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#226 Branch 1.3.1.0: Handle QoS value correctly

1.4.2.0
closed
None
2019-06-12
2018-12-18
No

Fix for QoS handling (according to IEC) based on release 1.3.1.0

Discussion

  • Bernd Löhr

    Bernd Löhr - 2019-01-21
    • Milestone: 1.4.1.0 --> 1.4.2.0
     
  • Bernd Löhr

    Bernd Löhr - 2019-01-29

    Can you please describe in more detail, what you want to do? There is a request about DSCP regarding 1.4.1 as well. We should consolidate these requests.

     
  • Matthias Mossner

    If we interprete IEC 61375-3-4: Ethernet Consist Network (ECN) 4.6.3 Assignment of priority level: "The binary representation of DSCP field shall be as follows LLL000" correctly the value from XML has just to be shifted by 5. Therefore we implemented it the following way:

    sockOptValue = (int) (pOptions->qos << 5);

    Therefore the "user" can decide what the DSCP has to look like, this is at least the most flexible way.

     
  • Matthias Mossner

    However my colleague Holger Waldmann recognized that there is a gap between the interpretation of DSCP IEC has and how it is widely used in other internet applications :-(

     
  • Bernd Löhr

    Bernd Löhr - 2019-01-30

    This is because of changes in the meaning and the reinterpretation of the TOS field. The support and handling as DSCP field depends on the router vendor and is optional for TCN-ETB. In IEC61375-2-5 C. 11 ETB Quality of Service the DSCP and VLAN QoS are mangled and in 61375-3-4 C. 4.9.5.1 Consist Switch it says that a layer 2 consist switch needs to check for the IP (layer 3) DSCP field...

     
  • Bernd Löhr

    Bernd Löhr - 2019-06-12
    • status: open --> closed
     
  • Bernd Löhr

    Bernd Löhr - 2019-06-12

    Closed as the QoS handling has been changed by setting the DSCP and the QoS (VLAN priority), at least in the POSIX implementation.

     

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