ATMSIGD(8)

NAME
atmsigd - ATM signaling demon

SYNOPSIS
atmsigd [-b] [-c config_file] [-d] [-D dump_dir] [-l logfile] [-n] [-N] [-q qos] [-t trace_length] [[itf.]vpi.vci [input output]]

DESCRIPTION
atmsigd implements the ATM UNI signaling protocol. Requests to establish, accept, or close ATM SVCs are sent from the kernel (using a comparably simple protocol) to the signaling demon, which then performs the dialog with the network.

Note that atmsigd is not able to accept or establish connections until the local ATM address of the interface is configured by ilmid or manually using atmaddr.

The default signaling VC (interface 0, VPI 0, VCI 5) can be overridden on the command line by specifying a different PVC address.

When overriding the default VC, optionally a pair of named pipes to use for communicating with the user of signaling can be specified. Normally, the kernel is the user of signaling and atmsigd opens a special socket for communication with it.

If atmsigd is killed, all system calls requiring interaction with it will return with an error and set errno to EUNATCH.

OPTIONS

-b  Run in background (i.e. in a forked child process) after initializing.

-c config_file
    Use the specified configuration file instead of /etc/atmsigd.conf If an option is specified in the configuration file and on the command line, the command line has priority.

-d  Enables (lots of) debugging output. By default, atmsigd is comparably quiet.

-D dump_dir
    Specifies the directory to which atmsigd will write status and trace dumps. If tracing is not yet enabled, the trace size is automatically set to a (small) default value.

-l logfile
    Write diagnostic messages to the specified file. The special name syslog is used to send diagnostics to the system logger, stderr is used to send diagnostics to standard error. If -l is absent, the setting in atmsigd.conf is used. If atmsigd doesn't specify a destination either, messages are written to standard error.

-n  Prints addresses in numeric format only, i.e. no address to name translation is attempted.

-N  Makes atmsigd behave like the network side of the UNI (useful if you have two PCs but no switch). Normally, it acts as the user side.

-q qos
    Configures the signaling VC to use the specified quality of service (see qos(7) for the syntax). By default, UBR at link speed is used on the signaling VC.

-t trace_length
    Enables tracing and sets the number of entries that should be kept in the trace buffer.

FILES
/etc/atmsigd.conf
    default configuration file
/var/tmp/atmsigd.pid.status.version
    default location of status dumps
/var/tmp/atmsigd.pid.trace.version
    default location of signaling trace dumps

DEBUGGING
When receiving a SIGUSR1 signals, atmsigd dumps the list of all internal socket descriptors. With SIGUSR2, it dumps the contents of the trace buffer. If a dump directory was set, dumps are written to files called atmsigd.pid.status.number and atmsigd.pid.trace.number, respectively, with number starting at zero and being incremented for every dump. If no dump directory is set, dumps are written to standard error.

Dumps are also generated whenever atmsigd detects a fatal error and terminates. No attempt is made to catch signals like SIGSEGV.

BUGS
The generation of traces is a comparably slow process which may already take several seconds for only 100 trace entries. To generate a trace dump, atmsigd therefore forks a child process that runs in parallel to the signaling demon.

AUTHOR
Werner Almesberger, EPFL LRC <werner.almesberger@lrc.di.epfl.ch>

SEE ALSO
atmaddr(8), atmsigd.conf(4), ilmid(8), qos(7)