On the other hand, on the link which connects IP Phone to switch, passes both tagged voice and untagged data traffic. Only, untagged data is passed over this link. As you can see, in this topology, IP Phone is connected to the switch and then PC is connected to that IP Phone. Here, a basic topology like below is used. Here, you need a solution.įor such a topology, to overcome this issue, multiple ports on the IP Phone are used beside a specific Voice VLANs configuration on the switch By using a separate Voice VLAN beside the Data VLAN, you can use both of these devices over a single link. What if you are using multiple devices and one of them is an IP Phone? You have one cable but you need to access two different services. The data connection is done over this cable. Generally, only one network cable comes to the desk in the office.