Cabletron Systems Cabletron CyberSWITCH CSX5500 User Manual

Also see for CyberSWITCH 5500: Quick start Manual

Contents

Central Site Remote Access Switch 245CONFIGURING A LTERNATE ACCESSESX.25 Accesses4. Enter the X.121 address of the local DTE (the CyberSWITCH).5. Select the data rate for the line.6. Enter a list of bearers (a channel map). For PRI lines, the range of channels is from 1 to 24. ForBRI lines, the range of channels is from 1 to 2. Separate bearer channels by commas, and/or lista range by using a dash (-).LAPB C ONFIGURATION INFORMATION1. Enter the LAPB sequence number range to use, regular, or extended. Extended sequencenumbering allows for frames to be assigned sequence numbers from 0-127 (modulo 128), asopposed to 0-7 (modulo 8).2. Enter the duration of Timer T1, which is the maximum time to wait for responses to pendingcommands.3. Enter the duration of Timer T3, which is used to signal that an excessively long idle time isoccurring on the link. LAPB requires that Timer T3 be greater than Timer T1.4. Enter the maximum number of frame re-transmissions that can be performed (this iscommonly known as “N2”).5. Enter the maximum number of frames that the transmitting station may have outstanding atany given time (this is commonly known as “K”). The range for this parameter will be 1-7 if theModulo 8 sequence numbers are being used for LAPB, or 1-127 if Modulo 128 sequencenumbers are being used.X.25 C ONFIGURATION I NFORMATION1. Configure the X.25 Logical Channel Assignments. This requires entering the maximumnumber of PVCs and SVCs to be supported. For X.25 over B-channel, a total of 48 virtualcircuits are supported; over D-channel 8 virtual circuits are supported. Therefore, the totalnumber of PVCs and SVCs combined cannot exceed the maximum number of VCs.a. Enter the maximum number of PVCs to support.b. Enter the maximum number of SVCs to support.2. Configure the X.25 Timers.a. Enter the duration of Timer T20.This timer designates the time limit in which a restart confirmation must be returned by theDCE (the PPSN) after a restart request has been issued by the DTE (the CyberSWITCH).b. Enter the duration of Timer T21.This timer designates the time limit in which a call connected response must be returnedby the DCE (the PPSN) after a call request has been issued by the DTE (the CyberSWITCH).c. Enter the duration of Timer T22.This timer designates the time limit in which a reset confirmation must be returned by theDCE (the PPSN) after a reset request has been issued by the DTE (the CyberSWITCH).d. Enter the duration of Timer T23.This timer designates the time limit in which a clear confirmation must be returned by theDCE (the PPSN) after a clear request has been issued by the DTE (the CyberSWITCH).