I need some quick advise regarding LAN QoS. I have been asked to implement QoS on our network to prioritise voice traffic that will be transiting our VPLS WAN. I have already configured policies to classify and mark voice traffic as required and ensure that these markings are maintained to our egde routers where the provider has then configured the required polices to prioritise voice traffic. So far this is all good.
I have been asked if I should be also configuring queuing on our LAN switches, specifically on the interfaces facing our VoIP equipment and WAN routers. From what I can see, the interfaces that connect to our voip equipment only carry voice traffic so I cant see a need for queuing as we are not contending with other traffic? Also the interfaces that connect to our WAN routers show no signs of congestion so do we really need queuing here as well?
I'm not trying to avoid the implementation of queuing on our switches but if its not needed then is really required or recommended?
Happy to hear your thoughts?
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Probably dont need it by the sounds of it , if switches aren't under any congestion , does the voice sound ok now without any qos from lan to lan phone and test video calls are not laggy or choppy ?
what type of lan switches are they
did you wireshark the packets make sure the EF ,markings are being held while transmitting the LAN network , if they are your probably good
Thanks for the response.
Voice/video calls between devices on the LAN are fine and it was only issues with inter-site calls that we were having issues with but WAN QoS has since fixed this.
Sorry the access switches are Cisco 2960Xs and the core are 6500s
Markings are being maintained end-to-end so thats all good from what I can see
Thank you for the response, that makes sense
Actually stating that there is no congestion is incorrect, what I meant to state was that I cant see any output drops on the interfaces which is different. Maybe I need to implement some monitoring to check if the output queues are being filled at all to confirm this
No drops is a good sign, but with VoIP, delay and jitter can be issue even when there's no drops.
I personally define congestion whenever any frame/packet needs to be enqueued. However, QoS is only really needed when congestion and/or drops is actually adverse to the service needs of the traffic. Again, even if there's no adverse issues today, QoS provides insurance for tomorrow.