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.
Run in background (i.e. in a forked child process) after initializing.
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.
Enables (lots of) debugging output. By default, atmsigd is comparably
Specifies the directory to which atmsigd will write status and trace
dumps. If -D is not specified, dumps are written to /var/tmp.
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.
Set the mode of operation. The following modes are available: user for
the user side (the default), network for the network side (useful if you
have two PCs but no switch), and switch for operation with a signaling
relay in a switch.
Prints addresses in numeric format only, i.e. no address to name translation
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.
Sets the number of entries that should be kept in the trace buffer.
-t 0 disables tracing. If -t is not specified, atmsigd
uses a default of 20 trace entries.
Sets the signaling mode. The following modes are supported: uni30 for
UNI 3.0, uni31 for UNI 3.1, uni31+uni30 for UNI 3.1 with 3.0
compatibility, uni40 for UNI 4.0, and uni40+q.2963.1 for UNI 4.0
with Q.2963.1 peak cell rate renegotiation.
Prints the version number of atmsigd on standard output and exits.
default configuration file
default location of status dumps
default location of signaling trace dumps
When receiving a SIGUSR1 signal, 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
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.
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.