ios - _kCFStreamErrorCodeKey=-2102 only with wifi of some ISPs

Question

I use below code to send a file to the server:

NSString *urlString = [NSString stringWithFormat:@"%@%@",[LIUtility sharedUtility].uploadConnectionURL,BR_SERVER_UPLOAD_ADDRESS_FILE];

self.request =[[NSMutableURLRequest alloc] init];
[self.request setURL:[NSURL URLWithString:urlString]];
[self.request setHTTPMethod:@"POST"];

PKMultipartInputStream *body = [[PKMultipartInputStream alloc] init];

NSString *requestString =[self getRequestStringForRange:range andExtension:fileName];
NSData *requestData = [requestString dataUsingEncoding:NSUTF8StringEncoding];

NSString *jsonLengthString = [NSString stringWithFormat:@"%04lu",(unsigned long)requestData.length];
NSData *jsonLengthData = [jsonLengthString dataUsingEncoding:NSUTF8StringEncoding];

[body addPartWithName:@"jsonLength" data:jsonLengthData];
[body addPartWithName:@"json" data:requestData];
[body addPartWithName:@"separator" string:@"
"];
[body addPartWithName:@"fileData" filename:fileName stream:dataStream streamLength:streamSize];

[self.request setHTTPBodyStream:body];
[self.request setTimeoutInterval:60];
NSString *contentType = LI_CONNECTION_CONTENTTYPE;
[self.request addValue:contentType forHTTPHeaderField: @"Content-Type"];

self.connection = [[NSURLConnection alloc] initWithRequest:self.request delegate:self];
_responseData = [NSMutableData data];
[self.connection start];

The file is uploading with 3G/4G.The code also works when device is connected to wifi of some ADSL ISPs but in some other ISPs the code do not work and I get below error:

Error Domain=NSURLErrorDomain Code=-1001 "The request timed out." UserInfo={NSErrorFailingURLStringKey=http://example.net, _kCFStreamErrorCodeKey=-2102, NSErrorFailingURLKey=http:/example.net:80/au, NSLocalizedDescription=The request timed out., _kCFStreamErrorDomainKey=4, NSUnderlyingError=0x16a40410 {Error Domain=kCFErrorDomainCFNetwork Code=-1001 "The request timed out." UserInfo={_kCFStreamErrorCodeKey=-2102, NSErrorFailingURLStringKey=http://example.net, NSErrorFailingURLKey=http://example.net, NSLocalizedDescription=The request timed out., _kCFStreamErrorDomainKey=4}}}

Does anyone have any idea about what is the problem?

Answer 1

I finally solved my problem by adding Content-Length to the request.

When we do not add the Content-Length header to the request, NSURLConnection send it as a chunked request and it seems such problems is common with chunked requests.

Actually I do not found the root cause of the problem with this chunked request (I searched many subjects in web, reads many articles, talked with several other programmers but do not find any root cause, so I decide to use the other solution ) but I shared this solution for someone that can use non-chunked request in their business. As I know most usages of chunked requests are in real time streaming that we do not know the Content-Length so if you can add Content-Length, I suggest to use it for avoiding chunked problems like this.