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NAME

dccplso - DCCP-based LTP link service output task

SYNOPSIS

dccplso {remote_engine_hostname | @}[:remote_port_nbr] remote_engine_nbr

DESCRIPTION

dccplso is a background "daemon" task that extracts LTP segments from the queue of segments bound for the indicated remote LTP engine, encapsulates them in DCCP datagrams, and sends those datagrams to the indicated DCCP port on the indicated host. If not specified, port number defaults to 1113.

Each "span" of LTP data interchange between the local LTP engine and a neighboring LTP engine requires its own link service output task, such as dccplso. All link service output tasks are spawned automatically by ltpadmin in response to the 's' command that starts operation of the LTP protocol, and they are all terminated by ltpadmin in response to an 'x' (STOP) command.

EXIT STATUS

  • "0"

    dccplso 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 ltpadmin to restart dccplso.

  • "1"

    dccplso terminated abnormally, for reasons noted in the ion.log file. Investigate and solve the problem identified in the log file, then use ltpadmin to restart dccplso.

FILES

No configuration files are needed.

ENVIRONMENT

No environment variables apply.

DIAGNOSTICS

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

  • dccplso can't initialize LTP.

    ltpadmin has not yet initialized LTP protocol operations.

  • No such engine in database.

    remote_engine_nbr is invalid, or the applicable span has not yet been added to the LTP database by ltpadmin.

  • LSO task is already started for this engine.

    Redundant initiation of dccplso.

  • LSO can't create idle thread.

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

  • LSO can't open DCCP socket. This probably means DCCP is not supported on your system.

    Operating system error. This probably means that you are not using an operating system that supports DCCP. Make sure that you are using a current Linux kernel and that the DCCP modules are being compiled. Check errtext, correct problem, and restart dccplso.

  • LSO can't connect DCCP socket.

    Remote host's dccplsi isn't listening or has terminated. Restart dccplsi on the remote host and then restart dccplso.

  • Segment is too big for DCCP LSO.

    Configuration error: segments that are too large for DCCP transmission (i.e., larger than 65535 bytes) are being enqueued for dccplso. Use ltpadmin to change maximum segment size for this span.

BUGS

Report bugs to <https://github.com/nasa-jpl/ION-DTN/issues>

SEE ALSO

ltpadmin(1), ltpmeter(1), dccplsi(1), owltsim(1)