XMPP Protocol: Advantages and Disadvantages

This page explores the advantages and disadvantages of the XMPP protocol, commonly used in IoT (Internet of Things) applications.

What is XMPP Protocol?

Introduction: XMPP stands for Extensible Messaging and Presence Protocol. It’s a client-server architecture where an XMPP client communicates with an XMPP server using a TCP socket. It can also function over HTTP using a websocket implementation.

XMPP is an open protocol that streams XML elements to exchange messages in real time. Being asynchronous and XML-based, the protocol is defined in RFCs like RFC2778 and RFC2779 (general model for presence and instant messaging), RFC3920 (XMPP core), and RFC3921 (XMPP instant messaging).

XMPP’s features, including addressing, scalability, federation, and security, make it well-suited for IoT applications. It also uses a publish/subscribe mechanism for data sharing, similar to the MQTT protocol.

XMPP Client vs XMPP Server

The figure above shows a simplified XMPP architecture. It uses port 5222 for client-to-server communication and port 5269 for server-to-server communication.

XMPP is utilized in various applications, including:

• Instant messaging apps (e.g., Google Talk, WhatsApp)
• Presence status
• Message delivery
• Conferencing (multi-party chat)
• Roster management
• Voice and video calls
• Online gaming
• News websites
• VoIP apps

Benefits of XMPP Protocol

The following are the benefits of using XMPP:

• Extensible: Customizable to individual user requirements.
• Messaging: Relies on short messages for quick communication between user and server.
• Presence: Reacts to the user’s presence and status.
• Open Protocol: An open platform that is constantly evolving.
• Secured: Uses TLS and SASL to provide a secure, end-to-end connection.
• Persistent Connection: Offers a persistent connection.
• Decentralized: No central XMPP servers are required.
• Interoperable: Allows servers with different architectures to communicate.

Drawbacks of XMPP Protocol

The following are the drawbacks of using XMPP:

• No QoS: Lacks a Quality of Service (QoS) mechanism like the one used in MQTT.
• XML Overhead: Streaming XML has overhead due to its text-based communication compared to binary-based communication.
• Asynchronous XML: XML content is transported asynchronously.
• Server Overload: The server can be overloaded with presence and instant messaging traffic.