QOS, find port trust mode....

[karl_]

Hello group !

Quick and probably easy question for you, I want validate if a TA are in dscp trusted port mode about qos marking, how can I see this information ?  In fact I need my physical port to trust qos marking for incoming packet, TA should be transparent about qos marking, and not rewrite qos value to default as a untrusted port.

Actually, when I do show run,  on interface config, nothing about qos is present...

Is there, show command I can do  to validate the trust mode for ports ?

Thanks !

[jayh]

The TA900 is a router, not a switch. QoS policies are applied per interface in and out. By default there are no policies applied. You can create a policy matching DSCP entering the interface and marking it leaving, or acting on it by reserving bandwidth, setting in a priority queue, etc.

You won't see the default values in a "show run", but you will in "show run verbose". By default there is no QoS policy set in or out on TA900 interfaces.

When configured, you will see packets matched by policy in the GUI as well as the interface stats. You can also verify with wireshark on the output interface. "show qos map interface eth 0/1" for example will display matched packets.

Full details here: Configuring QoS in AOS

[karl_]

Thank jayh !   Are you able to tell me when port as default, so no qos-policy in and out,  do the port act as transparent wirh dscp marking ?   Example, a port with no qos-policy in and out receiving packet marked with dscp 46...  will this port on TA remark dscp value to default(0) because no qos-policy in are applied ton the port, so untrusting the port.... OR   it will be transparent and do not touch to qos dscp value...?

Thanks again !

[jayh]

There are quite a few parameters that can be matched. DSCP, ToS, VLAN ID, IPv4/v6 ACL, etc. The TA900 isn't intended to be used as a bridge or switch, but as a router and voice endpoint. Usually QoS on these boxes is configured to deal with voice traffic being originated or terminated on the unit itself. I haven't tested it but would suspect that routed traffic with the default QoS map will have DSCP rewritten to 0 leaving. You can test with Wireshark. The guide linked above may have more information.

It gets tricky because the unit is dealing with interfaces at various bandwidths and speeds. QoS on these is more geared to how the box itself prioritizes transit traffic than whether it preserves certain header values. To be on the safe side, I'd configure a match and set on traffic entering and leaving to ensure that DSCP is preserved.