Cabletron Systems Cabletron CyberSWITCH CSX5500 User Manual

Also see for CyberSWITCH 5500: Quick start Manual

Contents

USER’S GUIDE246 CyberSWITCH3. 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. Extendedsequence numbering allows for packets to be assigned sequence numbers from 0-127(modulo 128), as opposed to 0-7 (modulo 8).b. Enter the Maximum Window Size. This is the largest possible window size to be supportedon any virtual circuit. SVCs that support window size negotiation will never allow theagreed upon window size to exceed this value. If regular (modulo 8) sequence numbers arebeing used, the range of possible window sizes is 1-7. If extended (modulo 128) sequencenumbers are being used, the range of possible window sizes is 1-127.c. Select the Maximum Packet Size. This value is used to determine the maximum packet sizethat the system will support for X.25 connections. When packet size negotiation isperformed on SVCs, this value will be used as the upper bound.4. 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 maximumthroughput class that the system will support for X.25 connections. When throughput classnegotiation is performed on SVCs, this value will be used as the upper bound.b. Choose whether Flow Control Negotiation is to be supported for SVCs (negotiation is notperformed on PVCs).c. Choose whether Throughput Class Negotiation is to be supported for SVCs (negotiation isnot performed on PVCs).The next 6 items configured are the nonstandard default parameters for SVCs that do notsupport negotiation. These parameters are used on SVCs that do not use the standard X.25values, but also do not support any facility negotiation.d. Enter the Nonstandard Default Transmit Window Size. The range of allowable values forthis parameter is based upon configured sequence number modulus (1-7 for Modulo 8, and1-127 for Modulo 128).e. Enter the Nonstandard Default Receive Window Size.f. Select the Nonstandard Default Transmit Packet Size.g. Select the Nonstandard Default Receive Packet Size.h. Select the Nonstandard Default Transmit Throughput Class.i. Select the Nonstandard Default Receive Throughput Class.5. Configure the X.25 Charging-Related Facilities.a. Choose whether the system should accept incoming X.25 calls that request reversecharging.b. Choose whether outgoing X.25 calls should request reverse charging.6. Configure the X.25 Restriction Facilities. These facilities are used to place restrictions uponincoming and outgoing X.25 calls.a. Choose whether incoming calls should be barred.b. Choose whether outgoing X.25 calls should be barred.7. Configure the X.25 Miscellaneous Facilities.a. Choose whether fast select acceptance should be done on incoming calls.b. 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.