QosTag Loss when send packet,how to solve?

[hongyu deng]

Hi all,

I have a problem need some guidance, i search and learn from the post to add QosTag to packet.

But it doesn't work! i attach my script and my topology show as below.

I set up onoffapplication in remotehost to send packet to sta, but the qostag loss when invoke SendPacket() {m_socket->Send (packet);} in OnOffApplication.cc(i used Eclipse to debug the code).

If i set up application in ap and sta, ap->sta(data flow), i can use onoffapp -> TraceConnectWithoutContext( "Tx",  MakeBoundCallback (&TagMarker, 6) ); to change qostag.

So my question is why? How can i do to solve this problem?

Any answer is appreciated.

Best,

Hong.

[Tommaso Pecorella]

Hi,

let's not mention that QosTag has been removed from the ns-3 codebase, and this means that you're using an outdated ns-3 release...

There are two possible reasons:

1) QosTag is removed by the NetDevice layers (it was, indeed) before the packet transmission, and

2) You should use a ByteTag anyway, because PacketTags are not resistant to fragmentation and reassembly.

Cheers,

T.

[hongyu deng]

Hi Tommaso,

Thanks for your reply! it is helpful!

Yes, my ns3 version is ns 3.24.1 and the QosTag was removed before packet transmission.

I TRY to use a bytetag but it no work either.

I updata my ns to 3.26 to use SetTos() to set packet's AC. When i test the SetTos() in wifi network, it works ok.

But when i use in the network which i shown before, The SetTos() does not work. The AC_VO app based OnOffApplication packet loss rate is more bigger than the AC_VE app in LTE network .AND in wifi network the PLR are almost same(three stations,tag in AC_VO, AC_VI, AC_BE).

What happen? wether the packet pass in LTE network?

Tommaso sir, could you give some hints about what should i do in next.

Thanks sir,

Hong.

[Tommaso Pecorella]

Hi,

no idea, it could also be a problem of how to evaluate the QoS. remember that LTE is quite robust against performance losses, and often (in any network) the packet drop is due to packets in the same QoS class.

T.

[hongyu deng]

Thanks Tommaso sir.

BR,

Hong.

[Mohamed Ouassim HADJI]

hi, can you share the new code ? plz