Strange network related 417 'expectation failed' error when consuming webservice.

[etienne_marais]

Hi

My windows forms c# application consuming a webservice seems to work fine when I run both from the IDE (VS 2010).

When I publish the webservice to a server at an ISP, I get a '417 Expectation Failed' when trying to call a webservice method when using our internet access via our internal wireless network.

But when I use my LTE modem for internet access the application works fine. Hence network related.

The 417 error is usually associated with proxies according to what I have googled, but we do not use any proxies PLUS the error only appeared recently after several successful launches. I am thinking that it is related to the webservice and network in combination, i.e. the SOAP packet have reached a threshold and the network configuration is such that the packets can't be communicated ?

Please help

 

[etienne_marais]

( I'm already using:

BasicHttpBinding binding = new BasicHttpBinding();
binding.MaxReceivedMessageSize = 2147483647;
binding.MaxBufferSize = 2147483647;

)

 

[GoofySmurf]

Hi

My windows forms c# application consuming a webservice seems to work fine when I run both from the IDE (VS 2010).

When I publish the webservice to a server at an ISP, I get a '417 Expectation Failed' when trying to call a webservice method when using our internet access via our internal wireless network.

But when I use my LTE modem for internet access the application works fine. Hence network related.

The 417 error is usually associated with proxies according to what I have googled, but we do not use any proxies PLUS the error only appeared recently after several successful launches. I am thinking that it is related to the webservice and network in combination, i.e. the SOAP packet have reached a threshold and the network configuration is such that the packets can't be communicated ?

Please help

They are routing your traffic through a proxy and the proxy is blocking it. Currently this practice is illegal in the country, by law you are not allowed to block anything without a court order if your a ISP.

 

[etienne_marais]

Thanks GoofySmurf, probably not much I can do about it (?), and to make things worse there may be some end-users who will have the same problem when they switch to ISP's who does something similar

 

[etienne_marais]

Resolved with: System.Net.ServicePointManager.Expect100Continue = false;

But is it safe ?