SBS: Network Connectivity Unavailable for Windows NT-Based RAS Clients with Fax Enabled

ID: Q241807

The information in this article applies to:

Microsoft BackOffice Small Business Server version 4.5

SYMPTOMS

After your Microsoft Windows NT-based client computer connects to a Small Business Server 4.5-based Remote Access Service (RAS) server and receives an Internet Protocol (IP) address, network connectivity may become unavailable. For example, you may be unable to ping the server by name or IP address.

CAUSE

This issue can occur if you are using a 3COM/US Robotics Courier V.Everything modem that is configured to receive incoming faxes and also receive incoming RAS calls. Some firmware versions of the 3COM/US Robotics Courier V.Everything modems do not work correctly in this configuration.

RESOLUTION

To resolve this issue, contact 3COM/US Robotics to inquire about the availability of a fix for this issue.

To work around this issue when the fax service is used, it is recommended to dedicate one modem to process both incoming and outgoing faxes to isolate incoming fax calls from incoming RAS calls. To disable incoming faxes:

On the RAS server, click Start, point to Settings, click Control Panel, and then double-click Fax Server.

Click on the Receive tab, and then click to clear the check box for the modem that will be used for RAS calls.

NOTE: If isolating a fax modem is not possible, the fax strings for the modem must be updated to work with the specific modem firmware. The modems should be removed and reinstalled with the updated Unimodem.inf file, and the fax service should be removed and reinstalled with the updated modem strings.

MORE INFORMATION

The following keys were changed in the [Courier] heading of MDMCRV90.INF:


HKR,Fax\Class1\AdaptiveAnswer\AnswerCommand, 1,, "AT+FCLASS=1" 
HKR,Fax\Class1\AdaptiveAnswer\AnswerCommand, 2,, "AT&B1&C1&D2E0Q0V1&A3S0=0" 
HKR,Fax\Class1\AdaptiveAnswer\AnswerCommand, 3,, "ATS7=60S19=0M1&M4&K1&H1&R2&I0B0X4" 
HKR,Fax\Class1\AdaptiveAnswer\AnswerCommand, 4,, "AT+FAA=1" 
HKR,Fax\Class1\AdaptiveAnswer\AnswerCommand, 5,, "ATA"

Additional query words: smallbiz

Keywords : kbhw kbnetwork dun wincomm
Version : winnt:4.5
Platform : winnt
Issue type : kbprb