Unwanted Connections Under Windows Xp - Lancom 1751 UMTS Manual

110584_LC-1751-UMTS-MANUAL-EN.book Page 66 Tuesday, February 26, 2008 5:16 PM
LANCOM 1751 UMTS
Chapter 9: Troubleshooting
Increasing the TCP/IP window size under Windows
If the actual transfer rate of a DSL connection is significantly below the fastest
rate listed by the provider, there are only a few possible causes (apart from the
above-mentioned external factors) which may involve one's own equipment.
One common problem occurs when large amounts of data are sent and recei-
ved simultaneously with a Windows PC using an asynchronous connection.
This can cause a severe decrease in download speed. The cause of this pro-
blem is what is known as the TCP/IP receive window size of the Windows ope-
rating system that is set to a value too small for asynchronous connections.
Instructions on how to increase the Windows size can be found in the Know-
ledge Base of the support section of the LANCOM web site (www.lancom.eu).
9.3

Unwanted connections under Windows XP

Windows XP computers attempt to compare their clocks with a timeserver on
the Internet at start-up. This is why when a Windows XP in the WLAN is star-
ted, a connection to the Internet is established by the LANCOM.
To resolve this issue, you can turn off the automatic time synchronization on
the Windows XP computers under Right mouse click on the time of day
Properties
66
Internet time.