Sérgio Freire
PT Inovação/IEETA/UA
This paper presents a simple name service for TCP ports, allowing services to be reached by name instead of number. Names are arbitrary byte arrays that are bound to listening ports. Name resolutions take place during the TCP three-way handshake, not requiring extra message exchanges. The new TCP handshake conforms with the standard and is fully compatible with existing TCP implementations. A prototype implementation was developed in Linux, paying special attention to backward compatibility with legacy systems (kernels and applications). Among the many opportunities created by the name service, it allows services with unusual names, known only by small communities, to remain undetected by port scanners (though not by network sniffers).