[cisco-voip] Configuring VoIP on 3750s

[Mike Armstrong]

We just installed a WS-C3750-48P and transferred the port configuration from 
two 3524s to it.  One 7940 refuses to come up, stopping with an "Ethernet 
disconnected" message.  We replaced it with another 7940 and all is well.

While investigating, I actually read the 3750 Software Configuration Guide 
for 12.2(25)SED, and it it says "...voice VLAN is not supported on trunk 
ports."  (p. 15-3.) Their example configuration of a 7960 shows only:

  mls qos trust cos
  switchport voice vlan dot1p

whereas we've been using something like

 switchport trunk encapsulation dot1q
 switchport trunk native vlan 103
 switchport trunk allowed vlan 1,2,103,1002-1005
 switchport mode trunk
 switchport voice vlan 2
 spanning-tree portfast

on the 3524s, and in fact this seems to work on all the other phones we've 
connected to the 3750 so far.  I'm willing to accept that this particular 
phone might need some TAC attention, but my main question at this point is: 
If you can't configue the voice VLAN on a trunk port, how do you set the 
VLAN for the switchport on the phone?  We have no intention of extending 
trust past the phone, and have to set different VLANs for several different 
applications.

Mike Armstrong
UF/IFAS CREC
Lake Alfred, FL