NAME¶

dgrcla - DGR-based BP convergence layer adapter (input and output) task

SYNOPSIS¶

dgrcla local_hostname[:local_port_nbr]

DESCRIPTION¶

dgrcla is a background "daemon" task that spawns two threads, one that handles DGR convergence layer protocol input and a second that handles DGR convergence layer protocol output.

The input thread receives DGR messages via a UDP socket bound to local_hostname and local_port_nbr, extracts bundles from those messages, and passes them to the bundle protocol agent on the local ION node. (local_port_nbr defaults to 1113 if not specified.)

The output thread extracts bundles from the queues of bundles ready for transmission via DGR to remote bundle protocol agents, encapsulates them in DGR messages, and sends those messages to the appropriate remote UDP sockets as indicated by the host names and UDP port numbers (destination induct names) associated with the bundles by the routing daemons that enqueued them.

Note that dgrcla is a "promiscuous" convergence layer daemon, able to transmit bundles to any DGR destination induct. Its duct name is the name of the corresponding induct, rather than the induct name of any single DGR destination induct to which it might be dedicated, so scheme configuration directives that cite this outduct must provide destination induct IDs. For the DGR convergence-layer protocol, destination induct IDs are identical to induct names, i.e., they are of the form local_hostname[:local_port_nbr].

dgrcla 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. dgrcla can also be spawned and terminated in response to START and STOP commands that pertain specifically to the DGR convergence layer protocol.

EXIT STATUS¶

"0"

dgrcla 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 dgrcla.

"1"

dgrcla 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 dgrcla.

FILES¶

No configuration files are needed.

ENVIRONMENT¶

No environment variables apply.

DIAGNOSTICS¶

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

dgrcla can't attach to BP.

bpadmin has not yet initialized Bundle Protocol operations.

No such dgr induct.

No DGR induct with duct name matching local_hostname and local_port_nbr has been added to the BP database. Use bpadmin to stop the DGR convergence-layer protocol, add the induct, and then restart the DGR protocol.

CLI task is already started for this engine.

Redundant initiation of dgrcla.

No such dgr induct.

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

Can't get IP address for host

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

dgrcla can't open DGR service access point.

DGR system error. Check prior messages in ion.log log file, correct problem, and then stop and restart the DGR protocol.

dgrcla can't create sender thread

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

dgrcla can't create receiver thread

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

BUGS¶

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

SEE ALSO¶

bpadmin(1), bprc(5)