LTE2566-M634 Firmware bugs and workaround

Angelina Posts: 7
First Comment
edited January 4 in Mobile Broadband

More firmware bugs:
APN Auto not working in Italy
Authentication Auto not working
Network Type Auto not working, will connect only to 3G at band 8 (900MHz) and only with manually set APN and PAP. else no connection.
Band Selection Auto not working, if per random connected to 4G will disconnect after random time between 1 second and 20 minutes and temporarily banned (not allowed to reconnect until pwer down for at least some minutes).
My solution/workaraound so far to use this thing in Italy:
APN manual, set correctly for provider
Authentication PAP
Network Type 4G
Band Selection manual
Band List allow only 1, 3, 7, 8, 20 for all but not for Iliad, 38 only for WindTre but not for others, 28 only for TIM Vodafone Iliad but not for WindTre
Managemet » TR069 Enable » Inform Enable, leave rest at defaults or empty
This way I get a consistent connection with a steady public IP. The LTE2566 constantly changes bands, but connection stays, but has throughput dropouts while switching over. Without enabling TR069, connection drops at random time, device temporarily banned.
If enabled band 41, no other FDD bands will work, so must disable in Italy. (Maybe the 2MHz shift bug?)
If enabled a band not used by SIM provider, connection may not establish at all. The effect is random. Surely will disconnect one random time and be temporarily banned.
Similar procedure may apply for all users and roaming in Europe and elsewhere, except maybe Russia and Türkiye (it's obviously a product for Russian and Turkish market).
Speed is only good at TDD, scraping at theoretical maximum. The rest, even 4G+, is neither better nor faster than a 20buck China CAT4, even at 50m distance from BTS, due to the constant band tripping. A bit sad. Looks like the firmware needs a serious overhaul.


All Replies

  • Angelina
    Angelina Posts: 7
    First Comment

    PS: Band 8 should be disabled, if you don't want to risk a fallback to 3G even when Network Type is set manually to 4G

  • Angelina
    Angelina Posts: 7
    First Comment

    PPS: The current firmware used while discovering the issues depicted in OP is Version: V1.00(ABTW.3)C0
    Which seems to be the most recent available now (2023-03-24) for the LTE2566-M634.

  • Bob_C
    Bob_C Posts: 165  Zyxel Employee
    First Anniversary 10 Comments Friend Collector First Answer

    Hi Angelina,

    Thanks very much for the input. If you have found out the corresponding APNs for Italian service providers, could you please share them?



  • Angelina
    Angelina Posts: 7
    First Comment

    This are APN for some Italian networks:







  • Angelina
    Angelina Posts: 7
    First Comment

    With WindTre I tested the thoughput at MTU sizes different from the default 1500.

    At MTU size 1420 the speed instantly doubled with WindTre when connected to the same bands. Dropouts from CA are fewer. Device still get "promoted" to TDD, but this time can also change back to FDD and CA, which it does not do when 1500 is set. Strange, anyway, and I don't get if this is just a coincidence or actually an underlying defect in the firmware.

    Hard to undertstand why there is no AUTO option, as the MTU is normally communicated by the network at connection time and even if faulty APN AUTO or Authentication AUTO are worked around, the MTU could still be determined by the network, instead of being hardcoded.

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