NSString *fullURL = [BASE_URL stringByAppendingString:URL];

    // Manager
    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    manager.requestSerializer.timeoutInterval = 30;
    [manager.requestSerializer setAuthorizationHeaderFieldWithUsername:@"userName" password:@"password"];
    manager.responseSerializer.acceptableContentTypes = nil; //[NSSet setWithObjects:@"text/json", @"text/html", nil];

    [manager GET:fullURL parameters:params progress:nil success:^(NSURLSessionDataTask *task, id responseObject) {

        } failure:^(NSURLSessionDataTask *task, NSError *error) {

    }];