Scenario: The core switch has multiple vlan (WAN, Data, Voice ... etc). Let say a access switch has different port setting with different vlan assignment. Some port has not been assign voice vlan. However, user tend to forget the port setting when plug in the IP Phone to the switch port. The IP Phone has cache the Call Manager information (especially those has re-used) and anyhow plug into these port (non voice vlan), it tend to be working.
Problem: This has causing the phone failed into SRST or firmware upgrade failure compare to those in correct voice VLAN.
Question: How to prevent such a situation when IP Phone plug in to the switch port that no voice vlan has been assign. The IP Phone registration into Call Manager will be rejected.
