Troubleshooting guide

Cingular Communication Manager Settings
95
The TCP Receive Window (also known as RWIN) specifies the maximum
amount of data that another system may send before it receives an
acknowledgement for at least some of the data sent previously. When this
value is set too high, the sending system may transmit far more
information than your current Internet connection can actually receive in a
given period of time. This could result in lost information that the sender
has to retransmit (causing delays). If the value is set too low, the sender is
spending more time waiting for your system's acknowledgements than it
needs to and less time sending information to you (this can also cause
delays).
Since the optimal value for RWIN varies depending on the speed of the
network to which your system is connected, the value can be set
independently for most types of connections. When you install a new
network adapter (or wireless modem), the installer program will usually
optimize the RWIN value for its type of connection. So, for the vast
majority of connection types, you never need to worry about this value.
However, your PC also has a Global RWIN valueEthat may be used in
certain circumstances Ethe most common being when you establish a
VPN connection (depending on the specific VPN make). The RWIN settings
provided on the Advanced Networking settings tab adjust this global
value. However, you should only adjust them if you are specifically
instructed to do so by your network administrator.
Use custom value
Selecting this option allows you to specify a custom global RWIN value in
the space provided.
Optimized Wireless Data Value
Selecting this option sets the global RWIN value to an optimized value
specified by Cingular (if any).
Use default OS value
Selecting this option keeps the global RWIN value at its default setting for
your operating system. It is strongly recommended that this option is
selected unless you are specifically instructed to do otherwise by your
network administrator.