---
name: "udpclo"
section: "1"
platform: "linux"
package: "ion"
version: "3.2.1+dfsg-1.1"
release: "Debian 9 (Stretch)"
platforms: ["linux"]
url: "https://new.carta.tech/udpclo"
---

# udpclo(1)

UDP-based BP convergence layer output task

## NAME

udpclo - UDP-based BP convergence layer output task

## SYNOPSIS

**udpclo**

## DESCRIPTION

**udpclo** is a background "daemon" task that extracts bundles from the queues of bundles ready for transmission via UDP to remote bundle protocol agents, encapsulates them in UDP datagrams, and sends those datagrams 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 **udpclo** is a "promiscuous" CLO daemon, able to transmit bundles to any UDP destination induct.  Its duct name is '\*' rather than the induct name of any single UDP destination induct to which it might be dedicated, so scheme configuration directives that cite this outduct must provide destination induct IDs.  For the UDP convergence-layer protocol, destination induct IDs are identical to induct names, i.e., they are of the form *local\_hostname*\[:*local\_port\_nbr*\].

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

## EXIT STATUS

- "0"

  **udpclo** 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 **udpclo**.

- "1"

  **udpclo** 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 **udpclo**.

## FILES

No configuration files are needed.

## ENVIRONMENT

No environment variables apply.

## DIAGNOSTICS

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

- udpclo can't attach to BP.

  **bpadmin** has not yet initialized Bundle Protocol operations.

- No memory for UDP buffer in udpclo.

  ION system error.  Check errtext, correct problem, and restart UDP.

- No such udp duct.

  No UDP outduct with duct name '\*' has been added to the BP database.  Use **bpadmin** to stop the UDP convergence-layer protocol, add the outduct, and then restart the UDP protocol.

- CLO task is already started for this engine.

  Redundant initiation of **udpclo**.

- CLO can't open UDP socket

  Operating system error.  Check errtext, correct problem, and restart **udpclo**.

- CLO *write()* error on socket

  Operating system error.  Check errtext, correct problem, and restart **udpclo**.

- Bundle is too big for UDP CLA.

  Configuration error: bundles that are too large for UDP transmission (i.e., larger than 65535 bytes) are being enqueued for **udpclo**.  Change routing.

## BUGS

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

## SEE ALSO

[*bpadmin*(1)](/bpadmin/1.md), [*bprc*(5)](/bprc/5.md), [*udpcli*(1)](/udpcli/1.md)