Voice VLAN

[saquib.tandel]

Hi

What is the difference between these options, and which one is recommended over the other.

Considering single cable connecting from Switch to phone to PC

### Edge switch - config

#1

int fa 0/1

switchport trunk encap dot 1q

switchport mode trunk

switchport trunk allowed vlan 2,12

#2

int fa 0/1

switchport mode access

switchport access vlan 2

switchport voice vlan 12

==============================

#### Core

int vlan 1

description Server VLAN

ip add 192.168.1.1 255.255.255.0

int vlan 2

description User VLAN

ip address 10.1.1.1 255.255.254.0

ip helper-address 192.168.1.100

int vlan 12

description voice vlan

ip addres 10.100.100.1 255.255.254.0

----------------------------------------------------------------

DHCP / DNS configured on Windows 2008 - 192.168.1.100

Voice Server - 192.168.1.55

Thanks

ST

[cadet alain]

Hi,

in #1: both VLANs are tagged and in #2 only the voice VLAN is tagged.

Regards.

Alain.

[saquib.tandel]

Thanks

What is the best practise approach for voice traffic based on you EXPERT experience.  Also seeking your opinion on QOS approach for LAN and WAN Users on voice traffic .

[cadet alain · Accepted solution]

Hi,

I'm far from being an expert but Cisco recommends the 2nd approach when possible or you could trunk if your switch doesn't regcognize auxiliary VLANs and put the data VLAN as the native VLAN.

As far as QoS goes here is what Cisco recommends: http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book.html

Regards.

Alain.