QoS on catalys 2950, but with other phone vendors.

[raulalejandroortegameza]

Hi 

I have a problem with a catalys 2950. I need to add QoS, but the phones are not cisco, therefore, the frames are not coming marked with DSCP or COS   to apply politic.

With AutoQoS and cisco phone is easy, but how can I do with other vendor?

Thank...

[raulalejandroortegameza]

I forget mention that PCs are attach to phones with different vlans

[yahsiel2004]

You can force the traffic being recieved on the port to be a certain cos value and then map it to a certain dscp value.

Configuring the CoS Value for an Interface

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Note Both the enhanced and standard software images support this feature.

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QoS assigns the CoS value specified with mls qos cos interface configuration command to untagged frames received on trusted and untrusted ports.

Beginning in privileged EXEC mode, follow these steps to define the default CoS value of a port or to assign the default CoS to all incoming packets on the port:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	interface interface-id	Enter interface configuration mode, and specify the interface to be trusted. Valid interfaces include physical interfaces.
Step 3	mls qos cos {default-cos | override}	Configure the default CoS value for the port. For default-cos, specify a default CoS value to be assigned to a port. If the port is CoS trusted and packets are untagged, the default CoS value becomes the CoS value for the packet. The CoS range is 0 to 7. The default is 0. Use the override keyword to override the previously configured trust state of the incoming packets and to apply the default port CoS value to all incoming packets. By default, CoS override is disabled. Use the override keyword when all incoming packets on certain ports deserve higher priority than packets entering from other ports. Even if a port was previously set to trust DSCP, this command overrides the previously configured trust state, and all the incoming CoS values are assigned the default CoS value configured with this command. If an incoming packet is tagged, the CoS value of the packet is modified with the default CoS of the port at the egress port.
Step 4	end	Return to privileged EXEC mode.
Step 5	show mls qos interface	Verify your entries.
Step 6	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To return to the default setting, use the no mls qos cos {default-cos | override} interface configuration command.

Configuring the CoS-to-DSCP Map

You use the CoS-to-DSCP map to map CoS values in incoming packets to a DSCP value that QoS uses internally to represent the priority of the traffic.

Table 24-3 shows the default CoS-to-DSCP map.

Table 24-3 Default CoS-to-DSCP Map 

CoS value	0	1	2	3	4	5	6	7
DSCP value	0	8	16	24	32	40	48	56

If these values are not appropriate for your network, you need to modify them.

Beginning in privileged EXEC mode, follow these steps to modify the CoS-to-DSCP map:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	mls qos map cos-dscp dscp1...dscp8	Modify the CoS-to-DSCP map. For dscp1...dscp8, enter 8 DSCP values that correspond to CoS values 0 to 7. Separate each DSCP value with a space. The supported DSCP values are 0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48, and 56.
Step 3	end	Return to privileged EXEC mode.
Step 4	show mls qos maps cos-dscp	Verify your entries.
Step 5	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To return to the default map, use the no mls qos map cos-dscp global configuration command.

This example shows how to modify and display the CoS-to-DSCP map:

Switch# configure terminal

Switch(config)#mls qos map cos-dscp 8 8 8 8 24 32 56 56

Switch(config)# end

Switch# show mls qos maps cos-dscp

Cos-dscp map:

        cos:  0  1  2  3  4  5  6  7

     --------------------------------

       dscp:  8  8  8  8 24 32 56 56