Implicit chunk serialization

Question

I'm currently trying to simulate a little cognitive radio network with omnet++ using primary/secondary sender/receiver nodes. To make it work, I had the idea of configuring the primary sender as a node that talks whenever it wants and configuring the secondary send as a node that uses the CSMA protocol of the Inet framework. But when I launch the simulation, I get the following message as soon as the secondary sender tries to send a packet:

Implicit chunk serialization is disabled to prevent unpredictable performance degradation (you may consider changing the Chunk::enableImplicitChunkSerialization flag or passing the PF_ALLOW_SERIALIZATION flag to peek) -- in module (inet::AckingMac) CR_test.PU.wlan[0].mac (id=52), at t=0.012541991668s, event #28

Does somebody knows how to overcome this issue?

Here is my .ini file :

[General]

network = CR_test
sim-time-limit = 1s

*.**.ipv4.arp.typename = "GlobalArp"

*.PU.numApps = 1
*.PU.app[0].typename = "UdpBasicApp"
*.PU.app[0].destAddresses = "ReceptorPU"
*.PU.app[0].destPort = 5000
*.PU.app[0].messageLength = 1000B
*.PU.app[0].sendInterval = exponential(10ms)
*.PU.app[0].packetName = "UDPData"

*.SU.numApps = 1
*.SU.app[0].typename = "UdpBasicApp"
*.SU.app[0].destAddresses = "ReceptorSU"
*.SU.app[0].destPort = 6000
*.SU.app[0].messageLength = 1000B
*.SU.app[0].sendInterval = exponential(10ms)
*.SU.app[0].packetName = "UDPData"

*.ReceptorPU.numApps = 1
*.ReceptorPU.app[0].typename = "UdpSink"
*.ReceptorPU.app[0].localPort = 5000

*.ReceptorSU.numApps = 1
*.ReceptorSU.app[0].typename = "UdpSink"
*.ReceptorSU.app[0].localPort = 6000

*.**.**.bitrate = 1Mbps

*.ReceptorSU.wlan[0].typename = "WirelessInterface"                             ## With CSMA
*.ReceptorSU.wlan[0].radio.typename = "UnitDiskRadio"
*.ReceptorSU.wlan[0].mac.typename = "CsmaCaMac"

*.SU.wlan[0].typename = "WirelessInterface"                         
*.SU.wlan[0].radio.typename = "UnitDiskRadio"
*.SU.wlan[0].mac.typename = "CsmaCaMac"


*.ReceptorPU.wlan[0].typename = "AckingWirelessInterface"                       ## Without CSMA
*.ReceptorPU.wlan[0].mac.useAck = false
*.ReceptorPU.wlan[0].mac.fullDuplex = false

*.PU.wlan[0].typename = "AckingWirelessInterface"                       
*.PU.wlan[0].mac.useAck = false
*.PU.wlan[0].mac.fullDuplex = false

*.**.wlan[0].radio.transmitter.communicationRange = 300m
*.**.wlan[0].radio.receiver.ignoreInterference = true
*.**.wlan[0].radio.transmitter.interferenceRange = 600m
*.PU.wlan[0].radio.displayCommunicationRange = true
*.PU.wlan[0].radio.displayInterferenceRange = true
*.SU.wlan[0].radio.displayCommunicationRange = true
*.SU.wlan[0].radio.displayInterferenceRange = true
*.visualizer.mediumVisualizer.displaySignals = true
*.visualizer.physicalLinkVisualizer.displayLinks = true

Here is my .ned file :

package inet.examples.CR;
import inet.networklayer.configurator.ipv4.Ipv4NetworkConfigurator;
import inet.node.inet.INetworkNode;
import inet.physicallayer.contract.packetlevel.IRadioMedium;
import inet.visualizer.contract.IIntegratedVisualizer;


network CR_test
{

parameters:

    @display("bgb=361,394");
    @figure[rcvdPkText_PU](type=indicatorText; pos=350,20; anchor=w; font=,18; textFormat="packets received by PU: %g"; initialValue=0);
    @statistic[packetReceived_PU](source=ReceptorPU.app[0].packetReceived; record=figure(count); targetFigure=rcvdPkText_PU);
    @figure[rcvdPkText_SU](type=indicatorText; pos=350,50; anchor=w; font=,18; textFormat="packets received by SU: %g"; initialValue=0);
    @statistic[packetReceived_SU](source=ReceptorSU.app[0].packetReceived; record=figure(count); targetFigure=rcvdPkText_SU);

    @figure[rcvdPkTextPU](type=indicatorText; pos=350,80; anchor=w; font=,18; textFormat="packets sent by PU: %g"; initialValue=0);
    @statistic[packetReceivedPU](source=PU.app[0].packetSent; record=figure(count); targetFigure=rcvdPkTextPU);
    @figure[rcvdPkTextSU](type=indicatorText; pos=350,110; anchor=w; font=,18; textFormat="packets sent by SU: %g"; initialValue=0);
    @statistic[packetReceivedSU](source=SU.app[0].packetSent; record=figure(count); targetFigure=rcvdPkTextSU);


submodules:
    visualizer: <default("IntegratedCanvasVisualizer")> like IIntegratedVisualizer if hasVisualizer() {
        @display("p=80,35");
    }
    configurator: Ipv4NetworkConfigurator {
        @display("p=170,35");
    }
    radioMedium: <default("UnitDiskRadioMedium")> like IRadioMedium {
        @display("p=260,35");
    }
    PU: <default("WirelessHost")> like INetworkNode {
        @display("p=50,160");
    }
    ReceptorPU: <default("WirelessHost")> like INetworkNode {
        @display("p=300,160");
    }
    ReceptorSU: <default("WirelessHost")> like INetworkNode {
        @display("p=300,280");
    }
    SU: <default("WirelessHost")> like INetworkNode {
        @display("p=50,280");
    }
}

It would be probably a good idea to edit your question and add your network definition and INI files so it would be possible to reproduce this. This can be an issue in INET itself or just some misconfiguration in your INI file. It's hard to tell. — Rudi
I edited my question by including the INI and NED file, thank you :D — H.Inci

Levente Mészáros Levente Mészáros · Accepted Answer · 2018-07-20T11:37:15

This happens when the Packet API is requested to convert a FooChunk to an unrelated BarChunk. The only way to do this is to convert the FooChunk to a binary representation (BytesChunk) and then convert it back to a BarChunk. This process is usually slow and most likely it's a bug in C++ (that's why it's disabled by default). If you don't use any new C++ code in your simulation, only NED and INI files, then the bug is most likely in INET.

Implicit chunk serialization

2 Answers