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

# dtpcd(1)

DTPC daemon task for receiving and processing DTPC ADUs in bundles

## NAME

dtpcd - DTPC daemon task for receiving and processing DTPC ADUs in bundles

## SYNOPSIS

**dtpcd**

## DESCRIPTION

**dtpcd** is a background "daemon" task that manages the reception and processing of DTPC protocol data units.  It receives the payloads of bundles destined for the "ipn"-scheme endpoint whose node number is the number of the local node and whose service number is the DTPC\_RECV\_SVC\_NBR (129 as of the time of this writeng).

DTPC protocol data units are of two types: application data units (ADUs, i.e., aggregations of application data items) and acknowledgments.  Each acknowledgment is interpreted as authorization to release the buffer space occupied by the node's local copy of the acknowledged ADU.  Each ADU is parsed into its constituent application data items, which are then delivered to the applications awaiting them, and when required a DTPC end-to-end acknowledgment PDU is returned to the DTPC PDU sender.

## EXIT STATUS

- 0

  **dtpcd** 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 **dtpcadmin** to restart **dtpcd**.

- 1

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

## FILES

No configuration files are needed.

## ENVIRONMENT

No environment variables apply.

## DIAGNOSTICS

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

- DTPC can't open own 'send' endpoint.

  Bundle protocol agent has not been started.  See [*ion*(3)](/ion/3.md).

- dtpcd can't attach to DTPC.

  **dtpcadmin** has not yet initialized DTPC protocol operations.

## BUGS

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

## SEE ALSO

[*dtpcadmin*(1)](/dtpcadmin/1.md), [*ion*(3)](/ion/3.md)