iOS Strange log NETAWDManager

Question

With iOS 9 i see in my iPhone console strange logs

These logs appears when the app connected to remote service,and maybe when the connection is slow, i use NSURLSession. Someone has an idea about the meaning of this log, should I care of this:

-[NETAWDManager reportStats:metricID:] server 0x13cd19d70, container 0x13ce9dfe0, metrid 2686983, successfully reported:
<AWDLibnetcoreTCPConnectionReport: 0x13ce7af10> {
    cellularFallbackReport =     {
        dataUsageSnapshotsAtNetworkEvents =         (
                        {
                bytesIn = 0;
                bytesOut = 410;
            }
        );
        "fallbackTimer_msecs" = 0;
        fellback = 0;
        networkEvents =         (
            "NETWORK_EVENT_DATA_STALL_AT_APP_LAYER"
        );
        "timeToNetworkEvents_msecs" =         (
            3325
        );
    };
    clientIdentifier = "com.mydomain.myapp";
    connectionStatisticsReport =     {
        DNSAnswersCached = 1;
        "DNSResolvedTime_msecs" = 3;
        RTTvariance = 169;
        "appDataStallTimer_msecs" = 3;
        appReportingDataStallCount = 1;
        "bestRTT_msecs" = 359;
        betterRouteEventCount = 0;
        bytesDuplicate = 0;
        bytesIn = 37000;
        bytesOut = 410;
        bytesOutOfOrder = 0;
        bytesRetransmitted = 0;
        cellularFallback = 0;
        cellularRRCConnected = 0;
        connected = 1;
        connectedInterfaceType = "INTERFACE_TYPE_WIFI";
        "connectionEstablishmentTime_msecs" = 308;
        connectionReuseCount = 0;
        "currentRTT_msecs" = 79;
        "flowDuration_msecs" = 30750;
        interfaceType = "INTERFACE_TYPE_WIFI";
        kernelReportedStalls = 0;
        kernelReportingConnectionStalled = 0;
        kernelReportingReadStalled = 0;
        kernelReportingWriteStalled = 0;
        packetsDuplicate = 0;
        packetsIn = 26;
        packetsOut = 1;
        packetsOutOfOrder = 0;
        packetsRetransmitted = 0;
        "smoothedRTT_msecs" = 275;
        synRetransmissionCount = 0;
        tcpFastOpen = 0;
        "timeToConnectionEstablishment_msecs" = 315;
        "timeToConnectionStart_msecs" = 7;
        "timeToDNSResolved_msecs" = 7;
        "timeToDNSStart_msecs" = 4;
        trafficClass = 0;
    };
    delegated = 0;
    reportReason = "REPORT_REASON_DATA_STALL_AT_APP_LAYER";
}

Answer 1

Based on the identifier cellularFallbackReport, this message may be related WiFi Assist. It's a new feature in iOS 9 that detects slow WiFi connections and automatically falls back to the phone's cellular radio.

This would be consistent with your observation that the log message occurs when you have a slow connection.

If you're able to reproduce the message reliably, try disabling WiFi Assist in settings and see if it disappears:

If that's really what it is, should you care about it? Probably not. The messages indicate the iOS system is dealing with network problems automatically on behalf of your app, and there's not much you can do about it.