Cabletron Systems CyberSWITCH CSX400 User Manual

Also see for CyberSWITCH HSIM-W6: Setup guide Configuration guide User guide Installation guide

Contents

Troubleshooting the Frame Relay ConnectionLocal Management User’s Guide2-33• Synchronous Polling Messages. The t391 timer for ANSI/ITU Frame Relay forms the basis forpolling between the FR switch and the FR DTE (us). We transmit a STATUS ENQUIRY everyt391 seconds (10 by default) to the FR switch. We expect a STATUS RESPONSE before wereach our next t391 polling cycle. The very first time we transmit a STATUS MESSAGE, andevery successive N391 times (6 by default) we send out a FULL STATUS ENQUIRY. Weexpect a FULL STATUS RESPONSE, which contains information on the DLCIs the switch hasassigned to us. Every other T391 cycle we send out a LINK INTEGRITY VERIFICATIONENQUIRY message (LIV). We expect to get a LINK INTEGRITY VERIFICATIONRESPONSE back from the Fr switch before out t391 polling cycle expires. This is a keep alivemessage that does no more than let us know the link between us and the FR switch is still alive.The information provided in a FULL STATUS RESPONSE, or ASYNCHRONOUS STATUSMESSAGE basically has two parts, the FR Switch provides a DLCI number, and whether thatDLCI is in the Active or Inactive state.• The Active state means that both ends of the connection (this DTE and the DTE at the other endof the WAN cloud) are speaking correctly to the FR DCE Switches in the WAN cloud.• The Inactive state means that either the local or far end DTE is either just starting up and hasnot completed its initial negotiation with the FR Switch, or there is some sort of LMI error. Data(other than LMI negotiation messages) will only be transferred when in the Active state.• A third state value, Invalid, is reported locally only. It is not done by polling the FR switch. Thisis done if the physical connection has some sort of problem. The circuit will remain in theInvalid state until negotiation with the FR DCE Switch completes successfully.FR Error TableThis table is a standard part of RFC 2115, and provides the following information on a physicalinterface per physical interface basis:• The time of the failure: (value of Mib II sysUpTime)• The type of failurereceiveShort: The frame was not long enough to allow demultiplexing - the addressfield was incomplete, or for virtual circuits using Multiprotocol overFrame Relay, the protocol identifier was missing or incomplete.receiveLong: The frame exceeded maximum length configured for this interface.illegalAddress: address field did not match configured format.