Protocols for Communicating Between the Host and Target

Communication between the host and target is achieved using the rsh (remote shell) protocol. The remote shell protocol is used to execute commands remotely on the target from the host. In particular, this feature allows applications to be loaded dynamically. If the RSH feature is set to true, the rshd daemon enables the command interpreter to be run in an infinite loop to read input from the remote system, using the remote shell protocol. For more information on the rshd daemon, refer to the rshd(1M) man page.

It is also possible to communicate with the host using the telnet protocol.

In addition, ChorusOS systems provide support for TCP and UDP (User Datagram Protocol) over IP. TCP is a high-level, reliable, connection-oriented protocol that verifies that messages sent arrive at their destinations. Messages that do not reach their destination are automatically resent. This feature of TCP relies on connections between the sender and the receiver. UDP is also a high-level protocol protocol, however, it is not as reliable as TCP because UDP sends messages without verifying that they arrive. UDP is faster and not as resource-hungry as TCP.

Both TCP and UDP sit above the lower-level IP transport protocol.

For details about the ChorusOS implementations of these protocols, see the IP(7P), TCP(7P), and UDP(7P) man pages.

Two additional communication protocols are supported on ChorusOS systems, although they are not used for communicating between the host and target.

Support for remote inter-process communication (remote IPC) is provided, by enabling you to create an IPC stack in the C_OS system actor and attach the stack to an Ethernet device. For details, see the ethIpcStackAttach(2K), IPC(5FEA), and IPC_REMOTE(5FEA) man pages.

Support for Open Systems Interconnect (OSI) is provided since you are able to attach an OSI stack to an Ethernet device. For details, see the ethOsiStackAttach(2K) man page.