XMPP vs WebSocket - Which to use for applications?

XMPP - All About the Protocol

Used for XML fragment exchange b/w the server-client duo, XMPP is one of the early open-standard protocols concerning communication. It has a long history of over 20 years. Its effective implementation demands the mandatory use of suitable transport binding. 

In the OSI model, XMPP mainly functions on the application layer which elaborates the structural pattern XML (of its parts or syntax). For transmission/relaying, it needs transport layers’ protocols’ (HTTP or TCP) help. 

eXtensible Messaging & Presence Protocol, mostly, is used in developments that involve chat applications, applications with facilities like voice/video calling, instant sending of text/rich-media, and multi-part video calling.

Pros 

With XMPP, you have multiple benefits to enjoy while you are developing an IM app. For instance:

• Its cybersecurity features are advanced enough to keep leading digital world dangers at bay.
• The decentralized architecture ensures that it is accessible to all.
• The technical support offered is reliable and effective.
• It is flexible and lets end-users make changes in the data transmission process as per the need of the project.
• It helps in establishing a persistent (continual) connection.
• It simplifies communication b/w servers by enabling diverse architectures to transmit data.
• It reacts immediately towards the presence of the end-user. Hence, you’ll be able to find out whether the end-user is online or offline.

Cons

Even if XMPP renders multiple benefits, it is not flawless. There are certain obvious drawbacks or cons of this protocol.

• It lacks a QoS mechanism
• The text-based XML streaming or communication increases the operational overheads
• The content transportation often takes place without any sync 
• At times, presence and/or instant messages can cause server overload

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WebSocket - All About the Protocol

It’s a modern-era IM protocol, permitting binary & text data’s to-and-fro flow for server-client in any persistent channel.

It’s bidirectional, full-duplex, and stateful in nature. It’s mainly used for a mobile app that needs an ongoing connection. It has nothing to do with defining the nature and type of data-in-transit. It needs the support of other protocols to fully implement the IM ability in the chat app.

Pros

WebSocket is designed to fill the gap that HTTP –based technology created in data transmission. Over time, it was observed that it was more than this. Have a look at key benefits to enjoy with WebSockets.

• It keeps communication on unless the server or client stops it 
• There is hardly any match to WebSocket when it comes to speed. It can transmit data faster than AJAX and HTTP
• It can make data transmission between the origin servers possible
• It is compatible with multiple kinds of platforms such as mobile, web, and desktop
• Using WebSockets is cost-effective as it only exerts 2-byte expenses
• It effectively fixes the long polling issue

Cons

Despite the benefits, WebSocket has some potential drawbacks that are worth noting. For instance:

• It only works when you have got a fully HTML 5 compliant browser
• It lacks AJAX- like success mechanism 
• No intermediary or edge is caching possible 
• When WebSocket is in action, developers will have a tough time implementing even the most simple HTTP statuses 

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Comparison of protocols

After having a deeper understanding of the basic meaning of these two protocols, it’s time to move on to a detailed XMPP v/s WebSocket comparison. We hand-picked a few most concerning aspects and then compared the offerings of these two. 

1. Security

A brief security assessment of these two protocols is crucial as using an unsecured protocol will put everything at risk. XMPP is a time-seasoned protocol and has gone through multiple changes and improvements all through these activation years. As the security requirements change, the protocol improves its security front. It comes with various security layers and features. 

When XMPP is activated, personal identity is compulsory. Both the messages and hosts have to be authenticated before being a part of communication to avoid spoofing risk. Even though it was enough to keep spam threats under control, 

XMPP even permits end-users to add security layers as per the need of the hour. 

When it comes to encryption, XMPP offers two types. The first encryption comes into being when a connection establishes and its authentication begins. This encryption completes with SASL. Once the connection is successfully built, client-server communication is then backed by TLS encryption.

If WebSocket’s security offering is examined carefully, you will be able to learn that it needs a bit of improvement. It’s a very young protocol and requires more improvement and upgrades to match what XMPP is offering. But, it doesn’t mean it lacks security. It offers encryption strong enough to keep any malicious intrusion at bay. 

2. Operational architecture

The core operational architecture of XMPP is decentralized, while WebSockets follows a centralized architecture. XMPP is based on the client-server model and prevents direct interaction between clients. WebSockets take the help of APIs and ensure the client and server are communicating continuously.

3. Compatibility with other protocols

XMPP is a primitive protocol and lacks API compatibility. On the other hand, WebSocket is highly API optimized, which is the core of better compatibility with other protocols.

4. ‍Sending and receiving binary data

In WebSockets, communication involves using codes and messages, setting users free from the troubles of parsing and buffering issues. This makes data transfer quick. XMPP follows a very thin path for binary data transfer, which makes everything cumbersome.

5. ‍Extensibility

WebSocket deals with the transport layer’s extensibility, while XMPP is concerned with the application layer’s extensibility. It’s possible to add more than 40 protocols over WebSockets. But, XMPP isn’t that flexible.

6. ‍Speed

Even though both are useful to transmit data in real-time at blazing speed, WebSocket outperforms XMPP on this front because of its centralized nature and continual communication. XMPP force authentication and authorization of both the server and the client slows down its performance a bit.

Examples of using XMPP and WebSocket

XMPP is used in WhatsApp, GTalk, and Grindr applications and inbuilt in the chat features. To be specific, the protocol is mostly preferred where one-to-one secure or group-based communication is the main feature of the app.

Trello, Slack, and Discord are the three most famous apps built using WebSockets. As we know, these applications are for teams and remote workers. To conclude, the protocol is more useful for confined virtual workspaces as it uses continual connection.

Conclusion - Which protocol to use?

WebSocket and XMPP - both are designed for instant messaging. However, which one you should pick is a question that should be answered after taking project requirements into context. As far as our understanding goes, we recommend using WebSockets when lots of data have to be transferred, and communication should remain open.

XMPP is the best choice to make when development requires tons of plugins and security has to be top-notch. So, before you make a choice between these two, you need to find out what exactly your development goals are. Work it out beforehand, and then pick a protocol accordingly. However, one thing is sure both will deliver at par performance if used correctly.