You can use ACE or Boost.Asio:
About ACE:
Increased portability -- ACE components make it easy to write concurrent networked applications on one OS platform and quickly port them to many other OS platforms. Moreover, because ACE is open source, free software, you never have to worry about getting locked into a particular operating system platform or compiler configuration.
About boost:
Boost.Asio is a cross-platform C++ library for network and low-level I/O programming that provides developers with a consistent asynchronous model using a modern C++ approach.
