HP X.25/9000 Programmer's Guide

92 Chapter6
Extended Features
Using Facilities
The facilities supported for ioctl(X25_WR_FACILITIES) are those
specified in the CCITT and X.25 (1988) recommendation. These include:
• Flow Control Parameter Negotiation – if your configuration
specifies that flow control negotiation is ON and Flow Control
facilities are not requested with the ioctl(X25_WR_FACILITIES)
call, your default values for Packet Size and Window Size facilities
are inserted in the packet.
• Throughput class negotiation – not inserted in the packet unless
it is requested and there is no default configured.
• Fast Select /Reverse Charging – not inserted in the call or call
accepted packet if 0x0100 is requested (neither fast select or reverse
charging is requested).
• Charging information requesting service – if 0x0400 is
requested, no charging information is inserted in the call or call
accepted packet.
• RPOA Selection extended format – if only one DNIC is specified,
the ioctl(X25_WR_FACILITIES) returns an error (errno EINVAL=22).
Use the basic format instead. The extended format is only available if
more than one DNIC is specified.
• Transit Delay Selection – this facilities is used to request a specific
end-to-end transit delay (a Packet Layer Protocol function). If
present, the value is based on the actual end-to-end transit time
(minus the system processing time).
• End-to-End Transit Delay Selection – this facilities overrides the
Transit Delay Selection parameter (above) with a constant
corresponding to the system’s data processing time. The requested
end-to-end transit delay and maximum acceptable end-to-end transit
delay values are sent without modification to packets. If this is the
only parameter provided and the Transit Delay Selection parameter
is not requested, no information is inserted in the packet.
• Expedited Data Negotiation – not inserted in the packet if
requested after a 0x0b00 marker.
• Network Facilities – these facilities must have a facility marker
just before them.
Network Facilities
Network facilities need a facility marker just before them. The only legal
36960-90061.bk Page 92 Friday, November 10, 2000 3:42 PM