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Hello all,


I have a mix of IP Phone systems and slowly migrating to Cisco every where.  If I have a system where I can change the DSCP marking to 46 can I just configure the switches as though it was all Cisco phones attached?  Trying to avoid having to reconfigure once the site has been migrated to Cisco



I have a mix of switch ports configures as


priority-queue out

mls qos trust DSCP


and others as


mls qos trust device cisco-phone

mls qos trust cos



If I configure all the switch port with mls qos trust device cisco-phone and mark teh pasckets with dscp 46 will they still be prioritized even though the phones are not Cisco?



Thanks in advance.  All replies rated.


Hi Scott,The command "mls qos

Hi Scott,

The command "mls qos trust device cisco-phone" sets up a conditional trust i.e. trusting the markings where this condition is met - that the device is a Cisco Phone. CDP will be looking for and expecting a Cisco phone. If condition is met markings are trusted cos or dscp (depending on second command) if not then markings will be stripped to 0. Since you have non-cisco phones, you will be not be meeting the condition and markings will be stripped.


In your case, as you have non-cisco phones standardize all the switch configs to trust dscp or cos by the command "mls qos tust dscp" (or cos).



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