I'm studying for the BCMSN exam. I use the Official Exam Certification Guide from Cisco Press. In the Q&A Chapter 14 (IP Telephony) section I found an answer on a question that I couldn't explain for myself.
Can the CoS information from the voice traffic be passed when the âswitchport voice vlan
untaggedâ command is used? If so, how?
Yes, CoS information is passed within the 802.1p portion of the 802.1Q trunk
My problem with it:
My thoughts are that the voice (and data) traffic will go over the native VLAN with the configuration command shown. And that traffic over the native VLAN is untagged. And without an 802.1Q tag there couldn't be any CoS information in the frames. Where do I go wrong?
Thanks in advance!