Requires Optional X.25 Software

NAME

padem − Pad emulation for X.25/9000 interface with PAD support

SYNOPSIS

padem [-p profid] [-l level [-f filename]] [-v] [-g nn] [-r] [-u abc] address|symad
padem [-p profid] [-i programmatic_interface_name] [-l level [-f filename]] [-v]

DESCRIPTION

padem is used to connect the local terminal with a remote host, whose X121 address is address or whose symbolic name is symad, by means of the HP X.25/9000 interface.  If address or symad is specified, padem makes a connection with the remote host directly, along with the associated facility fields, and enters the DATA TRANSFER state.  Otherwise, padem enters the PAD COMMAND state, indicated by its prompt X28> (provided X.3 parameter 6 is set to 5). 

With minor exceptions (see CCITT X.3, X.28, X.29 RECOMMENDATIONS), padem implements all recommendations, as defined by CCITT and thus gives full PAD support for outgoing calls.  padem operates in three modes:

• Data transfer mode, entered either at program invocation time (see SYNOPSIS above) or after the virtual circuit (VC) has been established (see Commands below),

• Command mode without connection, entered at program invocation,

• Command mode with connection which happens when the Escape-From-Data-Transfer-Mode byte is entered during the data transfer mode. 

In data transfer mode, typed text is sent to the remote host, and text received from remote host is displayed (unless X.3 parameter 8 is set to 1).  To issue a padem command signal when in data transfer mode, command mode must be re-entered by using the Escape From Data Transfer Mode key.  In command mode, padem receives X.28 PAD commands from users (see X28 PAD Command Set below.) 

If the VC is cleared at any time, either by the remote host or by the X.25 network, padem returns from data transfer mode back to command mode. 

Options

padem supports the following options:

-p profid profid is a profile identifier that will be loaded when padem is started.  This profile is called the initial profile.  The profile describes the X.3 configuration for the login session.  If it is missing, the profile is taken from the /etc/x25/x29hosts file.  X.3 parameter profiles are stored in file /etc/x25/x3config. 

-i programmatic_interface_name
programmatic_interface_name is the name of the X.25 card through which communication is to be initialized.  If this option is missing, the programmatic interface name specified by name in /etc/x25/x29hosts is used.  The default programmatic interface name is the name for card /dev/x25_0 if it is not present in the command line or in /etc/x25/x29hosts. 

-g nn Specifies the closed user group.  It can be 0,1 or 2 digits. 

-r Reverse charging is requested. 

-u abc Specifies call user data.  abc is a character string no longer than 12. 

-l level Logging severity level, can be 0,1,2,3.  Default is 0. 

-f filename filename is the user specified filename for logging messages.  The logfiles reside in the user’s home directory; the full pathname is $HOME/filename. xxxxxx. If this option is missing, padem uses the default logfile name $HOME /plog. xxxxxx, where xxxxxx is the process ID running the padem session. 

-v Enable verbose output. 

If an option is specified on the command line and is also defined in /etc/x25/x29hosts for padem configuration, the value entered on the command line overrides the one entered in /etc/x25/x29hosts. 

Configuration

padem configuration can be controlled by managing two configuration files, /etc/x25/x29hosts and /etc/x25/x3config. 

/etc/x25/x29hosts defines the configuration for padem for each remote host.  A padem configuration entry is identified by the keyword pad_em followed by information on the remote host system beginning with { and ending with }.  The information between the open and close brackets specifies the X.121 address of the remote host, the X.25 programmatic interface name to be used for call set-up, the reverse charge option for call set-up, the logging level for login sessions to the host system, and the profile of X.3 parameters to be used for terminal input/output control.  A typical padem entry in /etc/x25/x29hosts resembles:

pad_em {
name                hptndxk0
remote_x121         4085551111
reverse_charge      enable
profile             0
logging             3
}

/etc/x25/x29hosts also defines the X.121 address and symbolic address mapping.  This configuration is identified by the host_table entry in the file.  Each line starts with remote DTE symbolic name followed by the the remote DTE’s X.121 address.  host_table{} is searched when users enter symbolic names, either on the command line or in the padem command mode.  An typical host_table entry resembles:

host_table {
gale                4085551111
tornado             4085551113
typhoon             4085551115
}

/etc/x25/x3config provides the initial X.3 parameters for padem sessions.  It contains the profile ID, the X.3 parameters, and their values for the PAD emulation session between the user’s terminal and the remote system.  The initial local X.3 parameters are loaded from the default profile id 0 defined in CCITT if the user does not specify a profile ID.  Here is an example of X.3 configuration with profile ID 0:

hp_profile : 0 {
    1       1
    2       1
    3     127
    4       0
    5       1
    6       5
    7      21
    8       0
    9       0
    10      0
    11     14
    12      1
    13      0
    14      0
    15      1
    16      8
    17     24
    18      0
    19      1
    20      0
    21      0
    22      0
}

If padem is started with command line option parameters, the option given on the command line takes precedence over corresponding parameters in /etc/x25/x29hosts.  If no options are specified, or if only some options are specified on the command line, padem matches the calling address to those listed in /etc/x25/x29hosts and gets those not specified on the command line from /etc/x25/x29hosts.  If the option is not specified in either location, padem assigns a default value as follows:

name programmatic interface name for /dev/x25_0

profile default profile 0 values from above

logging 0

reverse_charge disable

Commands

If no destination X.121 address or symbolic address is entered at the command line, padem enters PAD COMMAND state.  PAD command signals are available in command mode and are grouped into X28 PAD command set, defined by CCITT X.28 recommendation, and extended command set, which adds some new functionality.  If a destination X.121 address or a symbolic address is entered when padem is in command mode, padem enters data transfer mode.  The syntax for entering a symbolic address in command mode is

|symad|

and symad must be present in the host_table set in /etc/x25/x29hosts. 

X28 PAD Command Set

stat Display status information of a VC placed to a remote host.  padem responds with FREE if no VC is established or with ENGAGED if there is a virtual circuit established. 

par?  List all X.3 parameters and their values.  The response is a list of all parameters, each one displayed by its number, followed by :, followed by its current value. 

set n:v [,n:v] Set the X.3 parameter n to value v (see CCITT RECOMMENDATIONS below).  If there is a syntax error, padem responds with an ERR service signal and updates the diagnostic text.  All changes take effect when a new VC is established or immediately if padem is already engaged. 

set? n:v [,n:v] Set the X.3 parameter n to value v and display the current setting of all parameters.  This command is a combination of the set and par?  commands above. 

int Transmit an interrupt to the remote host. 

reset Reset a virtual circuit.  When a virtual circuit is reset, all data received but still not read is lost, and all X.3 parameters are set back to their default values (as they were set before the virtual call was established). 

clr Clear a virtual circuit.  This command disconnects the VC from the remote host. 

[r,g[n[n]]−]x121_address[subaddress][P/Dd...d]
Perform a virtual call to the remote host defined by its X.121 address. x121_address[subaddress] can be replaced with |symad| where symad is defined in the file /etc/x25/x29hosts.  P specifies the packet size negotiation.  D specifies the throughput class negotiation. 

prof [profile_id] Interpret a prepared set of command signals from a profile. Profiles must be placed in the file /etc/x25/x3config. 

Extended Command Set

quit Terminate padem.  If the virtual call is established, it is cleared. 

verbose Display more useful diagnostic text. 

help Display a short summary of padem command signals. 

list List all symbolic names for remote hosts accessible by the user

aprof List all profile IDs. 

lprof Display the last loaded profile ID. 

sleep s Suspend padem for s seconds (maximum 3600). 

ifname [def] ifname [string] Display or set X25 pgm_access_name to default or string.

X.3 Parameter Set

X.3 configuration parameters can specify terminal characteristics or input/output actions that the user wants padem to take on receipt of specific input from the user or X.29 packet from the remote PAD support. 

DIAGNOSTICS

Diagnostics on padem are provided by the [-l level [-f filename]] option or logging in /etc/x25/x29hosts. 

WARNINGS

padem can only be used on switched virtual-circuit connections. 

padem does not support local PAD parameters. 

padem does not accept incoming calls.  This functionality is provided by PAD support (see x29server(1M)).

DEPENDENCIES

The local system must have HP 9000 X.25 software installed and the remote host must have PAD support. 

AUTHOR

padem was developed by HP. 

FILES

/etc/x25/x29hosts
/etc/x25/x3config

SEE ALSO

x25init(1M), x25stat(1), x29server(1M), x29hosts(4), x3config(4). 

Installing and Administering X.25/9000 ,
Troubleshooting X.25/9000 .
X.25: The PSN Connection

STANDARDS CONFORMANCE

CCITT has defined four PAD related recommendations.  HP 9000 X.25 software already implements the first X.25 recommendation as well as X.28, X.29, and X.3 recommendations for incoming calls ( PAD support).  padem implements the last three recommendations for outgoing calls.  padem conforms to the 1984 CCITT standards.  The only exceptions to this rule are X.3 parameter 21 that is recognized by padem but whose value is ignored (not supported for PAD emulation). 

Hewlett-Packard Company  —  HP-UX Release 9.10: April 1995