A lentidão pode ser devida à opção de escala da janela TCP .
O artigo Receive Window Auto -Tuning no Vista diz o seguinte:
If your connection from a Vista machine appears slow or hung, here are some steps to isolate the cause:
- First, make sure that your firewall and router can support window scaling. You can check with the manufacturer or run the connectivity diagnostic suite (especially, TCP High Performance Test) provided by Microsoft to determine your gateway device’s compliance.
- Second, check with the manufacturer if a firmware update has been issued for your device that can fix the problem.
- Third, If the problem still persists, you can restrict autotuning by running “netsh interface tcp set global autotuninglevel=restricted” from the command prompt. We have found that restricted mode will often allow some of the benefits of autotuning with a number of problematic devices.
- Lastly, if all else fails, in order to disable this feature, run "netsh interface tcp set global autotuninglevel=disabled".
- (In order to reenable autotuning, run “netsh interface tcp set global autotuninglevel=normal”.)