The document discusses the architecture of a communication system using XMPP protocol for messaging, focusing on features like multi-chat and secure audio channels. It mentions various components such as ejabberd server, STUN server, and firewall configurations. The communication is encrypted using DTLS and TLS 1.2 to ensure secure data transmission between clients.

1. iOS ANDROID

5. Client Server
eJabberd
MultiChat
STUN server
DTLS
Encrypted Audio Channel (SRTP)
Firewall
Firewall
Caller 1 Caller 2

7. eJabberd 2
server
Application
Sender
Message
through
XMPP protocol
TLS 1.2
communication
channel
Message through
XMPP protocol
TLS 1.2 communication
RecipientRecipient
Message through
XMPP protocol
channel
TLS 1.2 communication
channel

10. Viber Skype MultiChat

12. MultiChat