class Net::SSH::Transport::ServerVersion

the authoritative reference for any queries regarding the version in effect.
Note that this class also encapsulates the negotiated version, and acts as
layer.
transport layer as part of the initialization process of the transport
and client. This is never used directly–it is always called by the
Negotiates the SSH protocol version and trades information about server

def initialize(socket, logger, timeout = nil)

negotiates the SSH protocol in effect, using the given socket.
Instantiates a new ServerVersion and immediately (and synchronously) 
def initialize(socket, logger, timeout = nil)
  @header = String.new
  @version = nil
  @logger = logger
  negotiate!(socket, timeout)
end

def negotiate!(socket, timeout)

exception.
reports an incompatible SSH version (e.g., SSH1), this will raise an
Negotiates the SSH protocol to use, via the given socket. If the server 
def negotiate!(socket, timeout)
  info { "negotiating protocol version" }
  debug { "local is `#{PROTO_VERSION}'" }
  socket.write "#{PROTO_VERSION}\r\n"
  socket.flush
  raise Net::SSH::ConnectionTimeout, "timeout during server version negotiating" if timeout && !IO.select([socket], nil, nil, timeout)
  loop do
    @version = String.new
    loop do
      begin
        b = socket.readpartial(1)
        raise Net::SSH::Disconnect, "connection closed by remote host" if b.nil?
      rescue EOFError
        raise Net::SSH::Disconnect, "connection closed by remote host"
      end
      @version << b
      break if b == "\n"
    end
    break if @version.match(/^SSH-/)
    @header << @version
  end
  @version.chomp!
  debug { "remote is `#{@version}'" }
  raise Net::SSH::Exception, "incompatible SSH version `#{@version}'" unless @version.match(/^SSH-(1\.99|2\.0)-/)
  raise Net::SSH::ConnectionTimeout, "timeout during client version negotiating" if timeout && !IO.select(nil, [socket], nil, timeout)
end