Step-1:

In this case, we need to review the /var/log/versa/versa-usbmodem.log, If we have a tentative timeframe of the issue, we should be able to review this log for the same timeframe. 

Step-2:  

admin@versa-flexvnf-cli> show interfaces wwan status carrier-brief vni-0/101 

state              registered 

registration-state registered 

iccid              8901260185774107424 

imsi               310260187410742 

number             15108273716 

current_tech       lte 

signal             52 

rssi               "-81.00 dBm" 

rsrq               "-7.00 dB" 

rsrp               "-108.00 dBm" 

snr                "11.60 dB" 

operator-id        310260 

operator-name      T-Mobile 

apn                "" 

address            26.239.20.152 

prefix             28 

gateway            26.239.20.153 

dns                10.177.0.210 

uptime             91200 

rx-bytes           881901 

tx-bytes           4068452 

Please make sure that all 4 below Signal parameters are in the Good range. Even if one Signal parameter is in a poor state, the connectivity issue or packet loss may be seen. 

RSRP    Signal Strength    Color in Director and Analytics    Description 

≥ –80 dBm    Excellent    Green    Strong signal with maximum data speeds 

–80 dBm to –90 dBm    Good    Yellow    Strong signal with good data speeds 

–90 dBm to –100 dBm    Fair to poor    Orange    Reliable data speeds may be attained, but marginal data with drop-outs is possible. As this value approaches –100 dBm, performance will drop drastically. 

≤ –100 dBm    No signal    Red    Disconnection. 

RSRQ    Signal Strength    Color in Director and Analytics    Description 

≥ –10 dB    Excellent    Green    Strong signal with maximum data speeds 

–10 dB to –15 dB    Good    Yellow    Strong signal with good data speeds 

–15 dB to –20 dB    Fair to poor    Orange    Reliable data speeds may be attained, but marginal data with drop-outs is possible. As this value approaches –20 dB, performance will drop drastically. 

≤ –20 dB    No signal    Red    Disconnection. 

RSSI    Signal Strength    Color in Director and Analytics    Description 

≥ –65 dBm    Excellent    Green    Strong signal with maximum data speeds 

–65 dBm to –75 dBm    Good    Yellow    Strong signal with good data speeds 

–75 dBm to –85 dBm    Fair    Orange    Fair but useful, fast, and reliable data speeds may be attained, but marginal data with dropouts is possible. 

–85 dBm to –95 dBm    Poor    Orange    Performance will drop drastically. 

≤ –95 dBm    No signal    Red    Disconnection. 

SINR    Signal Strength    Color in Director and Analytics    Description 

≥ 20 dB    Excellent    Green    Strong signal with maximum data speeds 

0 dB to 13 dB    Fair to poor    Orange    Reliable data speeds may be attained, but marginal data with drop-outs is possible. As this value approaches 0, performance will drop drastically. 

≤ 0 dB    No signal    Red    Disconnection. 

13 dB to 20 dB    Good    Yellow    Strong signal with good data speeds