistics>Physical layer (E1)
Channel ID (1)
LOS: (0) DM: (0)
LOF (Red): (0) ES: (0)
LCV: (0) SES: (0)
RAI (Yellow): (0) UAS: (0)
AIS: (0) LOMF: (0)
FEBE: (0)
BES: (0)
Time Since (sec): (366) Valid Intervals: (96)
1. Interval ... (0)
Figure 4-7. E1/T1 Statistics
Table 4-2 describes the E1/T1 statistics.
Table 4-2. E1/T1 Statistics
Alarm Description
LOS A Loss of Signal indicates that there is either no signal arriving from the adjacent E1/T1 device or no
valid E1 voltage mask or no voltage alteration between positive and negative amplitudes.
For E1 links, the LOS counter will increase by one for each second during which a consecutive
255 pulses have no pulse of negative or positive polarity.
For T1 links, the LOS counter will increase by one for each second during which a consecutive
192 pulses have no pulse of negative or positive polarity.
A LOS alarm is also indicated by the front panel E1/T1 SYNC LED (red). The green E1/T1 SYNC LED
indicates that the E1/T1 synchronization has been restored).
Recommendations:
Check the physical layer (connectors, cables, etc.)
LOF (Red) A Loss of Frame indicates that the IPmux-11 lost E1/T1 synch opposite its adjacent E1/T1 device.
In more detail, this is a period of 2.5 seconds for T1 or 100 msec for E1, during which an OOF (Out Of
Frame) error persisted and no AIS errors were detected.
For E1 links an OOF defect is declared when three consecutive frame alignment signals have been
received with an error.
For T1 links, an OOF defect is declared when the receiver detects two or more framing errors within a
three msec period for ESF signals and 0.75 msec for D4 signals, or two or more errors out of five or
fewer consecutive framing-bits.
A LOF alarm is also indicated by the front panel E1/T1 SYNC LED (red).
When the IPmux enters a red alarm condition, it sends an Yf bit (yellow alarm or RAI) towards the
adjacent E1/T1 device.
Recommendations:
Check all framing related parameters for E1/T1, and physical connections.