Most of modern IP Phones have a built in switch which allow to integrate endpoints and connect a workstation via the PC port on the IP Phone without the need of an extra port as well as minimize the cabling. Using the built in switch along with VLAN Tagging can integrate the endpoints in the current network while still separating the Voice network from the Data network. A workstation can be connected in the default or different VLAN. In the 3CX Management Console you can apply priority options (and matching switch configuration) to the LAN/WAN port and/or PC port in order to instruct the switch to handle real time traffic, such as RTP (voice) over the normal network traffic.
The Perks of IP Phones built in switch and VLAN Tagging
If you want to add an IP Phone and your workstation is directly connected to a switch port, you don’t need to add an extra port and cabling. In this case, you can add the IP Phone and connect it directly to the switch port using the LAN/WAN port and then the workstation can be connected to the PC port of the IP Phone. Please note that if MAC filter is enabled, the switch must be configured to allow multiple MAC addresses on one this port. If the need arises to split VoIP and PC network from each other additional different VLAN/- priorities can be given to LAN/WAN and/or PC port. This is where the new VLAN provisioning method of 3CX comes into play.
Disadvantages of IP Phones built in switch and VLAN Tagging
Although using the built in switch can eliminate additional hardware/cabling, in an scenario of a workstation connected directly to the PC Port of the IP Phone, upon IP Phone reboot, the workstation is going to lose the IP address. Therefore, it will be isolated from the local network and as a result, any online services/applications will be dropped. And in case of high bandwidth demand (high network traffic) will allocate additional hardware resources from the switch which, in this case, would be the IP Phone, this can lead to audio quality issues if not correctly handled with VLAN priorities and the vendor of the IP phone.
We have prepared a step by step guide to setup IP Phone VLAN provisioning