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New Member

Access or Trunk port - Voice VLAN ??

Hello ,

We have the following scenary :

2950 switch - - -IP Phones

Is necessary configure the switch port to activate the 802.1q if We only will connect IP phones , not PCs ?

What happen if we configured the switch port like access port , the switch will understand the Cos sent by the IP phone ?

Here the possible config :

interface FastEthernet0/X

switchport trunk encapsulation dot1q

switchport mode trunk

switchport voice vlan (Voice Vlan)

spanning-tree portfast

Sorry but the english isn´t my native language ..

Brgds/Juan Carlos G.


Re: Access or Trunk port - Voice VLAN ??

I would recommend you to leave the port as access and using the switchport voice vlan u will start using VVLAN assignments for the IP phone.

Good link:


New Member

Re: Access or Trunk port - Voice VLAN ??

When you use Cisco Voice VLAN feature, port need not be confiugred as trunk explicitly. Voice vlan information is negotiaed via CDP between switch IP Phone.

Even if you configure switch port as trunk, there is no harm in it. Use trunk native VLAN for data in that case.



Re: Access or Trunk port - Voice VLAN ??

I would read the specific switch manual. The older 3500XL/2950XL required the phone be a dot1q trunk, the newer switches the manual states to only use switchport voice vlan x.