What is iad1 1030/tcp BBN IAD

["VanMeter, John" <John.VanMeter () ost dot gov>]

I did a scan of a NT 4.0 SP6a server and found the following

iad1 1030/tcp BBN IAD

I found the following during a search on the web "I think you mean you found
these in the /etc/services file, right? I seriously doubt you're seeing
traffic on these ports. The presence of these in this file is to document
the services, and to support 'getservbyname()' -- it doesn't mean your
system is supporting these services. the BBN (Bolt, Beranek and Newman)
Interface Access Device, which operates as a bridge/router between IP, X.25,
asynch links, etc."

Can someone help me understand what is going on?

Thank you
John van Meter