Ring a SIP phone using pjsip

ring.sh

#!/usr/bin/env bash

target_number="$1"

user="<sip_user>"
password="<sip_password>"
registrar="fritz.box"
sound_file="/path/to/sound_file.wav"
duration=20 #in seconds
                                                                                                                                                                       
( sleep $duration; echo q ) \   
| pjsua \   
    --id "sip:$user@$registrar" \   
    --registrar "sip:$registrar;transport=tcp" \   
    --realm "$registrar" \   
    --username "$user" \   
    --password "$password" \   
    --local-port 5061 \   
    --null-audio \   
    --auto-play --play-file "$sound_file" \   
    "sip:$target_number@$registrar"