we need support for QOS DSCP pass through on cisco switch any suggestions

[chee.tsai]

support for QOS DSCP pass through on cisco switch any suggestions

[Collin Clark]

It's supported

[chee.tsai]

I am looking at ME 3800 and 3750 and I dont see any commands to co

nfigure DSCP passthrough like waht it use to have on 3560.

Do you know which Model supports DSCP passthrough higher then 3750?

[Edison Ortiz]

If you don't enable MLS QoS, DSCP values will be preserved as they transit via the switch.

If you enable MLS QoS, you need to enable trust dscp/cos on the ports facing devices on which you want the DSCP value to be preserved.

[chee.tsai]

So on 3800 there is no MLS...support

So DSCp will be preserved?

[Edison Ortiz]

3800 is a router so no MLS is required. Your question pertained to switches.

Routers will not modify the DSCP information by default unless you re-classify traffic with MQC (Modular QoS CLI).

[chee.tsai]

ortiz

I am refering to ME 3800 switch router. on 4500 also there is no MLS so both will be DSCP passthroug?

[Edison Ortiz]

We don't have a Metro-E 3800 model. We have a Metro-E 3750 model.

It does support mls qos while the 4500 is mls qos but the command is simply QoS.

If you don't enable mls qos, or qos on the 4500, dscp will be transparent.

[chee.tsai]

Ortiz

i am refering to

http://www.cisco.com/en/US/products/ps10965/index.html

I have just bought one, and thinking of buying two more, if they support DSCP pasthough, this to make sure that I pass dscp value taken from my customer on incomming ethernet port and handed over to mpls cloud on outgoing ethernet port unchanged as this is crucial requirement.

[Edison Ortiz]

Ah, 3800X not 3800 as you mentioned.

According to the documentation

http://www.cisco.com/en/US/docs/switches/metro/me3600x_3800x/software/release/12.2_52_ey/configuration/guide/swqos.html

it uses the same QoS concept as a router. DSCP can only be modified with MQC and if you do nothing, DSCP transparency is supported by default.

[chee.tsai]

Thanks

I dont intend to do any thing so it will passthrough and now I can be 100% sure......

[Edison Ortiz]

Yup, you should be fine. I wish you best of luck and please post here if you run into issue.

Don't forget to rate helpful posts.

Regards,

Edison