Port 1348: BBN-MMX — A fossil from the birth of video conferencing

Port 1348 was registered by BBN (Bolt, Beranek and Newman) for multimedia conferencing. It's a historical artifact from when streaming video over the Internet was experimental research, not a button you click without thinking.

What Runs on This Port

Service name: bbn-mmx
Official purpose: Multi-media conferencing
Protocols: TCP and UDP
Status: Registered with IANA, but likely unused today

BBN registered this port for their multimedia conferencing systems in the 1990s¹. These were experimental systems exploring how to send real-time audio and video across packet networks—networks that were designed for email and file transfer, not live streams.

The experiments worked. The specific protocols didn't survive, but the concepts did. Every video call you make today descends from this research.

Who Was BBN?

If you've used the Internet, you've used BBN's work.

BBN built the first packet-switching routers (they called them Interface Message Processors) for ARPANET in 1969². They developed email as we know it (@-style addresses). They pioneered voice over packet networks. They figured out how to make real-time multimedia work over connections that were never designed for it.

Port 1348 was part of that exploration. BBN's multimedia conferencing systems used experimental protocols like ST (STream protocol) for resource reservation and real-time data delivery³. They built systems that could coordinate shared documents, presentation tools, and video across multiple participants—concepts that seemed futuristic in the early 1990s and mundane today.

Why This Port Matters

It doesn't, practically. You won't find active services on port 1348. The specific protocols BBN developed have been replaced by H.323, SIP, WebRTC, and other standards that solved the same problems more broadly.

But historically, it matters. This port represents a moment when nobody knew if video conferencing over the Internet would even work. BBN figured it out. The port number remains in the registry like a timestamp—a marker of when video calls transformed from science fiction to engineering problem to solved problem.

The Registered Ports Range

Port 1348 lives in 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 to bind to, registered ports can be used by regular user processes.

Many registered ports have fallen into disuse as the protocols they served became obsolete. Port 1348 is likely one of them. The registration remains, but the multimedia conferencing systems it was designed for have been replaced by modern alternatives.

Security Considerations

Some older sources mention port 1348 in the context of potential trojan or malware use⁴. This is common for lesser-known ports—malware authors sometimes use obscure registered ports for command-and-control traffic, betting that unusual activity won't be noticed.

If you see unexpected traffic on port 1348, investigate:

# See what's listening on port 1348
sudo lsof -i :1348
# or
sudo netstat -tulpn | grep 1348

Legitimate BBN multimedia conferencing software is unlikely to be running on modern systems. Any activity on this port warrants scrutiny.

From Experiment to Infrastructure

BBN's multimedia conferencing work explored fundamental questions: How do you guarantee bandwidth for real-time streams on a best-effort network? How do you synchronize audio and video that arrive via different routes? How do you coordinate multiple participants without a central controller?

The answers became RTP (Real-time Transport Protocol), RTCP (Real-time Control Protocol), SDP (Session Description Protocol), and the entire infrastructure that makes video calls work. Port 1348 was a workshop where these problems were being solved.

The port itself is unused. The work it represents runs the Internet.