About Protocol Replies
The protocol reply classes encapsulate protocol replies typical of common Internet protocols. Protocol replies are returned from calls to client protocol command methods. Protocol-specific portions of the reply hierarchy are explained in the sections on the individual protocols. Figure 5 shows the general reply hierarchy.
Figure 5 – Hierarchy of the protocol reply classes 
RWReply is the abstract base class from which all protocol replies inherit. It is part of the Internet Basics package.
RWNumReply, which inherits directly from RWReply, encapsulates a numerical protocol reply. A numerical protocol reply is made up of single-line numerical replies contained in RWNumReplyLine objects. RWNumReply and RWNumReplyLine are part of the Internet Basics package.
RWFtpReply, RWHttpReply, and RWSmtpReply are specific protocol replies for FTP, HTTP, and SMTP. They inherit from RWNumReply. The RWPop3Reply class inherits directly from RWReply, because the POP3 protocol does not use numerical responses.
