Specifications

Chapter 6 Troubleshooting and Diagnostics Installation and Operation Manual
6-18 Monitoring IPmux-8/16 Performance IPmux-8/16 Ver. 6.00
Table 6-6. Bundle Connection Status Parameters (Cont.)
Parameter Description
Jitter Buffer
Overflows
The number of times an overflow situation took place.
Explanation:
In steady state, the jitter buffer is filled up to its middle point, which means it has the space to hold an
additional similar quantity of packets. Overflow is opposite phenomenon of the underflow, i.e., when
a big burst of packets reaches the IPmux (a burst with more packets than the jitter buffer can store),
the buffer will be filled up to its top. In this case, an unknown number of excessive packets are
dropped and hence IPmux initiates a forced underflow by flashing (emptying) the buffer in order to
start fresh from the beginning. An overflow situation always results in an immediate underflow, forced
by the IPmux. After the buffer is flashed, the process of filling up the buffer is started again, as
explained above (“Underflow” section).
An overflow situation can be a cause of:
• A big burst of packets, filling up the buffer completely. The Burst itself can often be a cause of
some element along the IP network queuing the packets and then transmitting them all at once.
• Too small jitter buffer configuration.
When system is not locked on the same clock, it will lead to a situation in which data is clocked out of
the jitter buffer at a rate different from the one it is clocked into. This will gradually result in either an
overflow or underflow event, depending on which rate is higher. The event will repeat itself
periodically as long as the system clock is not locked.
Recommendations:
• Check network devices and try increasing Jitter Buffer configuration.
• Check system’s clocking configuration
• Make sure the same amount of timeslots for bundle is configured on each side of the IPmux
application, and that the “TDM bytes in frame” parameter is identical in both IPmux units.
Redundancy Flips Number of occurred bundle redundancy flips
Configuring Intervals for Bundle Statistics Collection
You can set the interval for the bundle statistics collection, as well the statistics
threshold. The intervals can be set for the following bundle events:
• JIT BUF UFLOWS
• JIT BUF OFLOWS
• SN ERRORS.
Path: Main > System > Event Log > Update Bundle Connection Events or Bundle
Connection Events Threshold.

To configure intervals for bundle statistic collection:
• From the Event Log menu, configure the following:
 Update bundle connection events: 1 sec, 1 min
 Bundle connection events threshold (a number of events that cause the
alarm to be initiated): 1–100.
With the interval set to 1 minute, a new START event (such as SN ERRORS
START SLOT1 PORT1 BNDL1) is stored in the event log if the number of
errors has been above threshold during the last minute.