[c-nsp] PSTN dial backup

[Aaron Riemer]

Hello Cisco Gurus, 

I am having an intermittent dialup problem at the moment that I cant seem to
rectify. I have connected a netcomm modem to the aux port on a Cisco 1751
router for the purpose of gaining access to the device incase the primary
link fails.

The problem is that intermittently I cannot negotiate a connection to the
modem / router when attempting to dial in. Usually the first dial in will
succeed and then subsequent dials will fail. I have tried clearing the line
with 'clear line aux 0' but that seems to have no effect. 

I have reverse telnetted to the modem and I can confirm that the connection
is being made but it times out when attempting to negotiate (usually at the
verifying username and password prompt). 

What I am trying to work out is if this is a line issue or configuration
error? Also would I be correct in assuming that once you configure the modem
with the 'modem autodiscover type <name>' command that the router clears the
current AT settings on the modem and configures the modem accordingly? Would
lowering the baud rate at the modem and the physical interface help if it is
a line issue? i.e. bad attenuation / noise margins? 

Any ideas would be highly appreciated. 

Cheers,

Aaron.