Agent screen's phone icon showing error

Server Setup Information

  • Version of Rocket.Chat Server: Rocket.Chat 4.6.0
  • Operating System: Oracle Linux 8.5
  • Deployment Method: Self Hosted from tar (cdn-download.rocket.chat/build/rocket.chat-4.6.0.tgz)
  • Number of Running Instances: 1
  • DB Replicaset Oplog: rs01
  • NodeJS Version: 14.18.3
  • MongoDB Version: 4.4.13
  • Proxy: Apache httpd 2.4.46
  • Firewalls involved: NA
  • Asterisk: Asterisk 18.10.1

Description

I have turned on and configured both Asterisk and Rocket.Chat VoIP.
However, when a agent logged into Rocket.Chat, the phone icon is showing error.
May I know what is that means ?
I checked both Asterisk log and Rocket.Chat log (I have turn on Errors, Information and Debug), but I dont see any errors at all.
Hence, I wish to know the phone icon error what is that means, and how I can further investigate, or actually this function is not ready yet ?

Asterisk manager.conf:

[general]
enabled = yes
port = 5038
bindaddr = 0.0.0.0

[rocketchat]
secret=Admin123
permit=0.0.0.0/0.0.0.0
read=all
write=all

Asterisk http.conf:

[general]
servername=Asterisk
enabled=yes
bindaddr=0.0.0.0

[rocketchat]
type=user
read_only=no
password=Admin123

Configuration in Management Server section:

Server Host: 192.168.1.11
Server Port: 5038
Server Name: Asterisk
Username: rocketchat
Password: Admin123

Configuration in Server Configuration section:

Server Host: 192.168.1.11
Websocket Port: 8088
Server Name: Asterisk
Websocket Path: /ws