I have 30 workstation and 30 IP Phones all under one single network 192.168.9.0. The network switches is unmanaged switch but supports IEEE 802.1p QoS (e.g.: DLink DGS 1008D
and DGS 1016D
).
I learned that it is better to split the data and voice network to avoid lagging of voice traffic by using VLAN and managed switch.
However, if the network switch support QoS, do I still need to configure VLAN to split the traffic?
Do you trust your workstations to not submit data with a fake QoS header just to get more speed?
You can not avoid that but on a VLAN you can prioritize the VLAN.
Also, on windows doing QoS on the workstations can be tricky ;)
That said, I would say in most cases you do not even need QOS; 30 is a small number of phones and workstations.
I recommend using a separate VLAN whether you use QOS or not. A separate VLAN allows you to set different DHCP options (such as Boot Server) for your phones without affecting your workstations.