Bad performance on Web Service call

[Werner Willemsens]

Hi,

I have the following situation. COM server exposed on Windows CE 5.0 through
SOAP (SOAP toolkit)
C# client on XP calls Web Service methods on CE (COM)SOAP server.
The complete call takes 527msec. Why is it so much?
The SOAP method call is very simple : a COM method with 1 argument (long)
The Ethereal logging shows that the CE server side responsiveness is good,
but the XP C# client waits a very long time before he gives an ack
on the previous TCP message initiated by the CE server.
Why does it take so long on the XP side to give the acknowledge? This makes
the SOAP implementation VEEERRRYYY slow compared to for example DCOM. I can
make the same call with DCOM in less than 2msec.

CE side = Pentium M 1.3Ghz, Windows CE 5.0
XP side = Pentium 4 2.66Ghz, Windows XP Pro SP2, .NET 2.0, WSE 3 installed
I am not using any authentication (anonymous) or security

Ethereal trace
1 0.000000 192.168.2.40 -192.168.2.48 TCP [TCP segment of a reassembled
PDU]
2 0.119940 192.168.2.48 -192.168.2.40 TCP http 1442 [ACK] Seq=0
Ack=307 Win=32406 Len=0
3 0.119968 192.168.2.40 -192.168.2.48 HTTP POST /GateWS.wsdl HTTP/1.1
4.0.120142 192.168.2.48 -192.168.2.40 TCP http 1442 [ACK] Seq=0
Ack=867 Win=32580 Len=0
5 0.120677 192.168.2.48 -192.168.2.40 TCP [TCP segment of a reassembled
PDU]
6 0.309083 192.168.2.40 -192.168.2.48 TCP 1442 http [ACK] Seq=867
Ack=185 Win=64842 Len=0
7 0.309211 192.168.2.48 -192.168.2.40 HTTP HTTP/1.0 200 OK
8 0.527824 192.168.2.40 -192.168.2.48 TCP 1442 http [ACK] Seq=867
Ack=508 Win=64519 Len=0

CE server = 192.168.2.48
XP client = 192.168.2.40

1 = Initial call from client to server "POST /GateWS.wsdl"
2 = Acknowledge of message 1 by server
3 = Call SOAP method
4 = Acknowledge of message 3 by server
5 = "HTTP1.0 200 OK"
6 = Acknowledge of message 5 by client
7 = SOAP call response
8 = Acknowledge of message 7 by client
Werner