Port identification
  - issues ensuring both parties know the right addr/port
  - entered by user/admin (communicated by other means)
  - hard coded in .h files 
  - loaded from config file 
  - default (from one of above) overridden by port/addr
         included in a message
  - issues with port contention with other clients/servers and apps
  - single port vs selecting from a port range 

Comm methods
  - set up recv socket, send socket
  - set up send (host, port, sets flag and descriptor and send addr/port)
  - set up recv (port, sets flag and descriptor and recv addr/port)
  - send (check if socket set up and matches target)
  - recv (check if socket set up)
  - close recv (close socket and clear flag)
  - close send (close socket and clear flag)
  - things like ack sequence/format left to the client/server apps

Comm fields
  - flags for whether send/recv sockets currently set up
  - descriptors and structs for send/recv sockets and addr
  - current send addr and port
  - current recv addr and port

Synchronizing client local machine time with server local machine time
  - can use server's time and modify for time zone
    BUT what if client or server's time is off by a bit (or a lot)?
  - calc shortest round trip comm time, split the difference, and use that as
    the offset between client and server times?