talkd - remote user communication server
Talkd is the server that notifies a user that someone else wants to
initiate a conversation. It acts a repository of invitations, responding
to requests by clients wishing to rendezvous to hold a conversation. In
normal operation, a client, the caller, initiates a rendezvous by sending
a CTL_MSG to the server of type LOOK_UP (see 〈protocols/talkd.h〉). This
causes the server to search its invitation tables to check if an
invitation currently exists for the caller (to speak to the callee
specified in the message). If the lookup fails, the caller then sends an
ANNOUNCE message causing the server to broadcast an announcement on the
callee’s login ports requesting contact. When the callee responds, the
local server uses the recorded invitation to respond with the appropriate
rendezvous address and the caller and callee client programs establish a
stream connection through which the conversation takes place.
[-d] Debug mode; writes copious logging and debugging information to
[-p] Packet logging mode; writes copies of malformed packets to
/var/log/talkd.packets. This is useful for debugging interoperability
[-q] Don’t log successful connects.
The talkd command appeared in 4.3BSD.