BG600L - TCP Transparent mode failure for large files

we are 2 using different modem types with same higher-level drivers,
BG600L and as 2.nd Source u-Blox SARA-R412.

However, after establishing the TCP transparent connection the BG600L seems to have problems with the HTTP-Reply of the Server via TCP, where the SARA-R412 works fine and exactly as the RFCs:

A reply to a HTTP-Request from our server starts like that:

HTTP/1.1 200 OK
Date: Sun, 07 Aug 2022 13:38:57 GMT
Server: Apache/2.4.54 (Unix)
X-Powered-By: PHP/8.0.20
Content-Type: text/plain;charset=UTF-8
Connection: close
Transfer-Encoding: chunked

[chunks + data(s)]

The BG600L (with latest Firmware BG600LM3LAR02A04) sends a “Connection Closed” a few bytes before all data has been retrieved. E.g. for a 100kB-File the last chunk of e.g. 5k is lost.
Also, if using HTTP1.0 requests, the last few kB of the data are missing.
With “small” data (e.g <10kB) all works fine. (HW-Flow Control is enabled).

Any ideas? Thanks,

Hi Jo,

This is caused by cache,datas were cached and this issue was fixed.
and the firmware will be official release in the next weeks.

Linkin WANG

Hello Linkin,
thanks! So I’ll wait… We previously used DFOTA to upgrade existing systems. However: DFOTA seems only to work via HTTP and LTE-M (not HTTPS or 2G) for the BG600L. Since here in Europe we still have a lot places with only 2G, it would be fine if DFOTA works with 2G too…
Best regards, Jo

Hi Jo,

Yes, BG600L series module are not support 2G, only support CAT-M &NBIoT network.
If for testing only, you can try upgrade fw with local FOTA.

Hi Jo,
If possible, could you share us some logs for this TCP issue?
Just want double check if the same with which we fixed .

Hi Linkin,
Yes, a flexible Content-Generator (PHP / C) is on my server: Media-Browser
You can test it with HTTP/1.0 and /1.1 and the content depends on the server (chunked, plain, …).
However: The BG600L looses packes for larger content (e.g. >100k).
Best regards, Jo

BTW about DFOTA Download: the BG600L SHOULD work with 2G and LTE-M :wink: