diff --git a/QiniuSDK/Http/QNHttpManager.m b/QiniuSDK/Http/QNHttpManager.m
index aef1e12d..1d8c0f9e 100644
--- a/QiniuSDK/Http/QNHttpManager.m
+++ b/QiniuSDK/Http/QNHttpManager.m
@@ -18,14 +18,8 @@ @interface QNHttpManager ()
 @property (nonatomic) AFHTTPRequestOperationManager *httpManager;
 @end
 
-static NSString *userAgent = nil;
-
 @implementation QNHttpManager
 
-+ (void)initialize {
-	userAgent = QNUserAgent();
-}
-
 - (instancetype)init {
 	if (self = [super init]) {
 		_httpManager = [[AFHTTPRequestOperationManager alloc] init];
@@ -41,14 +35,17 @@ + (QNResponseInfo *)buildResponseInfo:(AFHTTPRequestOperation *)operation
                          withResponse:(id)responseObject {
 	QNResponseInfo *info;
 	NSString *host = operation.request.URL.host;
-//    NSArray *hostIp = [QNDns getAddresses:host];
 
 	if (operation.response) {
 		NSDictionary *headers = [operation.response allHeaderFields];
 		NSString *reqId = headers[@"X-Reqid"];
 		NSString *xlog = headers[@"X-Log"];
+		NSString *xvia = headers[@"X-Via"];
+		if (xvia == nil) {
+			xvia = headers[@"X-Px"];
+		}
 		int status =  (int)[operation.response statusCode];
-		info = [[QNResponseInfo alloc] init:status withReqId:reqId withXLog:xlog withHost:host withDuration:duration withBody:responseObject];
+		info = [[QNResponseInfo alloc] init:status withReqId:reqId withXLog:xlog withXVia:xvia withHost:host withDuration:duration withBody:responseObject];
 	}
 	else {
 		info = [QNResponseInfo responseInfoWithNetError:error host:host duration:duration];
@@ -69,10 +66,12 @@ - (void)  sendRequest:(NSMutableURLRequest *)request
 	    if (info.isOK) {
 	        resp = responseObject;
 		}
+	    NSLog(@"success %@", info);
 	    completeBlock(info, resp);
 	}                                                                failure: ^(AFHTTPRequestOperation *operation, NSError *error) {
 	    double duration = [[NSDate date] timeIntervalSinceDate:startTime];
 	    QNResponseInfo *info = [QNHttpManager buildResponseInfo:operation withError:error withDuration:duration withResponse:operation.responseData];
+	    NSLog(@"failure %@", info);
 	    completeBlock(info, nil);
 	}
 
@@ -85,7 +84,7 @@ - (void)  sendRequest:(NSMutableURLRequest *)request
 	}
 	[request setTimeoutInterval:kQNTimeoutInterval];
 
-	[request setValue:userAgent forHTTPHeaderField:@"User-Agent"];
+	[request setValue:QNUserAgent() forHTTPHeaderField:@"User-Agent"];
 	[request setValue:nil forHTTPHeaderField:@"Accept-Language"];
 	[_httpManager.operationQueue addOperation:operation];
 }
diff --git a/QiniuSDK/Http/QNResponseInfo.h b/QiniuSDK/Http/QNResponseInfo.h
index 7a3d7594..73973fea 100644
--- a/QiniuSDK/Http/QNResponseInfo.h
+++ b/QiniuSDK/Http/QNResponseInfo.h
@@ -48,6 +48,11 @@ extern const int kQNFileError;
  */
 @property (nonatomic, copy, readonly) NSString *xlog;
 
+/**
+ *    cdn服务器内部跟踪记录
+ */
+@property (nonatomic, copy, readonly) NSString *xvia;
+
 /**
  *    错误信息，出错时请反馈此记录
  */
@@ -69,9 +74,9 @@ extern const int kQNFileError;
 @property (nonatomic, readonly) NSString *serverIp;
 
 /**
- *    服务器IP
+ *    网络类型
  */
-@property (nonatomic, readonly) NSString *networkType;
+//@property (nonatomic, readonly) NSString *networkType;
 
 /**
  *    是否取消
@@ -152,6 +157,7 @@ extern const int kQNFileError;
 - (instancetype)init:(int)status
            withReqId:(NSString *)reqId
             withXLog:(NSString *)xlog
+            withXVia:(NSString *)xvia
             withHost:(NSString *)host
         withDuration:(double)duration
             withBody:(NSData *)body;
diff --git a/QiniuSDK/Http/QNResponseInfo.m b/QiniuSDK/Http/QNResponseInfo.m
index 99ea4e10..6f1c5be7 100644
--- a/QiniuSDK/Http/QNResponseInfo.m
+++ b/QiniuSDK/Http/QNResponseInfo.m
@@ -73,6 +73,7 @@ - (instancetype)initWithStatus:(int)status
 - (instancetype)init:(int)status
            withReqId:(NSString *)reqId
             withXLog:(NSString *)xlog
+            withXVia:(NSString *)xvia
             withHost:(NSString *)host
         withDuration:(double)duration
             withBody:(NSData *)body {
@@ -80,6 +81,7 @@ - (instancetype)init:(int)status
 		_statusCode = status;
 		_reqId = [reqId copy];
 		_xlog = [xlog copy];
+		_xvia = [xvia copy];
 		_host = [host copy];
 		_duration = duration;
 		if (status != 200) {
@@ -105,7 +107,7 @@ - (instancetype)init:(int)status
 }
 
 - (NSString *)description {
-	return [NSString stringWithFormat:@"<%@: %p, status: %d, requestId: %@, xlog: %@, host: %@ duration:%f s serverIp:%@ error: %@>", NSStringFromClass([self class]), self, _statusCode, _reqId, _xlog, _host, _duration, _serverIp, _error];
+	return [NSString stringWithFormat:@"<%@: %p, status: %d, requestId: %@, xlog: %@, xvia: %@, host: %@ duration:%f s serverIp:%@ error: %@>", NSStringFromClass([self class]), self, _statusCode, _reqId, _xlog, _xvia, _host, _duration, _serverIp, _error];
 }
 
 - (BOOL)isCancelled {