TCP/IP communication services are provided to client applications
through the TCP/IP protocol module (tcpip.prt
). This module
provides the following four fundamental transport and network layer
protocols:
IP (RFC791)
ICMP (RFC792, 950)
TCP (RFC793)
UDP (RFC768)
The protocol module is not accessed directly by clients, but used through the Sockets Client API.
The module also provides a DNS service that can be accessed through
the Sockets Client API’s standard host name resolution interface,
RHostResolver
.
It is possible for TCP/IP services to be used over many types of network interface. To enable access to TCP/IP networks through a dial-up serial connection, Point-to-Point protocol (PPP) is provided.