x25_networks(4)

Requires Optional LAN/X.25 Software

NAME

x25_networks − identifies the network types used by the system

DESCRIPTION

The network type file contains information describing the several X.25 public network types. A x25_networks file is supplied as part of the X.25/9000 product in directory /etc/x25. Entries in that file can be modified to suit individual system needs.

x25_networks contains up to 5 columns in the following order:

1. An alias which can be specified for the networktype parameter in the x25init configuration file.

Aliases appearing in this column are user-defined strings, and can consist of any character except the hash character (#), the space character, or newline. The alias must contain not more than 30 characters.

2. Network type. The network type must be one of the network names that appear in column two of the supplied file.

If adding an entry to this file, use the “generic” networks which are defined in the original x25_networks file (L3_DTE or L3_DCE).

If creating an entry for a variation of one of the standard public networks already recognized (such as TransPac), use that network’s network type. If a network type is not specified, the default value of DTE_84 which indicates a standard DTE that complies with the 1984 X.25 recommendation is assumed.

3. Version of the CCITT X .25 recommendation that the network honors. Only two values are allowed: either 1980 or 1984, designating which version of the CCITT X .25 recommendations the network uses.

4. Refers to network behavior and is optional. This column can contain one of 3 entries: NOFACCHK, NODUPFAC, or DDN.

NOFACCHK indicates that no facilities checking will be done on the facilities field. If NOFACCHK is not specified, the facilities are checked to ensure that they comply with the appropriate CCITT recommendations (1980 or 1984).

NODUPFAC indicates that a facility code cannot be specifed twice in the same facility/registration code field. This affects facilities such as closed user group in which only one facility may be specified; that is, incoming calls can be barred or outgoing calls can be barred, but not both.

DDN indicates that the Maximum Transmission Unit (MTU) size is to be set to 1007, and the DDN address mapping algorithm is to be used instead of the IP -to-X.121 address map table. The DDN address mapping is defined in the DDN X .25 Host Interface Specification (BBN83).

5. Also refers to network behavior and is also optional. This column can contain a second entry from the fourth column: NOFACCHK, NODUPFAC, or DDN.

EXAMPLES

Here are some example lines from the x25_networks file:

DCE_84          L3_DCE          1984    NODUPFAC
DATANET1        DATANET1        1984    NODUPFAC
DATAPAC         DATAPAC         1980    NODUPFAC
DATEXP_Austria DATEXP_AUSTRIA 1984    NODUPFAC

WARNINGS

NOFACCHK and NODUPFAC are incompatible and cannot be specifed on the same line.

AUTHOR

x25_networks was developed by HP.

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