Microsoft KB Archive/139740

= Microsoft Knowledge Base =

Slow Performance with Sierra Semiconductor Chip Set Modem
Last reviewed: October 7, 1997

Article ID: Q139740

The information in this article applies to:


 * The Microsoft Network versions 1.0, 1.05, 1.2, 1.3, 2.0, 2.5

SYMPTOMS
When you are using a modem with a Sierra Semiconductor chip set, you can connect to MSN, The Microsoft Network, but it may take a long time to display a new window and its contents, even though the modem icon on the taskbar shows a nearly continuous green light that indicates that data is being received.

CAUSE
This behavior occurs with modems with a Sierra Semiconductor 14,400 bps chip set. Modems used by MSN contain the Rockwell chip set. The Sierra Semiconductor 14,400 bps chip set is not fully compatible with the Rockwell chip set.

RESOLUTION
To work around this behavior, follow these steps:


 * 1) Click Start, point to Settings, and then click Control Panel.
 * 2) Double-click Modems.
 * 3) On the General tab, click your modem, and then click Properties.
 * 4) On the General tab, click 57600 (or 115200 if it is available) in the Maximum Speed box.
 * 5) On the Connection tab, click Advanced.
 * 6) Click the Use Error Control check box to clear it.
 * 7) Click OK or Close until you return to Windows.

These settings cause the computer to access the modem's FIFO buffers as fast as possible, and reduce the chip set's workload by reducing the compression and error-correction overhead.

If performance remains unacceptably slow, the only solution is to purchase a modem using a Rockwell-compatible chip set.