Operating system name and version: Debian 10
Version of smsd: 3.1.21
Smsd installed from: package repository
Name and model of a modem / phone: Novatel USB620L
Interface: USB

This modem can send text, but I was having the "registration denied" issue so I had to turn off "check_network" in /etc/smsd.conf:

check_network = 0

Receiving does not work. When you send a text message to the modem and monitor the modem using minicom:

$QCMTI: "ME",0

To me, this means a message was received into memory location zero. The FAQ states these cannot be read. I tried several AT commands (via minicom) to direct the messages to the SIM. All the AT commands responded with "OK", but the messages always seem to arrive via memory.

The log also seems to show the modem is in SIM mode for receiving:

2020-10-01 09:07:21,7, GSM1: <- +CPMS: "SM",0,0,"SM",0,0,"SM",0,0 OK

Otherwise, the modem has been working well.

I signed up for this forum for issues with this very modem, lord knows I searched high and low on the web...

I'm running stretch instead of buster. I REALLY wanted to use smsd. I actually downloaded the source and re-compiled with all the debugging turned on. I could not get the darn thing to send a text. Running direct against the modem (I use ckermit) I found I could not send a message until I sent +CGSMS=2. I ended up writing a script to send sms via the device, and try as I might I could not receive a message. I have the PDF for the U620L command set. I tried most everything. Anyone else had any luck. I *know* you can do it, because the VZ software will do it on Windows.

. . .
[GSM1]
init = ATE0+CPMS="SM","SM","SM"+CGSMS=2
device = /dev/ttyUSB0
baudrate = 9600
incoming = yes
check_memory_method = 2
check_network = 0
memory_start = 0