I need to set up the following on Several Nortel Baystack's (5530/5520):

"Assign a priority to DXL VoIP traffic with a DSCP priority level which will be co-exist with the rest of the real-time traffic on your system. For most cases a priority level of “Expedited” (ef) can be used for VoIP traffic."

If it's easier I can prioritize specific ports.

We are using the java device manager for Nortel devices and have yet to successfully implement QOS. We have found various settings but not a way to apply it to an actual port or type of traffic.

I am familiar with Cisco QOS but not Nortel. I have failed to find appropriate documentation and I can't call support (Nortel doesn't exist anymore). This would be taking place on a security network.

Background information: We have intercoms on a Nortel network that are only working one-way, when they need to be both. On our cisco network the intercoms work both ways without issue (no QOS is configured on Cisco). Our support rep for the intercoms (Harding) suggests that we require QOS on the network. Since my coworkers and myself have hit a wall, we have come here for help.

Thanks in advance.

  • The ERS line is owned by Avaya. There's plenty of documentation, but you really should upgrade the OS -- but beware, Avaya are crap at testing and have created (and recreated) serious bugs; I'm running 6.3.5 in production without issue. (eg. stp failing to block all multicast)
    – Ricky
    Jul 8, 2015 at 21:08

1 Answer 1


[Configuring Quality of Service on Avaya Ethernet Routing Switch 5900 Series]

Ignore that it's for a 5900, the 5500 line was retired a while ago. It's still the same CLI.

show running-config verbose module qos will dump the (almost) entire system configuration for QoS. Take note of the qos if-assign port ... name allQoSPolicyIfcs line as that's how a policy is attached to a port. Defining the other 1000's of things I'll leave to you.

Generally speaking, one-way-voice problems are rarely the fault of QoS. This is almost always a routing (nat, or security) issue where the stream of traffic in one direction is blocked. Inspecting traffic flow should indicate where the breakdown is occurring.

  • Hi Ricky, I will look in to the guide you have provided. I agree that the one-way-voice problem is possibly not a QOS issue, but we have tried everything except what the vendor has recommended. We have a wireshark capture that we can listen to ensuring the data is making it all the way to both sides. The vendor has suggested that the packets arent making it to the intercom in time and are being dropped. We can see the packets at the exchange, and at the master station with full integrity, but I think wireshark is rebuilding it. The intercom is analog so we think that also could be a breakdown.
    – Danny K
    Jul 8, 2015 at 21:51
  • Out of order, maybe. I don't know of any voip gear that cares about transit delay, and in a switched network that's milliseconds at worst.
    – Ricky
    Jul 8, 2015 at 23:30
  • We tested today swapping the Nortel switch with a Cisco one and everything worked just fine as a flat network. Looks like we have been looking in the wrong place for the issue. Thanks for the help!
    – Danny K
    Jul 9, 2015 at 19:01

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