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Dial Backup problem

dear all

this is regarding the problem i am facing at one of my customer in india for dial back up configuration using

PSTN line. Following are the list on components used for the configuration

1- 3745 router

2- NM-16AMV2

3- NM-DM30

The PSTN Line terminated on the router are extension served from the EPBAX. In my testing scenario i am trying to initiate callback using local 4 digit extension. Callin is working fine in same scenario.

Pls refer the attachment for the configuration for the same; int async41 i have configured for ppp callback and int fastethernet0/1.40 for testing purpose.

i tried using both ppp callback initiate/accept command to initiate callback. ppp callback accept is used to mscb Microsoft Callback client and ppp callback initiate is used for rfc 1570 compliant client.

During my testing i am able to authenticate the user, as verified form debug output for ppp, but dialup screen on window doesnt proceed further. During this time my int async 41 remains up and the client is unable to obtains any ip address from router as IPCP negotiation phase times out. and then line async 41 remains up indefinently untill i cancel the username and password verifying screen form the windows client.

The chat scripts applied to the interface are no executed either. And their is no option to configure this command script modem-off-hook offhook

which i think is necessary to to take the line offhook so that the router can execute other chat script to initiate call back.

i am attaching the debug output generted for the same, following debugs have been captured

General OS:

Modem control/process activation debugging is on


PPP authentication debugging is on

PPP protocol errors debugging is on

PPP protocol negotiation debugging is on

PPP packet display debugging is on

Chat Scripts:

Chat scripts activity debugging is on


Callback activity debugging is on

VIP Purple

Re: Dial Backup problem


I have made some amendments to your configuration, marked with --> (applies to interface Async41 only), can you test this with Async41, and check if it makes a difference ?



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