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New Member

QOS for VOIP traffic on Nexus 7000


Just after some advice please regarding QOS on Nexus 7000. Our Nexus 7000's form a collapsed distribution/core layer, our access layer switches are are a mixture of Cisco 3750 & Cisco 4507. 3750 switches will connect to Nexus switches via 1Gb uplink, 4507 switches will connect via 10Gb uplinks.

Each Nexus will be connected via 20Gb port channel, all servers connect to the Nexus switches via 1Gb links.

We're implementing a new telephone system soon which will be using VOIP so I need to configure the switches to perform QOS. The IP phones will mark the RTP traffic with DSCP value EF and call signaling traffic CS3. I'm fine configuring qos on the access layer switches, its just the Nexus switches which I'm not sure about.

Do I actually need to configure any QOS parameters on the Nexus switches so they will prioritise the VOIP traffic. If my understanding  the Nexus switches will trust the DSCP values and assign the traffic to the relevent queues?

Just for information VOIP is the only traffic I will be marking QOS values

Many Thanks

  • LAN Switching and Routing
New Member

QOS for VOIP traffic on Nexus 7000


Please, please could someone help me with this.

Many Thanks


New Member

QOS for VOIP traffic on Nexus 7000


Just seent eh following on the Nexus qos guide.

"These are either priority or normal queues. If you use the priority keyword in your configuration, these are used as priority queues. Otherwise, they are used as normal queues."

So I presume I will have to configure configure priority queues?


QOS for VOIP traffic on Nexus 7000

NX-OS and the 7K runs standard MQC QoS architecture. Classification can be done on:

ACL Classification

DSCP Classification

IP Precedence Classification

Protocol Classification

QoS Group Classification

Discard Class Classification

Layer 3 Packet Length Classification

CoS Classification

IP RTP Classification

Class Map Classification

NX-OS also supports marking, policing and queuing and scheduling.

There are two types of class maps, policy maps, and service polices are:

Type queuing: Queuing objects define interface queuing policies (which is what i think you are referring to)

Type qos: QoS objects define forwarding engine policies:

If no type specified, type qos is assumed

Type Queueing class maps are pre-defined based on the physical hardware possibilities (different line cards, different capabilities). The assignment of these pre-defined class maps may be attached to policy maps within each non-default VDC. In order to create customized Type Queueing class maps, the configuration must be completed within the default VDC context.

Note: Type Queueing class maps may only have Class of Service (CoS) assigned to the policy maps.

Class-map configuration for type queuing are as follows:

class-map type queuing match-any (class-queuing-name): Creates or accesses the class map

match parameter: Which parameter the packet needs to match against



Posted by WebUser Adriaan Steyn

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