[MSDN Library June 1998] PPTP Connection is Slow (66.0711981269473%)
MSDN Library Visual Studio 6.0 > Windows Resource Kits > Windows NT Server 4.0 Resource Kit > Windows NT Server Resource Kit - Supplement 2 > Troubleshooting PPTP on Microsoft Clients > Troubleshooting PPTP on a Windows NT-based PPTP Client