What applications use tcp port 411 (Remote MT protocol)

[bdubrow]

I am seeing a high amount of traffic that is using tcp port 411. I know the well known port indicates Remote MT protocol but what applications use the port? TIA

 

[AlfSutherland]

Hi, Port 411 is used in the Directory assistance service. The Directory service is provided to applications through the Directory Access Protocol (DAP), which binds a Directory User Agent(DUA) to a Directory System Agent (DSA).

Please refer to RFC 1202;

http://www.cis.ohio-state.edu/cgi-bin/rfc/rfc1202.html

rmt 411/tcp Remote MT Protocol
rmt 411/udp Remote MT Protocol
# Peter Eriksson <pen@lysator.liu.se>
I hope this helps, Alf Sutherland