3Com 5500 switches modifying the built in Quality of Service (QoS)

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I have just installed a new ShoreTel System into a customer which use the 3Com (HP) 5500 switches through out their company. They are very good switches with quite advanced Class of Service (CoS) and Quality of Service (QoS) features. These instructions we provide you with the commands needed to add your manufacture phone to QoS Profile. These instruction should work for the 3com 4500 switch as well as they are the same operating system, but I have not tested this.

The switches do come with an Auto QoS profile which will trust the QoS information provided by the phone. From Shoretel 13 the shoretel  phones are pre-programmed with the correct DSCP values. If you are using this doc to add a different phone, make sure it tags it’s RTP traffic with a DSCP tag of 46 (also known as EF, Expedited forwarding), if not these instructions will do very little to ensure your voice traffic is priorities over other traffic on your LAN.

Out of the box the 5500 wwitch recognises the following phones:

  • Siemens Phones
  • CISCO Phones
  • A5TEK Phones.
  • H3C Phones
  • PINGTEL Phones
  • Verilink Phones
  • 3Com Phones

The switch recognises the phones types but the OUI Mask (the first 3 octets of the mac address)

To enable the switch to trust Shoretel phones and not strip it of it’s QoS tag we need to add ShoreTel on to the list. I decided to replace Pingtel phone as I have never heard of them and it just keeps the list a bit tidier.

The switch will not allow you to remove the Pingtel phone while the QoS profile is active so the first step is to remove the QoS profile from all the ports. This is done with the following command:

Interface GigabitEthernet X/0/X
undo apply qos-profile default                    

*Replace X with each port on the switch (so for a 24 port switch these commands will need to be run 24 times)

Next step is to enter the QOS profile and delete the rule which set the QoS filter for the Pingtel phones by pointing it  to a rule (rule 4) within an access control list (list 4999) for the Pingtel phones. If we do not do this we will not be able to chance the OUI mask as it will still be in use. This is done by the following commands:

qos-profile default
undo traffic-priority inbound link-group 4999 rule 4

Then we need to enter access list 4999 to remove rule 4, then add a new rule in it’s place with the Shortetel Phone’s (or what ever phone you are using) OUI mask. To do this you will need to know the first three octets of the Mac address. For Example Shoretel phones they are 00:10:40 so using the 5500 syntax the OUI Mask will be: 0010-4900-0000 ffff-ff00-0000. For your phones you only need to change the first part in bold, the last 3/4 of the mask will be the same for all phones.

acl number 4999
undo rule 4
rule 4 permit source 0010-4900-0000 ffff-ff00-0000

Then we need to enter the QOS profile again and add the rule which set the QoS filter for Shoretel phones.

qos-profile default
traffic-priority inbound link-group 4999 rule 4 dscp ef cos voice

Now we need to add the QoS profile to all the ports again

interface GigabitEthernet X/0/X
apply qos-profile default

*Replace X with each port on the switch (so for a 24 port switch these commands will need to be run 24 times)

Make sure you save the configuration once your are done.



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  1. I have been asked a question how to confirm this settings are correct in ShoreTel. the instructions are are below:

    To confirm the QOS setting in ShoreTel , log on to ShoreTel Director go to Call Control > Options

    under “Voice Encoding and class of Quality” make sure the “DiffServ / ToS Byte” is set to 184.

    (Also call control quality of service should be 104.)

    DiffServ to DSCP conversion can be found here. http://www.tucny.com/Home/dscp-tos

    These setting are default in later versions of ShoreTel, but always with checking.

    • Barry Akin on November 4, 2015 at 5:35 pm

    Peter, wow, exactly what I was looking for, THANKS!!!

    Question: Wouldn’t I need to apply the QoS to the “Trunking Ports” also? In other words, to be sure that I have everything covered, where you mention “*Replace X with each port on the switch (so for a 24 port switch these commands will need to be run 24 times)”, shouldn’t I also add that to the “trunking ports” 25, 26, 27 and 28?

    1. Hi Barry.

      You are just modifying the default QoS rule, and this rułe is applied to all ports (including the spf ports)

      so these ports (25-28) do need to be included in your new configuration.

        • Barry Akin on November 9, 2015 at 4:06 pm

        Peter, I would like to contract you to look over something for me. Please send me a private email when you are available.


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