Troubleshooting: Winsock Performance Test Shows UDP Packets Not Received (Windows CE 5.0)
Description
When you use the Winsock Performance Test to measure the performance of a gateway, UDP-related test cases including the UDP Ping test case indicate that packets fail to cross the gateway or indicate that the round trip time is zero.
Resolution
The Winsock Performance Test relies on port numbers that are not translated. If a target device, such as a gateway, uses network address translation (NAT), a TCP or User Datagram Protocol (UDP) port on the private side of the gateway is translated when one of the following conditions is met:
Another client uses the port number for the port.
To avoid conflicts with other clients, on the test network do not run anything except the hardware and software required by the Winsock Performance Test.
The port number is outside of the range of port numbers that are not translated.
For a Windows CE–based gateway, the default range of port numbers that are not translated is 1025 to 3000, inclusive. The Winsock Performance Test expects ports in the range of 1024 to 5000, inclusive, to be not translated. If you are testing a Windows CE–based gateway, use the following registry settings to extend the reserved port range.
[HKEY_LOCAL_MACHINE\Comm\IPNat] "ReservedPortsStart"=DWORD:400 "ReservedPortsEnd"=DWORD:1388
See Also
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