Hello,
When configuring QoS on a 1335 or 1638, we have the following commands:
qos queue-type wrr 25 25 25 expedite
qos dscp-cos 46 to 7
Then on each port we issue the qos trust cos command
interface gigabit-switchport 0/17
qos trust cos
However, on a 1238, we cannot apply the qos trust cos commands to the ports. My question is: Are the following commands sufficient to apply QoS to the entire switch or is there additional configuration needed?
qos queue-type wrr 25 25 25 expedite
qos dscp-cos 46 to 7
Thank you
Hi getzjd:
According to the application note Configuring Ethernet Switch QoS and CoS in AOS (see page 2), the command qos trust cos is not available on NetVanta 123x switches. The document explains that ingress CoS (or DSCP -> CoS) tags will be trusted. If you need to assign a CoS tag for certain ports where ingress frames do not already have a priority, you may use the command qos default-cos <value>.
Best regards,
Chris
So, if I read this correctly, being that our ShoreTel equipment is set for difserv 184 (46 decimal) then packets from the phones should be arriving tagged as 46. Apply the commands below should then be all that I need to issue, correct?
qos queue-type wrr 25 25 25 expedite
qos dscp-cos 46 to 7
The DSCP tags will be preserved (trusted), and so your Layer 2 QoS should function as desired. Your commands look good.
Chris