Dial-Up Networking usually requires the same modem driver to be installed on the NetModem Client as is installed on NetModem Server. For example if the Modem Server PC is using the manufactures modem driver, then the client typically should NOT use a Windows "Standard 56k" modem driver.

If you are unable to get Dial-Up networking to work, and you are using matching modem drivers, the first thing to do is check that you are able to sucessfully dial the same phone number using Hyperterminal that you intend to use for Dial-Up Networking.

 

	NetModem Client is properly installed and configured.
	NetModem Server is properly installed and configured.
	The Modem(s) are properly installed and configured.
	The phone number being dialed is correct, and the remote location being dialed is answering.

Once you have confirmed that that all these things have been tested, it narrows down the cause to being a configurationissues with Dial-Up Networking itself. Make sure the network settings are correct, such as the username/password being entered correctly (these are usually case sensitive).

If you get strange network behavior when you attempt to use Dial-Up Networking over NetModem Client. 

If some servers on the LAN become inaccessible or you get messages about being logged off the network, it could be due to the fact that that  Dial-Up Networking causes a new "default route" to be added to the routing table once a successful session is initiated. If the local LAN contains multiple subnets, and the PC gains access to those subnets using a default route in the routing table, the new default route added by Dial-Up Networking will supercede the original. This has the effect of allowing access to only the local subnet, because packets destined for the other subnets will be routed to the modem rather than the network card.

This problem is not specific to NetModem Client and occurs on any PC using a local modem as well. The Microsoft KnowledgeBase contains the following articles concerning this issue:

https://support.microsoft.com/kb/138878

https://support.microsoft.com/kb/128647

The articles only mention NT and RAS, but they are equally applicable to all versions of Windows running Dial-Up Networking or RAS.


More information and how to add a non-default route to your routing table

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