Difference Between SIP and XMPP

Today, there is development in every field. From science to medicines, nothing is left behind.

In this era where most of the things are done on the internet, communications are also developed day by day to ensure there is no gap, and people get connected.

Many communication protocols are used, and SIP and XMPP are two of them that are widely used. They are very similar and used for voice calls and messaging but have differences in how the messages are communicated.

SIP vs XMPP

The difference between SIP and XMPP is that they both are used as communication protocols, but their intended purpose is different and also the way the communications happen. SIP is mainly used for session management, whereas XMPP uses structured data exchange, and the data is passed using streaming pipes. 

SIP is a communication application layer protocol that is used for instant messaging and phone calls over the internet.

They are text-based protocols that don’t require a server and have many telephony features such as conferencing and Caller ID update. They are primarily [urposed to maintain, terminate as well as modify multimedia communications.

XMPP is similar to SIP but an Open source Extensible Markup Language protocol, which requires the use of a server for the data transfer. They are based on XML – based client-server architecture.

They use structured data exchange, and the data are passed via streaming pipes.

Comparison Table

Parameters of Comparison	SIP	XMPP
Definition	A communication protocol for controlling and signaling the online communication sessions.	A communication protocol is used for transferring messages as well as communication with the servers.
Protocol used	They use a text-based request-response protocol that is similar to HTTP where core attributes such as headers and message body are used.	They use XML-based client-server architecture and via a streaming connection, XMPP sends its request, response, and error messages using XML.
Purpose	They are purposed for providing session establishment and negotiation without the use of servers and handling the actual data.	Their purpose is for instant messaging and presence, and to provide structured data exchange between groups of clients using servers
Transport	They work over connection-less UDP, TCP, and also over TLS transport.	They are implemented in over-connection-oriented TCP or TLS transport.
Connection	In the case of NATs and firewalls, the extensions are used for the server to send messages to clients as it works well with TLS and TCP transport.	In case of NATs and Firewalls, the extensions are used only for restricted firewalls, but for the above, it works fine.

What is SIP?

SIP stands for Session Initiation Protocol and is the application layer communication protocol that doesn’t require server access to signal the message.

Thye is mainly purposed for the signaling, modifying, and termination of multimedia communications. They are used to make VoIP calls, video calls as well as instant messaging.

Based on a text-based request-response protocol that is similar to HTTP, SIP has the flexibility that it can be run over both TCP and UDP as well and also TLS.

Being an inherently peer-to-peer protocol, SIP has more scalability as they don’t have to go to the server in case of instant message, and thus the bandwidth and processing time with the server is saved.

But here, the limitation is, the message will not be stored on the server like XMPP. Also, SIP can doesn’t work well with NATs and firewalls, and thus other extensions are used.

What is XMPP?

XMPP stands for Extensible Presence Protocol, which is an XML-based client-server protocol, which is used for real-time messaging.

Created in 1999 by Jabber open-source community, XMPP is similar to SIP with the difference that they make use of the server for the request and response and involves structured data exchange.

They use streaming pipes, and via that, the responses, requests, and also errors or indications are passed. They use connection-based protocols such as TCP and TLS.

Since they are client-server architecture, they work well with the NATs and Firewalls. They also support many features like:

• Last activity
• Message delivery notification.
• Can create their XMPP server
• conference chat sessions

However, they have missed some telephony features such as fax sessions, transfer, etc. They are suitable when implementing a full IM platform.

Main Differences Between SIP and XMPP

1. SIP is a communication protocol and is a text-based request-response protocol, whereas XMPP is an open Extensible Markup Language protocol and is based on XML-based client-server architecture.
2. SIP doesn’t require the need for a server as the communication can be initiated without that, whereas XMPP uses a server for connection establishment.
3. In SIP, the messages are signaled using SIP headers and body, whereas In XMPP, the messages are signaled using a streaming pipe, and the request, response, errors are also passed via a streaming pipe.
4. SIP has the flexibility of using connection-less UDP, TLS, and TCP, whereas XMPP only runs TCP and TLS.
5. SIP doesn’t work with NATs and Firewalls as the user agent only sends and receives the messages wheres In XMPP. It works well with NATs and firewalls as only the client insatiate the messages to the server.
6. SIP doesn’t use the actual data, whereas XMPP handles the actual data.

References

1. https://dl.acm.org/doi/abs/10.1145/2905055.2905319
2. https://www.koreascience.or.kr/article/JAKO201436351074913.page