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QoS VoIP Issue still

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  • 1.  QoS VoIP Issue still

     
    Posted 04-03-2018 02:12

    Hi,

     

    Many apologies for disturbing you experts with this issue again, but I am having real problems even getting the basic working:

     

    So, I have the following as a test:

     

    BGP Router --> Core1 --> LNS1

     

    I am simply running an extended ping from the BGP Cisco Router to the LNS interface address. I am classifying at the Core1 Interface facing the BGP Router. Here is my configuration:

     

    set interfaces ge-1/0/1 unit 0 family inet filter input mf-classifier
    set interfaces ge-1/0/1 unit 0 family inet address 192.168.100.2/30
    set interfaces ge-1/0/1 unit 0 family iso

    set class-of-service classifiers dscp v4-ba-classifier forwarding-class voice loss-priority low code-points 101110
    set class-of-service forwarding-classes queue 0 BE-data
    set class-of-service forwarding-classes queue 1 Premium-data
    set class-of-service forwarding-classes queue 2 voice
    set class-of-service forwarding-classes queue 3 NC
    set class-of-service interfaces ge-1/0/1 unit 0 classifiers dscp v4-ba-classifier
    set firewall family inet filter mf-classifier term priority from source-address 192.168.100.1/32
    set firewall family inet filter mf-classifier term priority then count voice
    set firewall family inet filter mf-classifier term priority then forwarding-class voice
    set firewall family inet filter mf-classifier term priority then accept
    set firewall family inet filter mf-classifier term all-else then accept

     

    Now, I clear the interface stats and send an Extended ping test with the following settings:

     

    Target IP address: 172.16.16.33
    Repeat count [5]: 500
    Datagram size [100]:
    Timeout in seconds [2]:
    Extended commands [n]: y
    Source address or interface: 
    Type of service [0]: 184 --->dscp is ef
    Set DF bit in IP header? [no]:
    Validate reply data? [no]:
    Data pattern [0xABCD]:
    Loose, Strict, Record, Timestamp, Verbose[none]:
    Sweep range of sizes [n]:
    Type escape sequence to abort.

     

    And the results from the "show interface ge-1/0/1 extensive" command show the following:

    Queue counters:               Queued packets                    Transmitted packets                      Dropped packets
    0                                             503                                              503                                                  0
    1                                               0                                                   0                                                    0
    2                                               0                                                   0                                                    0
    3                                              13                                                 13                                                   0
    Queue number: Mapped forwarding classes
    0 BE-data
    1 Premium-data
    2 voice
    3 NC

     

    I expected to see the packets go into the Voice queue (number 2) and not into the Best Effort queue. Does not matter what I do I cannot get this marked traffic into the right queue

     

    Any help please



  • 2.  RE: QoS VoIP Issue still

     
    Posted 04-03-2018 03:16

    Is it possible that the following is occuring:

     

    Juniper sees the Voice traffic as "46" DSCP - 101110 because it only reads the leading 6 bits...... However, when an extended ping is completed from a Cisco device it sends all 8 bits, hence the 2 extra zero's on the end and therefore changing the marking requirement to 184. I have tried 46 and 184 and neither makes any difference. But as mentioned, that could be because of a ping compatibility issue with the way Cisco sends and what Juniper is expecting to receive.

     

    If I needed to check what was happening here, what is the best way to achieve this please?



  • 3.  RE: QoS VoIP Issue still

     
    Posted 04-04-2018 01:17

    Okay, so I made a couple of changes as I realised that the firewall filter for the Classifier appears to be for unmarked traffic that can be marked upon Egress.... so, I just left in the DSCP command and pointed it to the voice queue. Again, no difference. So I tried with a VoIP phone sending SIP traffic unmarked and used a firewall filter and classifier. I got really weird results with this....

     

    1: It made no difference to the traffic. It still ended up in the Best Effort Queue.

    2: When the Classifier was applied to the ingress interface, I lost the eBGP peering..... When I removed the classifier the BGP peering became "Established" again. ---- That's weird.

     

    So, does anyone have any idea why the eBGP peering relationship would be affected by the classifier?



  • 4.  RE: QoS VoIP Issue still

     
    Posted 04-04-2018 03:31

    Ignore the Classifier part. I have now got that working.

     

    I still have the issue where the traffic is being sent to the BE-Data queue (Best Effort) and not the voice queue.... I am looking at a different program that will allow me to ping test on certain ports....

     

     



  • 5.  RE: QoS VoIP Issue still
    Best Answer

     
    Posted 04-04-2018 07:47

    Okay, I now have it working. The data is going to the correct queue.

     

    Just for peoples information... Cisco do indeed add the 2 bits to the CoS type of service... so, normally SIP VoIP would look like the following:

     

    32   16   8   4   2    1

    1     0      1   1   1    0     =   46

     

    So, normally we would look for dscp 46 in ToS field, but because of the added 2 zero's we get the following:

     

    128    64    32    16    8    4    2    1

    1        0       1       1     1    0    0    0    =    184

     

    So, when running the extended ping, make sure in the ToS field you type 184 if you are expecting dscp 101110.

     

    Anyway, hope that helps someone