root@small-apps-tel:/opt/sipsystem# systemctl status sipsystem.service
● sipsystem.service - SipSystem Daemon
   Loaded: loaded (/etc/systemd/system/sipsystem.service; enabled; vendor preset: enabled)
   Active: active (running) since Wed 2021-08-04 00:00:51 UTC; 4h 21min ago
 Main PID: 684 (java)
    Tasks: 34 (limit: 4915)
   Memory: 470.6M
      CPU: 1min 9.233s
   CGroup: /system.slice/sipsystem.service
           └─684 /usr/bin/java -Xmx1700m -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/opt/sipsystem -Djava.net.preferIPv4Stack=true -jar /opt/sipsystem/sip-system-impl.jar

Aug 04 04:22:12 small-apps-tel java[684]: 2021-08-04 04:22:12.889  WARN 684 --- [l-9387-thread-3] o.j.n.c.SimpleChannelUpstreamHandler     : EXCEPTION, please implement tech.ivoice.freeswitch.esl.inbound.inbound
Aug 04 04:22:12 small-apps-tel java[684]: java.net.ConnectException: Connection refused
Aug 04 04:22:12 small-apps-tel java[684]:         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) ~[na:1.8.0_292]
Aug 04 04:22:12 small-apps-tel java[684]:         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:716) ~[na:1.8.0_292]
Aug 04 04:22:12 small-apps-tel java[684]:         at org.jboss.netty.channel.socket.nio.NioClientSocketPipelineSink$Boss.connect(NioClientSocketPipelineSink.java:401) ~[netty-3.2.10.Final.jar!/:3.2.10.Final]
Aug 04 04:22:12 small-apps-tel java[684]:         at org.jboss.netty.channel.socket.nio.NioClientSocketPipelineSink$Boss.processSelectedKeys(NioClientSocketPipelineSink.java:370) ~[netty-3.2.10.Final.jar!/:3.2.1
Aug 04 04:22:12 small-apps-tel java[684]:         at org.jboss.netty.channel.socket.nio.NioClientSocketPipelineSink$Boss.run(NioClientSocketPipelineSink.java:292) ~[netty-3.2.10.Final.jar!/:3.2.10.Final]
Aug 04 04:22:12 small-apps-tel java[684]:         at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_292]
Aug 04 04:22:12 small-apps-tel java[684]:         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_292]
Aug 04 04:22:12 small-apps-tel java[684]:         at java.lang.Thread.run(Thread.java:748) [na:1.8.0_292]