need help getting started w/ QoS

Discussion in 'Cisco' started by bruce, Dec 15, 2004.

  1. bruce

    bruce Guest

    We're just starting to test IP phones at a couple of our remote
    offices. Our phone equipment is all Nortel. Our LAN switches are all
    Cisco.

    My initial searches on Cisco VLANs and QoS have turned up a seemingly
    endless amount of reading on this. I'm hoping someone w/ experience can
    narrow down my options.

    I've created a couple of port-based VLANs on a 2950 - one for pc data,
    one for voice data, and trunk those to a PIX 506. What is the best
    method to ensure that traffic from the voice data VLAN has a higher
    priority on the trunk port of the 2950, and on the PIX?
     
    bruce, Dec 15, 2004
    #1
    1. Advertising

  2. bruce

    Ben Guest

    bruce wrote:
    > We're just starting to test IP phones at a couple of our remote
    > offices. Our phone equipment is all Nortel. Our LAN switches are all
    > Cisco.
    >
    > My initial searches on Cisco VLANs and QoS have turned up a seemingly
    > endless amount of reading on this. I'm hoping someone w/ experience can
    > narrow down my options.
    >
    > I've created a couple of port-based VLANs on a 2950 - one for pc data,
    > one for voice data, and trunk those to a PIX 506. What is the best
    > method to ensure that traffic from the voice data VLAN has a higher
    > priority on the trunk port of the 2950, and on the PIX?
    >


    Basically you need configure a priority queue on the trunk link.

    This assumes that your voice traffic is already marked to a higher CoS
    (layer 2)/DSCP (layer 3) than your data traffic as it comes into the
    switch. I am not familiar with Nortel phones but Cisco IP phones do this
    by default. All phone ports should be set to TRUST incoming markings.
    All data ports should be set to NOT trust incoming markings and remark
    to a default Cos/DSCP.

    The end result is your voice traffic will get real-time service and
    always get served before data packets if they are waiting in line.

    On the pix side it shouldn't be necessary to do anything for traffic
    inbound from the switch.

    Outbound from the pix it depends a lot on the rest of your network. In
    general if you have a qos-enabled network you should be marking
    everything to default qos at the edge, except where you can be sure
    existing markings can be trusted. Assuming your network is delivering
    traffic with reliable markings to the pix, then a similar setup on the
    PIX is needed.

    I have no idea of the pix qos features, but, if it's similar to IOS, you
    again need to use the modular qos interface (MQC) to create a policy-map
    with a priority queue.
     
    Ben, Dec 16, 2004
    #2
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Bill McCarty

    Getting Started

    Bill McCarty, Aug 12, 2005, in forum: Firefox
    Replies:
    4
    Views:
    544
    Old Gringo
    Aug 12, 2005
  2. Andrew Albert

    QOS for VOIP using 768k of FR / Auto QOS

    Andrew Albert, Feb 6, 2005, in forum: Cisco
    Replies:
    7
    Views:
    1,517
  3. Mike

    Getting Started

    Mike, Dec 30, 2005, in forum: Cisco
    Replies:
    1
    Views:
    412
    Arnold Nipper
    Dec 30, 2005
  4. dominix
    Replies:
    2
    Views:
    484
    dominix
    Feb 6, 2007
  5. Jason
    Replies:
    3
    Views:
    450
    Jason
    Jul 17, 2007
Loading...

Share This Page