Quectel EG25-G and Zscaler

Hello,

I’m running a Zscaler SIM on a Quectel EG25-G with the following firmware:

EG25GGBR07A08M2G_30.200.30.200

I have a strange behavior. The SIM is correctly registering and available signal is > 60%.

However, I cyclically get in ModemManager logs network rejection messages right after the SIM get connected. Sometimes I get the IP address but few seconds after I get rejected. This is the typical behavior:

[modem1] state changed (enabled → registered)
[modem1] simple connect state (6/8): bearer
[modem1] simple connect state (7/8): connect
[modem1] state changed (registered → connecting)
[/dev/cdc-wdm0] Allocating new client ID…
[/dev/cdc-wdm0] Registered ‘wds’ (version 1.67) client with ID ‘18’
[modem1/bearer3] QMI IPv4 Settings:
[modem1/bearer3] address: <xx.xxx.x.x/xx>
[modem1/bearer3] gateway: <xx.xxx.x.xx>
[modem1/bearer3] DNS #1: 8.8.8.8
[modem1/bearer3] DNS #2: 8.8.4.4
[modem1/bearer3] MTU: 1460
[modem1] state changed (connecting → connected)
[modem1] simple connect state (8/8): all done
[modem1] 3GPP registration state changed (roaming → searching)
[modem1] couldn’t load operator code: Current operator MCC/MNC is still unknown
[modem1] couldn’t load operator name: Current operator id is still unknown
[modem1] 3GPP registration state changed (searching → idle)
[modem1] network reject indication received
[modem1] service domain: ps
[modem1] radio interface: lte
[modem1] reject cause: ue-identity-not-derived-by-network
[modem1] 3GPP registration state changed (idle → searching)
[modem1/bearer3] verbose call end reason (3,1110): [cm] (null)
[modem1] state changed (connected → searching)
[modem1/bearer3] connection #1 finished: duration 96s, tx: 1238 bytes, rx: 0 bytes
[modem1] network reject indication received
[modem1] service domain: cs-ps
[modem1] radio interface: lte
[modem1] reject cause: roaming-in-location-area-not-allowed
[modem1] 3GPP registration state changed (searching → idle)
[modem1] state changed (searching → enabled)

is there something which I can try to solve this issue?

Hi Marco,

Here is few steps that you can try on the Zscaler SIM card:

  1. Run AT+CIMI to query IMSI. From IMSI we can check the PLMN (MCC/MNC).

  2. Once you get the PLMN number, you can try to lock PLMN by running command using AT+COPS=1,2,“PLMN Number”,7

  3. Please confirm which LTE Band frequency that supported in your country?

Best regards,
Fazrul Redzuan

Hi Fazrul,
in Italy we supports the following LTE bands:

BAND 28
BAND 20
BAND 8
BAND 32 (only downlink)
BAND 3
BAND 1
BAND 7
BAND 38 (only 1 provider and most of the time used for 5G NR)

I will try to lock PLMN tomorrow and I will report the result.

Many Thanks

Best Regards

Hi Marco,

Sure, really appreciated your updates.

Thanks.

Regards,
Fazrul Redzuan