Simple VoIP configuration


I have a client with only 1 vlans - the default vlan and a VoIP called ENAVoice. All the tagging is done at the phone handset.

create qosprofile "QP5"
configure vlan "ENAVoice" qosprofile QP5
configure dot1p type 5 qosprofile QP5
configure dot1p type 6 qosprofile QP5
configure diffserv examination code-point 46 qosprofile QP5

Is there any more that needs to be done to give VoIP priority?

fyi - the creation of ENAVoice tagged 200 and then enabeling of ELRP are the only things this customer has beyond a default configuration.

4 replies

Userlevel 4
Joshua,

My understanding is that you can't use both Dot1P and DiffServ together. In our standard build, we issue a "disable dot1p examination ports all" following the config diffserv line. Here's what our template looks like:

create qosprofile qp5

config diffserv examination code-point 34 qp5

config diffserv examination code-point 46 qp5

enable diffserv examination ports all

disable dot1p examination ports all # if you don't disable dot1p, diffserv won't work

Eric
Thanks. I will try that.
Userlevel 2
Hi Joshua,

Please check the following article

https://gtacknowledge.extremenetworks.com/articles/How_To/Configuring-QOS-profiles-and-verify-QOS-is...

These two points may be of relevance -
  • If traffic is expected to ingress with a DSCP or dot1p value, examination will need to be enabled on the port
  • If the traffic is not expected to ingress with a DSCP or dot1p value already set, ensure examination is disabled and the value is set via VLAN or port
Userlevel 5
If the traffic is already being tagged by the phone and phone is tagged in the VLAN, then the following line is redundant and all you need to do is configure and enable examination:
# configure vlan "ENAVoice" qosprofile QP5[/code]Dot1p values are carried in the 802.1Q header, so the phone port MUST be tagged in the ENAVoice VLAN, if not, then those Dot1p values will be stripped and the above command can be used to re-apply the value to the traffic
DSCP values are carried in the IP Header, so port tagging is inconsequential.

A stream can have both a Dot1p and DSCP value set. On inspection, the Dot1p value will always take precedence.

You can verify your configuration by looking at the following output, if the QP counters are increasing in the correct queue then all is well:

# show ports qosmonitor
Port Qos Monitor
Port QP1 QP2 QP3 QP4 QP5 QP6 QP7 QP8
Pkt Pkt Pkt Pkt Pkt Pkt Pkt Pkt
Xmts Xmts Xmts Xmts Xmts Xmts Xmts Xmts
================================================================================
1 0 0 0 0 0 0 0 0
2 0 0 0 0 0 0 0 0
3 200 0 0 0 0 0 0 0
4 0 0 2398 0 0 0 0 0
5 0 180 0 0 0 0 0 0
6 0 0 0 0 0 0 0 0
7 0 0 0 1533 0 0 0 0
8 0 0 0 0 0 0 0 0
9 0 0 0 0 0 0 0 4
10 0 0 0 0 0 0 0 51504[/code]Kind regards

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