In the LI_PCS_633 to LM_MSO1_LSR01 Microwave link between two RTN950, the LI_PCS_633 displays many AIS alarms and, when a test BER was done, the result reported hi rate of lost of packets.
The NE: LI_PCS_633 only display AIS alarm, the alarm was reported around three times by second. The LM_MSO1_LSR01 was clean of alarm.
Please notice that any equipment displays CES_JTROVR_EXC or CES_JTRUDR_EXC or any alarm related to lost of packets in CSE services.
We noticed the lost of packet packed only by the BER test.
1. A intermittences test were done, and with the spectrum analyzer, any other signal was found, Also the frequency was chance but the result was the same.
2. An inloop was set in NE: LI_PCS_633, but the equipment continue displaying the AIS alarm, and the BER test indicated lost of packets.
3. The IF board were commuted, the problem remain.
4.We required to customer check it the BITS equipments were synchronized, he commented that there was rubidium oscillator between the BITS and the GPS in the side of NE: LI_PCS_633. We required to customer to remove the
rubidium oscillator, after the oscillator were removed, the AIS alarm disappeared and the result of the BER test started to be without lost of packets.
At the beginning we though the BER tester was incorrectly configure, but after to check the handbook all everything was oK.
Then we check that both RTN950 had a external source synchrony, so we needed to now if the BITS equipments were synchronized.
When you have intermittences or lost of packets in the services like CSE, plese check the synchrony scenario. If the equipments has a external sources, be sure that the BITS equipments are synchronized, if the synchrony is provided by
the line, check the quality of the line is OK.