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2600 X.25 pvc connection problem


polling device, understands X.25, talks over IP

polled device, speaks X25, designed to work with modems over serial port

Cisco 2600 series router, used to encapsulate X.25 for IP transmission

Cisco fa0/0 receives calls on specific port from polling device, translates these to pvc on S1/0 connected to polled device.

This is set up with: x25 pvc 1 rbp local port 10001 recordsize 1024 packetsize 512 512 windowsize 3 3


Polled device or router takes serial connection down and up.

This causes the router to send a restart packet (FB) over the pvc. The polled device responds with restart confirm (FF) packet.

Polling device places call to router on port 10001, router routes to polled device, data is successfully polled.

When IP connection is dropped the polled device treats the call like a modem and considers the call disconnected.

It no longer responds to router.

Router sends reset request (1F) packet.

Polled device ignores packet as it considers the link to be in an uninitialized state.

Shutting the serial link down and bringing it back up, or doing an x25 clear causes the exchange of restart packets (FB,FF) and polling is again successful.

However this requires manual intervebntion, where we want an automated process.

How can we cause the router to send the restart packet either at the end odf a successful poll, or the beginning of the next one, or can we?

The polled device has very little configuration.



Re: 2600 X.25 pvc connection problem

All call-related operation failures will also be recorded in a CDR. The information in a CDR for a failed call will include:

Date and time of the call

Call Operation, either a Setup Request or a Disconnect request

Failure Cause Code. These are either the Cause Codes defined in the Q.931 specifications or some codes that are more specific to the DAS Server Shelf and the Dial-Up Frame Relay application. (The next section, Failure/Error Cause Codes, describes the DAS (INS) specific Cause Codes.)

PRI identifier, the local-end DLCI of the PRI D-channel PVC. (This is the DLCI at the DAS Server Shelf.)

Calling Number (ANI), a 20-digit maximum

Called Number 20-digit maximum

Bearer Channel 1 through 24 for T1, or 1 through 31 for E1

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