Yachts: Ericsson W25 - Enable High Data Rates

The following recommendation comes from the Administrators Guide for the Ericsson W25. It seems to indicate that Windows Vista (and Linux)computers don’t need this to be done.

Enable High Data Rates
Due to the relatively high latency of HSDPA it is necessary to tweak the
TCP/IP stack of the client to achieve maximum performance. The changes
that affect performance the most are enabling TCP Window Scaling and
Selective ACK support.
Most HSDPA PC Card drivers make these settings automatically, but with the
Ericsson W25 they have to be set manually.
Note: Windows Vista and recent versions of Linux kernels have automatic
window scaling enabled by default and should not need any TCP
tweaking.
These kinds of parameters are hidden in the Windows registry, but there are
some tools that give user friendly access to them, for example TCP Optimizer
http://www.speedguide.net/downloads.php
 and DrTCP
http://www.dslreports.com/drtcp
.  

The following settings are recommended to change:
TCP Receive Window = 146000
Selective ACK:s = Yes
Max Duplicate ACK:s = 2
RFC1323 TCP Window Scaling = Yes
Usually (on Windows) it takes more than one TCP session (download) to be
able to fully utilize the HSDPA bandwidth. This means that at least two parallel
TCP sessions should be used when testing maximum throughput.

—

Alan Spicer Telecom / Alan Spicer Marine Telecom

http://www.marinetelecom.net and http://www.wifiyacht.net

+1 954 683 3426

This entry was posted on 5. March 2009 at 21:30 and is filed under Cellular Voice and Internet. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response or trackback from your own site.