Streaming Mode NPMCA.SYS NIC Sleeps on Transmit.

• Microsoft Windows NT Workstation version 3.5 and 3.51
• Microsoft Windows NT Server version 3.5 and 3.51

SYMPTOMS

Under heavy stress situations a WinNT Server with a Network Peripherals Inc. FDDI NIC (NPMCA.SYS) disappears from the network. Performing a NET VIEW \\<Server_Name> command returns Error 53, "Name not found." Existing connections and applications return errors.

CAUSE

When set for "Streaming Mode" the Network Peripherals FDDI NIC goes to sleep under heavy stress. Packets are indicated to the transport and the transport submits packets to the NIC (NPMCA.SYS) but the NIC does not put the packet on the network.

A Network General Sniffer trace during the sleep shows retry traffic to the target, but no responses.

When you set the card to "Normal Mode", it does not exhibit this behavior.

RESOLUTION

To correct this problem, upgrade to Windows NT 3.51 (if you have not already done so) and install the latest U.S. Service Pack for Windows NT version 3.51.

Network Peripherals Inc. provided Microsoft with the fix.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.5 and 3.51. This problem has been corrected in the latest U.S. Service Pack for Windows NT version 3.51. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K