Service: insitu-conf (VocalTec Internet Phone Conference Engine)
Port: 1490
Protocol: TCP
Range: Registered ports (1024-49151)
What Runs on Port 1490
Port 1490 was registered for the insitu-conf service, part of VocalTec's Internet Phone software. While the primary voice communication happened on other ports, port 1490 specifically handled the conference collaboration features: whiteboard sharing, text chat, and file transfers during voice calls.1
The service operated over TCP, ensuring reliable delivery of shared files and synchronized whiteboard data between conference participants.
The Story: The First Internet Phone Call
In February 1995, a small Israeli company called VocalTec released something revolutionary: Internet Phone, the world's first VoIP software.2 Before this, the Internet was for documents, email, and text. VocalTec made it possible to speak.
The company was founded by Alon Cohen and Lior Haramaty, who had met while serving together in the IDF and incorporated their company in 1989. Their key invention was the "Audio Transceiver"—a dynamic jitter buffer that handled the messy reality of packet networks: delays, packet loss, packets arriving out of order. This made real-time voice possible over the unreliable Internet.2
But voice alone wasn't enough. If you were going to have a conference over the Internet, you needed the things that made conferences useful: the ability to sketch ideas together, chat when someone's audio cut out, share files. The insitu-conf service on port 1490 provided these features.
What This Port Represented
Port 1490 represents the moment when the Internet stopped being a document network and became a communication medium. VocalTec's software made the first computer-to-computer voice calls in 1995, expanded to computer-to-telephone in 1998, and eventually telephone-to-telephone.2
The company went public on NASDAQ in February 1996, partnered with Microsoft NetMeeting in 1996, and their technology powered early Internet calling services like Deltathree in 1997.2
Before Zoom, before Skype, before Discord or Teams or any of the video conferencing tools we take for granted, there was port 1490—quietly enabling people to share whiteboards and files while talking over the Internet for the first time.
What Happened to This Service
VocalTec's Internet Phone is long obsolete. The protocols evolved, the standards changed, and modern conferencing platforms use entirely different approaches. Port 1490, once carrying the future of communication, now sits mostly unused.
But its registration remains in the IANA database—a historical marker of where Internet conferencing began.
Registered Ports and the IANA Registry
Port 1490 belongs to the registered ports range (1024-49151). These ports are assigned by IANA to specific services upon request. Unlike well-known ports (0-1023) which require root privileges, registered ports can be used by ordinary applications.
When VocalTec requested port 1490 for their conference engine, they were building something genuinely new. There was no established way to do what they were attempting. The port assignment gave them a stable, recognized number that other software could connect to.
Many registered ports from the 1990s tell similar stories—experimental services, proprietary protocols, attempts to solve problems that didn't have standard solutions yet. Some became foundations of the modern Internet. Others, like port 1490, became historical artifacts.
Security Considerations
Port 1490 is rarely used today, which means if you see traffic on this port, it's worth investigating. Historical trojans and malware have occasionally used defunct registered ports precisely because they're unexpected.3
To check what's listening on port 1490 on your system:
Linux/macOS:
Windows:
If nothing is running on this port (the common case), these commands will return no results.
Related Ports
VocalTec's Internet Phone used multiple ports for its various functions. Port 1490 specifically handled conference collaboration features, while other ports managed the actual voice data and signaling.
Other early VoIP and conferencing systems used their own port assignments:
- Port 1720: H.323 call signaling (a later VoIP standard)
- Port 5060: SIP (Session Initiation Protocol, which largely replaced proprietary VoIP protocols)
Why This Port Matters
Most ports are forgettable. They carry routine traffic, implement boring protocols, exist because some standard required a number. Port 1490 is different.
This port represents a moment of genuine innovation—when a small team in Israel figured out how to transmit voice reliably over a packet network that was never designed for real-time communication. The fact that we now take video calls for granted, that we share screens and whiteboards without thinking about it, that "jump on a Zoom" is casual office language—all of that started with experiments like the service that ran on port 1490.
The technology is obsolete. The port is unused. But the idea—that the Internet could carry human voices, enable collaboration, make distance irrelevant—that idea changed everything.
Frequently Asked Questions About Port 1490
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