Issue with Asterisk 16.30 on Ubuntu 20.04 x86-64: Chan_quectel causing device status to get stuck in dialing state

[johnshuxian]

Description:
I am experiencing an issue with Asterisk 16.30 on Ubuntu 20.04 x86-64 when using chan_quectel to connect multiple EC20 devices. After normal polling and dialing for a certain period, some devices' status occasionally gets stuck in the "dialing" state and fails to release, even though the devices are actually idle. Manually issuing quectel restart now deviceX resolves the problem temporarily, but the issue reoccurs frequently.

Steps to Reproduce:

Set up Asterisk 16.30 on Ubuntu 20.04 x86-64.
Connect multiple EC20 devices using chan_quectel.
Perform regular polling and dialing operations.
Expected Behavior:
Devices should return to an idle state after completing a call and be available for the next call.

Actual Behavior:
Some devices' status gets stuck in the "dialing" state and does not release even when the devices are idle.

Additional Information:

Asterisk Version: 16.30
Operating System: Ubuntu 20.04 x86-64

Please let me know if anyone has encountered a similar problem or if there are any suggestions for resolving this issue. Your assistance is greatly appreciated.

[johnshuxian]

this is my quectel.conf

[general]

interval=15			; Number of seconds between trying to connect to devices
smsdb=/var/lib/asterisk/smsdb
csmsttl=600

;------------------------------ JITTER BUFFER CONFIGURATION --------------------------
;jbenable = yes			; Enables the use of a jitterbuffer on the receiving side of a
				; Quectel channel. Defaults to "no". An enabled jitterbuffer will
				; be used only if the sending side can create and the receiving
				; side can not accept jitter. The Quectel channel can't accept jitter,
				; thus an enabled jitterbuffer on the receive Quectel side will always
				; be used if the sending side can create jitter.

;jbforce = no			; Forces the use of a jitterbuffer on the receive side of a Quectel
				; channel. Defaults to "no".

;jbmaxsize = 200		; Max length of the jitterbuffer in milliseconds.

;jbresyncthreshold = 1000	; Jump in the frame timestamps over which the jitterbuffer is
				; resynchronized. Useful to improve the quality of the voice, with
				; big jumps in/broken timestamps, usually sent from exotic devices
				; and programs. Defaults to 1000.

;jbimpl = fixed			; Jitterbuffer implementation, used on the receiving side of a Quectel
				; channel. Two implementations are currently available - "fixed"
				; (with size always equals to jbmaxsize) and "adaptive" (with
				; variable size, actually the new jb of IAX2). Defaults to fixed.

;jbtargetextra = 40		; This option only affects the jb when 'jbimpl = adaptive' is set.
				; The option represents the number of milliseconds by which the new jitter buffer
				; will pad its size. the default is 40, so without modification, the new
				; jitter buffer will set its size to the jitter value plus 40 milliseconds.
				; increasing this value may help if your network normally has low jitter,
				; but occasionally has spikes.

;jblog = no			; Enables jitterbuffer frame logging. Defaults to "no".
;-----------------------------------------------------------------------------------

[defaults]
; now you can set here any not required device settings as template
;   sure you can overwrite in any [device] section this default values

context=incoming-mobile		; context for incoming calls
group=0				; calling group
rxgain=0			; increase the incoming volume; may be negative
txgain=0			; increase the outgoint volume; may be negative
autodeletesms=yes		; auto delete incoming sms
resetquectel=yes			; reset quectel during initialization with ATZ command
u2diag=-1			; set ^U2DIAG parameter on device (0 = disable everything except modem function) ; -1 not use ^U2DIAG command
usecallingpres=yes		; use the caller ID presentation or not
callingpres=allowed_passed_screen ; set caller ID presentation		by default use default network settings
disablesms=no			; disable of SMS reading from device when received
				;  chan_quectel has currently a bug with SMS reception. When a SMS gets in during a
				;  call chan_quectel might crash. Enable this option to disable sms reception.
				;  default = no

exten=70

language=en			; set channel default language
mindtmfgap=45			; minimal interval from end of previews DTMF from begining of next in ms
mindtmfduration=80		; minimal DTMF tone duration in ms
mindtmfinterval=200		; minimal interval between ends of DTMF of same digits in ms

callwaiting=auto		; if 'yes' allow incoming calls waiting; by default use network settings
				; if 'no' waiting calls just ignored
disable=no			; OBSOLETED by initstate: if 'yes' no load this device and just ignore this section

initstate=start	        ; specified initial state of device, must be one of 'stop' 'start' 'remote'
				;   'remove' same as 'disable=yes'
				;  default is 'relax' by compatibility reason

; quectel required settings
;[quectel0]
;audio=/dev/ttyUSB1		         ; tty port for Audio, set as ttyUSB4 for Simcom if no other dev present
;data=/dev/ttyUSB2		         ; tty port for AT commands; 		no default value
;quec_uac=1                              ; Uncomment line if using UAC mode
;alsadev=hw:CARD=Android,DEV=0           ; Uncomment if using UAC, set device name or index as reqd

; discovered device
[d0001]
imei=866824065769024

[d0002]
imei=110000615034930

[d0003]
imei=864568060080042

[d0004]
imei=864568060123529

[d0005]
imei=864568060122620

[d0006]
imei=864568060123925

[d0007]
imei=864568060081560

[d0008]
imei=864568060080141

[d0009]
imei=864568060123859

[d0010]
imei=864568060073914

[d0011]
imei=864568060081677

[d0012]
imei=864568060122331