Not sure why I am getting this issue, But My Websocket Connection works on specific ISP while fails on others. I know it sounds absurd but it is happening. My websocket connection works on Two ISP while fails on one. I am using Wildfly Application Server serving the WS Connection and Apache WebServer for proxy forwarding.
Here is the detail of my Request/Response,
General
Request URL:ws://example.com/chat/3
Request Method:GET
Status Code:101 Switching Protocols
Response Headers
Connection:Upgrade
Content-Length:0
Date:Fri, 13 May 2016 13:09:11 GMT
Origin:http://example.com
Sec-WebSocket-Accept:pPjTLv5Dz+/vyjY/SkeMihaXDd0=
Sec-WebSocket-Location:ws://example.com/chat/3
Server:WildFly/9
Upgrade:WebSocket
X-Powered-By:Undertow/1
Request Headers
Accept-Encoding:gzip, deflate, sdch
Accept-Language:en-US,en;q=0.8
Cache-Control:no-cache
Connection:Upgrade
Cookie:mp_c4f10660603c33a8e9307b70e6767539_mixpanel=%7B%22distinct_id%22%3A%20%2215210855b11180-0ffdda567-1821170c-d37aa-15210855b123f2%22%2C%22%24initial_referrer%22%3A%20%22%24direct%22%2C%22%24initial_referring_domain%22%3A%20%22%24direct%22%7D; mf_user=a60cd2cdcfc41836645d949f71ee3127; intercom-id=d1af89ac-9d55-4fef-8a17-3848d8ef0fce; wooTracker=VQf16pMBx4Pu; _ga=GA1.2.544774749.1447732319; JSESSIONID=z4a1hBpQJQz4YCsLivHRRFf8b0dzYzBsT_4PLadB.ip-172-30-0-20; mf_154095de-56ef-4099-9976-f9a298cf0677=8438220eda64d856436d798ca0b9188a|05132367e34aabbf7bcce5b1e8811235b0bd15d4|1463144963483||19|
Host:example.com
Origin:http://example.com
Pragma:no-cache
Sec-WebSocket-Extensions:permessage-deflate; client_max_window_bits
Sec-WebSocket-Key:94OH1SxHvszgJO6Rg31WGA==
Sec-WebSocket-Version:13
Upgrade:websocket
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.116 Safari/537.36
However, When I tried testing some of the Demo Sites like http://websocket.org/echo.html they are working as expected.
The only difference I found between those connections was header on response from the server Upgrade:websocket whereas my server is returning Upgrade:WebSocket as part of the response. However, I believe that the header are case insensitive and it shouldn't be the issue.
Also, Is it possible to rewrite the Header value for the Response using apache header mod?