CoS Switchport Queue Default Assignement
Here are the default CoS assignement for the queue unless you modify the standard
- CoS value 0,1 => Queue 1
- CoS value 2,3 => Queue 2
- CoS value 4,5 => Queue 3
- CoS value 6,7 => Queue 4
QoS over VPN Tunnel
To avoid to lose , all the QoS settings when your traffic is encapsulated into a VPN Tunnel , you can use the command qos pre-classify which will copy automatically bits for a packet’s ToS Byte into ToS byte from the tunnel header. With this you can preserve your QoS settings end-to-end even if you are crossing a VPN Tunnel.
NBAR
NBAR stands for Network Based Application Recognition and can look beyond L3 and L4 information , all the way up to L7 .
Don’t forget also that NBAR relies on CEF enabled.
MQC supported markings
Here are also all supported markings after you have classified your traffic :
- IP Precendence (set ip precedence <<value>>)
- DSCP (set ip dscp <<value>>)
- QoS group (set ip precedence <<value>>)
- MPLS experimental bits (set mpls experimental <<value>>)
- Frame Relay DE bit (set fr-de)
- ATM CLP bit (set atm-clp)
Tools to classify traffic under a class-map
Here are all tools that we can use to classify the traffic under a class-map:
- ACL
- Existing markings ( CoS,IP Precedence,DSCP)
- QoS group
- Protocol (using NBAR)
- Traffic matching another class-map
- Mac-address (source or destination)
- Range of UDP ports