NAME¶
dccpclo - DCCP-based BP convergence layer output task
SYNOPSIS¶
dccpclo remote_hostname[:
remote_port_nbr]
DESCRIPTION¶
dccpclo is a background "daemon" task that connects to a remote
node's DCCP socket at
remote_hostname and
remote_port_nbr. It
then begins extracting bundles from the queues of bundles ready for
transmission via DCCP to this remote bundle protocol agent and transmitting
those bundles as DCCP datagrams to the remote host.
If not specified,
remote_port_nbr defaults to 4556.
Note that
dccpclo 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
dccpclo is started.
Note also that
dccpclo has no fragmentation support at all. Therefore,
the largest bundle that can be sent via this convergence layer is limited to
just under the link's MTU (typically 1500 bytes).
dccpclo 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.
dccpclo can also be spawned and terminated in response to START and
STOP commands that pertain specifically to the DCCP convergence layer
protocol.
EXIT STATUS¶
- 0
- dccpclo 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 dccpclo.
- 1
- dccpclo 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 dccpclo.
FILES¶
No configuration files are needed.
ENVIRONMENT¶
No environment variables apply.
DIAGNOSTICS¶
The following diagnostics may be issued to the
ion.log log file:
- dccpclo can't attach to BP.
- bpadmin has not yet initialized Bundle Protocol
operations.
- No memory for DCCP buffer in dccpclo.
- ION system error. Check errtext, correct problem, and
restart dccpclo.
- No such dccp duct.
- No DCCP outduct matching local_hostname and
local_port_nbr has been added to the BP database. Use
bpadmin to stop the DCCP convergence-layer protocol, add the
outduct, and then restart dccpclo.
- CLO task is already started for this duct.
- Redundant initiation of dccpclo.
- dccpclo can't get IP address for host.
- Operating system error. Check errtext, correct problem, and
restart dccpclo.
- dccpclo can't create thread.
- Operating system error. Check errtext, correct problem, and
restart dccpclo.
- CLO 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 dccpclo.
- CLO can't initialize socket.
- Operating system error. Check errtext, correct problem, and
restart dccpclo.
- CLO send() error on socket.
- Operating system error. Check errtext, correct problem, and
restart dccpclo.
- Bundle is too big for DCCP CLO.
- Configuration error: bundles that are too large for DCCP
transmission (i.e., larger than the MTU of the link or 65535
bytes--whichever is smaller) are being enqueued for dccpclo. Change
routing or use smaller bundles.
BUGS¶
Report bugs to <ion-bugs@korgano.eecs.ohiou.edu>
SEE ALSO¶
bpadmin(1),
bprc(5),
dccpcli(1)