This chapter describes network interfaces, devices and protocols in the C5 product. The goal is to improve your understanding of what is available in the C5 operating system before you begin setting up networking on a C5 system. This chapter does not describe how to set up network components.
Network protocols define how messages are formatted and packaged for transmission over the network. They provide support for sockets, which are endpoints for communication, described in socket (2POSIX).
C5 systems provide support for the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP) over the Internet Protocol (IP). TCP is a high-level, reliable, connection-oriented protocol. It verifies that messages it sends get to their destinations and re-sends them if necessary. To do so, TCP relies on connections between the sender and the receiver. In contrast, UDP is also high-level, but is unreliable. It sends messages without verifying if they arrive, making UDP faster and lighter on system rescources than TCP. Both TCP and UDP sit atop the lower-level IP, the transport protocol for the Internet. This version of the C5 operating system supports IPv6 and IPv4. Both UDP and TCP are supported over both versions of IP. For details about the C5 implementations of these protocols, see ip(7P), ip6(7P), tcp(7P). udp(7P). See also inet6(7P) and icmp6(7P). This guide provides information on IPv6. See Section 12.2, “IPv6 and the C5 System”.
C5 systems also support remote inter-process communication (remote IPC), by allowing you to create an IPC stack in the C_OS system actor and attach the stack to an Ethernet device. For details, see ethIpcStackAttach(2K) and IPC(5FEA). A chapter on Configuring IPC is provided with this guide. See Chapter 14, Configuring IPC.
Finally, C5 systems provide a mechanism to support Open Systems Interconnect (OSI), by allowing you to attach an OSI stack that you provide to an Ethernet device. For details, see ethOsiStackAttach(2K).