Cabletron Systems CSX1000 User Manual

Page 200

USER’S GUIDE

200 CyberSWITCH

Configure the X.25 Reliability, Windows, and Acknowledgment Facilities.
a.

Select the type of sequence numbers to be used for X.25: regular or extended. Extended
sequence numbering allows for packets to be assigned sequence numbers from 0-127
(modulo 128), as opposed to 0-7 (modulo 8).

Enter the Maximum Window Size. This is the largest possible window size to be supported
on any virtual circuit. SVCs that support window size negotiation will never allow the
agreed upon window size to exceed this value. If regular (modulo 8) sequence numbers are
being used, the range of possible window sizes is 1-7. If extended (modulo 128) sequence
numbers are being used, the range of possible window sizes is 1-127.

Select the Maximum Packet Size. This value is used to determine the maximum packet size
that the system will support for X.25 connections. When packet size negotiation is
performed on SVCs, this value will be used as the upper bound.

Configure the X.25 Quality-of-Service Facilities for SVCs.
The first three items are configured for SVCs that can perform negotiation.
a.

Select the Maximum Throughput Class. This value is used to determine the maximum
throughput class that the system will support for X.25 connections. When throughput class
negotiation is performed on SVCs, this value will be used as the upper bound.

Choose whether Flow Control Negotiation is to be supported for SVCs (negotiation is not
performed on PVCs).

Choose whether Throughput Class Negotiation is to be supported for SVCs (negotiation is
not performed on PVCs).

The next 6 items configured are the nonstandard default parameters for SVCs that do not
support negotiation. These parameters are used on SVCs that do not use the standard X.25
values, but also do not support any facility negotiation.

d. Enter the Nonstandard Default Transmit Window Size. The range of allowable values for

this parameter is based upon configured sequence number modulus (1-7 for Modulo 8, and
1-127 for Modulo 128).

Enter the Nonstandard Default Receive Window Size.

Select the Nonstandard Default Transmit Packet Size.

Select the Nonstandard Default Receive Packet Size.

h. Select the Nonstandard Default Transmit Throughput Class.
i.

Select the Nonstandard Default Receive Throughput Class.

Configure the X.25 Charging-Related Facilities.
a.

Choose whether the system should accept incoming X.25 calls that request reverse
charging.

Choose whether outgoing X.25 calls should request reverse charging.

Configure the X.25 Restriction Facilities. These facilities are used to place restrictions upon
incoming and outgoing X.25 calls.
a.

Choose whether incoming calls should be barred.

Choose whether outgoing X.25 calls should be barred.

Configure the X.25 Miscellaneous Facilities.
a.

Choose whether fast select acceptance should be done on incoming calls.

Choose whether fast select should be done on outgoing calls.

After all of the X.25 facilities have been specified, you may configure virtual circuits.

This manual is related to the following products:

CSX1200