Web services are usually exposed by the web server, or by an app server (in the case of Java web services) that expose the service on an HTTP or HTTPS port. No need to open a socket since web requests are passed to the web service via the web/app server. On Windows 2000, XP, 2003 servers, this means IIS and ASP.NET handle the web service requests, unless you're using an alternative web server/app server to handle web services. See:
Microsoft Web Services Developer Center
XML Web Services Created with ATL Server
gSoap: C/C++ Web services
Java Technology and Web Services
Ian Mariano - http://www.ian-space.com/
"We are all wave equations in the information matrix of the universe" - me