This document describes the TCP/IP protocol used by Bacula to communicate between the various daemons and services. The definitive definition of the protocol can be found in src/lib/bsock.h, src/lib/bnet.c and src/lib/bnet_server.c.

Bacula's network protocol is basically a ``packet oriented'' protocol built on a standard TCP/IP streams. At the lowest level all packet transfers are done with read() and write() requests on system sockets. Pipes are not used as they are considered unreliable for large serial data transfers between various hosts.

Using the routines described below (bnet_open, bnet_write, bnet_recv, and bnet_close) guarantees that the number of bytes you write into the socket will be received as a single record on the other end regardless of how many low level write() and read() calls are needed. All data transferred are considered to be binary data.

Kern Sibbald 2010-08-30