1 Reply Latest reply on Mar 4, 2018 10:58 AM by jayh

    Voice Configuration qos-map check and recommendation for a voice only deployment

    jamesd New Member

      I was looking for a recommendation on max-reserved-bandwidth & qos-map

       

      I am looking for the maximize a voice only on 900e 3rd gen. Is there a recommend max-reserved-bandwidth? Up to 90%??

       

      THIS WAS DONE WITH THE MAX-RESERVED-BANDWIDTH at default, 75%

      The balance of kbps works out exactly.

       

      qos map VOICE 10

      match dscp 46

      match dscp cs3

      match dscp 41

      priority percent 70

      exit

      !

      qos map VOICE 20

      match dscp cs2

      bandwidth percent 5

      exit

      !

      interface ppp 1

        qos-policy out VOICE

       

      AT PPP 1 INT MAX MAX-RESERVED-BANDWIDTH 85%

       

      qos map VOICE 10

        match dscp 46

        match dscp cs3

        match dscp 41

        priority percent 80

      qos map VOICE 20

        match dscp cs2

        bandwidth percent 5

       

        interface ppp 1

        description ppp 1

        ip address  xxxxxxxxxxxxxxxxxx

        media-gateway ip primary

        peer default ip address xxxxxxxxxxxxx

        max-reserved-bandwidth 85

        qos-policy out VOICE

        no shutdown

        cross-connect 1 t1 0/1 1 ppp 1

        • Re: Voice Configuration qos-map check and recommendation for a voice only deployment
          jayh Hall_of_Fame

          It's at 75% because that's a good compromise. You can go higher but if everything is voice and you're doing no data at all do you really need QoS? The idea of limiting it is to allow routing protocols, administrative access, etc. in the event of severe congestion. If you're using 75% of the pipe for priority traffic, you probably need a bigger pipe or will very soon.

           

          Yes, you can go to 90%. Keep the RTP in a low-latency priority queue. SIP needs little bandwidth and can take buffering and latency but avoid drops with reserved bandwidth. I've run SIP at 2% on busy networks. Make sure your DSCP values are being set as intended and reset to 0 any DSCP from untrusted networks.