cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements
Join Customer Connection to register!
535
Views
0
Helpful
0
Replies
Juan Urti
Beginner

QoS LAN Design - mls qos trust cos/dscp

Hi all! I´m Juan from Argentina. 

I´m studying for my CCIE WR exam,  and i have 3 questions.


Topology

PC - IP Phone - SW L2 - Trunk to another L3 SW (here there are all the interface vlans) - SW L3 trunk to Router - Router connected to WAN MPLS.

In the connection between IP Phone and L2 SW, i have configured "mls qos trust cos", to trust in the CoS field of ip phone.

My questions are:

1- In the trunk between L2 and L3 switch. What kind of  configuration  must i use? Must I trust in DSCP or CoS field? What command type I must use? Trust dscp or cos., or both.

2- In the trunk between L3 and Router. What kind of  configuration  must i use?? What command type I must use? Trust dscp or cos, or both

3- When a L3 Switch send a frame (after dscp-cos table), does the switch utilize CoS field in the egress frame?

Sorry by my english

Best Regards

Juan

0 REPLIES 0