I have a few queries on VOIP prioritization which I'm hoping someone can clarify for me.
We have been using the voice VLAN feature for our IP phones as they have their own ports on the switch (if I understand correctly, Auto-VOIP is for differentiating and enabling prioritization of VOIP traffic when it's sharing a port with other data). I have set the Interface Mode to Dot1p for each member port and set the value to 5. This seems to work mostly okay but not 100%.
So my questions are:
1. What is the difference between what I have done, and going to QoS > CoS > Advanced > CoS Interface Configuration and setting the COS value for the ports there?
2. Is DSCP preferable to COS? I have seen somewhere that COS only works on trunk ports, so does that mean that it won't prioritize traffic within the switch?
2 Our router supports both COS and DSCP, but does it matter once internet-bound traffic has left the switch? Or should the entire link between phones be prioritized, and prioritization information be retained for traffic passing through the router? If so, it sounds like DSCP might be better?