NAME¶

tcpclo - DTN TCPCL-compliant convergence layer adapter output task

SYNOPSIS¶

tcpclo remote_hostname[:remote_port_nbr]

DESCRIPTION¶

tcpclo is a background "daemon" task that connects to a remote node's TCP socket at remote_hostname and remote_port_nbr. It sends a contact header, and it records the acknowledgement flag, reactive fragmentation flag and negative acknowledgements flag in the contact header it receives from its peer tcpcli task. It then begins extracting bundles from the queues of bundles ready for transmission via TCP to this remote bundle protocol agent and transmitting those bundles over the connected socket to that node. Each transmitted bundle is preceded by message type, segmentation flags, and an SDNV indicating the size of the bundle (in bytes).

If not specified, remote_port_nbr defaults to 4556.

Note that tcpclo is not a "promiscuous" convergence layer daemon: it can transmit bundles only to the node to which it is connected, so scheme configuration directives that cite this outduct need only provide the protocol name and the outduct name as specified on the command line when tcpclo is started.

tcpclo is spawned automatically by bpadmin in response to the 's' (START) command that starts operation of the Bundle Protocol, and it is terminated by bpadmin in response to an 'x' (STOP) command. tcpclo can also be spawned and terminated in response to START and STOP commands that pertain specifically to the TCP convergence layer protocol.

EXIT STATUS¶

"0"

tcpclo terminated normally, for reasons noted in the ion.log file. If this termination was not commanded, investigate and solve the problem identified in the log file and use bpadmin to restart the TCPCL protocol.

"1"

tcpclo terminated abnormally, for reasons noted in the ion.log file. Investigate and solve the problem identified in the log file, then use bpadmin to restart the TCPCL protocol.

FILES¶

No configuration files are needed.

ENVIRONMENT¶

No environment variables apply.

DIAGNOSTICS¶

The following diagnostics may be issued to the ion.log log file:

tcpclo can't attach to BP.

bpadmin has not yet initialized Bundle Protocol operations.

No such tcp duct.

No TCP outduct with duct name matching remote_hostname and remote_port_nbr has been added to the BP database. Use bpadmin to stop the TCP convergence-layer protocol, add the outduct, and then restart the TCP protocol.

CLO task is already started for this duct.

Redundant initiation of tcpclo.

Can't get IP address for host

Operating system error. Check errtext, correct problem, and restart TCP.

BUGS¶

Report bugs to <ion-bugs@korgano.eecs.ohiou.edu>

SEE ALSO¶

bpadmin(1), bprc(5), tcpcli(1)