I have Gsm Modem 8 ports that use quectel E25-E8, when I send some sms to a port like 200-300 it blocks and for 15-20 minutes not receive any at commands but continue lamping, how can I resolve?
Hello @Youssef_Gad Welcome to the Quectel Forum. It’s nice to have you here.
As your problem is something quite specific, I can recommend you to send an email to Quectel Support team, is: support@quectel.com - I can guarantee you that you’ll receive the proper assistance over there.
Not less important, if you can provide more details and logs, they will faster help you out in a great solution.
Unfortunately, I can’t give you any specific information about your problem with your device, forgive me for that.
A good “double check” about checking the hardware and having the latest drivers for your device is a great step to start…
If you want, my drivers and tools are relatively updated, and I can share with you.
here: EP06.zip - Google ドライブ
Please do not use the firmwares that is in my repository, since they are for my device (EP06-E).
Documentations, tools and drivers are common between our devices.
As a second suggestion, if you need an updated / latest firmware, please contact @herbert.pan-Q and I am quite sure that he will gladly assist you.
Have a nice Saturday (02-dec-2023) 
Hi @Youssef_Gad
I don’t quite understand your question. Are you saying that sending SMS messages will crash?