Configuring the Junos OS to Support Eight Queues on IQ Interfaces for T Series and M320 Routers
By default, IQ PICs on T Series and M320 routers are restricted to a maximum of four egress queues per interface. To configure a maximum of eight egress queues on IQ interfaces, include the max-queues-per-interface statement at the [edit chassis fpc slot-number pic pic-number] hierarchy level:
On a TX Matrix or TX Matrix Plus router, include the max-queues-per-interface statement at the [edit chassis lcc number fpc slot-number pic pic-number] hierarchy level:
 | Note: The configuration at the [edit class-of-service] hierarchy level must also support eight queues per interface. |
The maximum number of queues per IQ PIC can be 4 or 8. If you include the max-queues-per-interface statement, all ports on the IQ PIC use configured mode and all interfaces on the IQ PIC have the same maximum number of queues.
If you include the max-queues-per-interface 4 statement, you can configure all four ports and configure up to four queues per port.
For 4-port OC3c/STM1 Type I and Type II PICs on M320 and T Series routers, when you include the max-queues-per-interface 8 statement, you can configure up to eight queues on ports 0 and 2. After you commit the configuration, the PIC goes offline and comes back online with only ports 0 and 2 operational. No interfaces can be configured on ports 1 and 3.
For Quad T3 and Quad E3 PICs, when you include the max-queues-per-interface 8 statement, you can configure up to eight queues on ports 0 and 2. After you commit the configuration, the PIC goes offline and comes back online with only ports 0 and 2 operational. No interfaces can be configured on ports 1 and 3.
When you include the max-queues-per-interface statement and commit the configuration, all physical interfaces on the IQ PIC are deleted and readded. Also, the PIC is taken offline and then brought back online immediately. You do not need to take the PIC offline and online manually. You should change modes between four queues and eight queues only when there is no active traffic going to the IQ PIC.
