10.2 Queuing Options
10.2.8 Configuring custom queuing
Step 1—Set Queue Priority

You can configure CQ to filter for an interface or a protocol. For example, you can do the following:

  • Send all traffic from Ethernet interface 0 to custom queue 1.
  • Send all IP traffic to custom queue 2.
  • Send all IPX traffic to custom queue 3.
  • Send all AppleTalk traffic to custom queue 4.

You can create an output CQ list by using the protocol or the interface as discriminating criteria.
Use the
queue-list protocol command to specify inclusion of a protocol in a particular queue. To create an output CQ list with the queue-list protocol command, use the following syntax :

Router(config)#queue-list list-number protocol protocol-name queue-number queue-keyword keyword-value

You can also create an output CQ list with the queue-list interface command. Use the queue-list interface command to establish queuing priorities on incoming interfaces :

Router(config)#queue-list list-number interface
interface-type interface-number queue-number


In Cisco IOS Release 11.0, the maximum number of queues that can be used for CQ increased from 10 to 16. Sixteen queues are assigned by default.

Step 2—Assign a Default Custom Queue

Assign a default custom queue. You can assign a queue for those packets that do not match the custom queue filtering. 
Use the
queue-list default command to assign packets to a queue if no other queue list conditions are met :

Router(config)#queue-list list-number default queue-number

If no default queue is specified, default traffic is queued to queue 1.

Step 3—Use the optional queue-list queue limit Command

Change the queue capacity. You can designate the maximum number of packets that a queue can contain. To limit the length of a particular queue, use the optional queue-list queue limit command :

Router(config)# queue-list list-number queue queue-number limit limit-number

Step 4—Configure the Service Threshold per Queue

Configure the service threshold per queue. To allocate more bandwidth to the traffic of a protocol or traffic from an interface, you increase the size of a queue.

Use the queue-list queue byte-count command to set the minimum byte count transferred from a given queue at a time. This value is specified on a per-queue basis :

Router(config)#queue-list list-number queue queue-number byte-count byte-count-number

If a queue threshold (the maximum byte count) is reached during the transmission of a packet, the whole packet is still allowed to go through because the router will not split a packet for the purpose of queuing.

For example, the default threshold of 1500 bytes is used on a given queue. The first packet assigned to that queue is 1100 bytes, and the second packet is 300 bytes. The threshold has not been reached yet because the byte count is currently at 1400 bytes. The next packet assigned to the same queue is therefore processed, regardless of its size. If the third packet is 1000 bytes, the whole packet is processed, for a total byte count of 2400 bytes. The fourth packet will be put on hold while the router services the subsequent queues.

Step 5—Assign the Custom Queue List to an Interface

Assign the custom queue list to an interface. The filters of the queue list are applied to all traffic that passes through the interface.

Use the
custom-queue-list command to link a queue list to an interface :

Router(config-if)#custom-queue-list list
Lab Activity    
  Our company has given us the task of connecting our Houston office with the Orlando office via Frame Relay.