M-Link vs Openfire: What’s the Difference?

Choosing the right XMPP (Extensible Message and Presence Protocol) server is a critical decision for organisations that rely on secure, reliable communications, especially in challenging environments. XMPP is an open standard protocol for real-time communication.

Openfire and M-Link are both XMPP servers, but they’re built with very different goals in mind. Openfire is a popular open-source option, while M-Link offers specialised capabilities engineered for critical military and government environments. They both support the standard messaging functions that organisations need, such as 1:1 chat, multi-user chat (MUC), and file sharing.

M-link:

M-link is our suite of XMPP server products built to deliver secure, high-performance server software for a range of requirements. It excels in demanding environments where robust security, seamless interoperability, and high performance over constrained networks are critical.

• M-Link User Server: The main XMPP server, supporting 1:1 chat, presence, and Multi-User Chat (MUC).
• M-Link IRC Gateway: Bridges IRC and XMPP networks by linking IRC channels to XMPP MUC rooms, allowing users on both platforms to communicate seamlessly.
• M-Link MU Server: Typically deployed on a mobile unit (such as an aircraft or naval vessel), the M-Link MU Server supports XMPP Chat over constrained networks via XEP-0361 and XEP-0365.
• M-Link MU Gateway: M-Link MU Gateway serves as the gateway system for XMPP servers on high-quality links and those running over constrained networks, enabling them to communicate and exchange messages.
• M-Link Edge: Provides an XMPP Boundary Guard service to protect organisational boundaries and provide cross-domain services.

Openfire:

Openfire is an open source XMPP server originally developed by Jive Software and now managed by the Ignite Realtime Foundation. It is designed for general-purpose use and provides a series of plugins to enhance its core capabilities and make it suitable for specialised deployments.

NATO Openfire Plugins

While M-Link is designed to provide native support for military requirements, Openfire is built to make use of third-party plugins. To ensure that Openfire is suitable for military deployments, NATO provides several specialised plugins to its members. The most prominent of these are listed below:

• Forms Discovery and Publishing (FDP): This is important for military operations; users can easily create forms of one or more types, which will then be shared with other users in the MUC room and third parties. It’s used in time-sensitive operations such as MEDVAC evacuations.
• Security Label Lookup: Using the Openfire Plugin for XMPP Security Labels, users are able to set security labels on 1:1 messages and within MUC. This plugin provides users with a preauthorised list of labels that can be applied, however it does not provide security-based access control.

Common Functionality

Both M-Link and Openfire are fully standard-compliant XMPP servers. Any organisation evaluating either product can expect the following capabilities:

• Real-time Messaging: 1:1 chat and multi-user chats with low latency using the open XMPP protocol.
• Presence Management: Users can see the availability and status of other users within an organisation in real-time, supporting decisions being made, which is important in mission-critical situations.
• Federation: Server-to-server communication that enables users across different XMPP deployments to exchange messages, supporting interoperability between departments or partner organisations.
• Multi-User Chat (MUC): Group chat rooms for team coordination, operational briefings, and collaborative working.

These shared capabilities mean that both XMPP servers meet the baseline communications requirements of most organisations.

M-Link Differentiation

For defence and government military operations, the differentiating question is rarely whether a server can deliver messaging; it’s whether it can deliver messaging under the conditions and constraints of challenging operations. M-Link is engineered specifically for these conditions.

• Security Label-Based Access Control: Messages carry security labels, applying clearance-based access controls on individual messages and multi-user chat rooms. This ensures that users only receive messages they are cleared to see in both 1:1 and group communications. This access control is also used to form part of M-Link’s compliance with STANAG 4774/8.
• Constrained Network Operations: M-Link Mobile Unit supports XEP-0361, which is a Zero Handshake Server-to-Server Protocol to reduce connection overhead on slow links, and XEP-0365 for XMPP communication over STANAG 5066, the standard protocol for HF radio.
• Server Clustering: Allows multiple XMPP domains to be collectively hosted by the servers in the cluster. Clustering synchronises state between servers to ensure messages are routed to the correct destinations, maintain accurate presence information, and ensure that services like Multi-User Chat (MUC) and Publish-Subscribe (PubSub) continue operating even if a node fails. It is optimised for LAN environments and is designed to work effectively in WAN environments with LAN-like properties. While Openfire does support clustering, it is not native and requires a third-party plugin to be installed on the system.
• Federated Multi-User Chat (FMUC) – Standard Multi-User Chat (MUC) relies on a stable link between the server that hosts the MUC room and the users. This is fine for most scenarios; however, when operating over a constrained link, this can cause issues as users are likely to drop connection or have their link disrupted. M-Link utilises FMUC to ensure that, instead of being disconnected from their MUC room when a link is disrupted or fails, users can still use their MUC rooms as normal, as they operate on a local version of the server, with messages being sent once the link is re-established. This is done through XEP-0289: Federated MUC for Constrained Environments.Openfire currently provides an experimental version of FMUC.
• Cross-Domain Boundary Control: M-Link Edge controls what crosses organisational boundaries, including features like message filtering, presence folding, and peer authentication. Combined with M-Guard, it enables fully controlled messaging across different security domains
• Peering Controls: Administrators can define policies for server-to-server communication. Giving them control over who can access certain domains or MUC rooms, what level of authentication is required, and what message types are permitted. Controls include presence folding, message folding, and the ability to prevent specific traffic types, such as in-band file transfer.
• All-in-one Software: The M-Link platform provides everything as standard, without the need to install, verify, and manage multiple plugins to add necessary functionality to the XMPP server.

Both M-Link and Openfire deliver core XMPP messaging capabilities, but the difference becomes clear in defence operational environments where secure communication is the main goal. M-Link provides the capabilities needed in defence operations.

From operating over constrained networks to enforcing security labelling and controlled cross-domain communication, M-Link is engineered to deliver specialised capabilities where standard solutions fail.

Find out more about the M-Link product suite on the website.