Port 268 is where Tobit David keeps its distributed installations synchronized. When a mobile user's notebook needs to replicate email, fax, calendars, and contacts from the central David server, that conversation happens here.
What Runs on Port 268
Port 268 (both TCP and UDP) is officially assigned to td-replica, the replication service for Tobit David.1 David is a unified messaging and groupware system that's been a cornerstone of German business communications since 1997.2
The replica service handles synchronization between the main David server and remote installations—particularly InfoCenter Mobile instances that run on notebooks and other devices for users who need offline access to their communications data.3
The Protocol
The td-replica protocol synchronizes several types of data:
- Email messages
- Fax documents
- Voice messages
- Contacts and address books
- Calendar entries and appointments
- Tasks and collaboration data
When a remote David installation connects to port 268, it requests updates since its last sync. The replica service on the main server sends changed data, and the remote installation can push local changes back. This bidirectional sync keeps distributed David installations consistent.4
The Tobit David Story
Tobit Software was founded in 1986 in Ahaus, Germany. In the early 1990s, they developed FaxWare, one of Germany's first standard solutions for electronic fax transmission.5
David launched in 1997 and became what one German IT publication called "a kind of synonym for Unified Messaging in small and large networks."5 While the rest of the world standardized on Microsoft Exchange, hundreds of thousands of German businesses built their communications infrastructure on David.
The innovation wasn't just technical. David unified channels that most systems kept separate: email, fax, voice messages, SMS, and later team collaboration tools. For German small and medium-sized businesses, David was "the most successful and popular German standard software" for unified communications.5
Port 268's replica service made distributed David deployments practical. Sales representatives could carry a synchronized copy of the David server on their notebook, work offline during travel, then reconnect and replicate changes when back online. This was genuinely useful in the late 1990s and early 2000s when constant Internet connectivity wasn't assumed.
Security Considerations
Port 268 carries sensitive business data during replication:
- Complete email archives
- Fax documents that may contain confidential information
- Contact databases
- Calendar entries revealing schedules and meeting details
The protocol should only be exposed on trusted networks. If you need to replicate across the Internet, tunnel the traffic through a VPN. Exposing port 268 directly to the Internet gives attackers access to attempt authentication against your David server and potentially intercept replication traffic.
Check what's listening on port 268:
If you see port 268 open and you're not running Tobit David, investigate immediately. Unauthorized services binding to assigned ports are always suspicious.
Why This Port Matters
Port 268 represents a particular moment in software history: the rise of unified messaging as a category, and the surprising persistence of regional software ecosystems in an increasingly globalized market.
David's success in Germany while remaining virtually unknown elsewhere demonstrates that "industry standard" isn't universal. German businesses had different requirements, different telephony infrastructure, and different expectations about fax integration. Tobit built for that market and won it.
The replica service on port 268 solved a real infrastructure problem. It let companies deploy David in branch offices, on mobile devices, and in distributed architectures while maintaining data consistency. The sync model—replicate when connected, work offline when disconnected, reconcile changes later—feels obvious now, but it wasn't in 1997.
Port 268 still carries that traffic today. Tobit David continues to be actively developed, now branded as Team/David with modern web APIs and mobile clients.6 But the replica protocol on port 268 remains, a 27-year-old piece of infrastructure still doing its job.
Related Ports
- Port 267 — td-service, Tobit David Service Layer for core communications
- Port 25 — SMTP, the standard email transport that David integrates with
- Port 143 — IMAP, used by David clients to access mail via standard protocols
- Port 443 — HTTPS, used by modern David web APIs and clients
Frequently Asked Questions
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