Configuring VLANs for PC and VOIP Phone

Zyxel_Chris

Symptoms:
UserA reported an issue related to connecting a PC to the LAN network through a VOIP Phone. The setup involves a Zyxel Switch connected to a VOIP Phone, which further connects to a PC. VLANs 20 and 90 are being used, with VLAN 20 designated for PCs and VLAN 90 for VOIP Phones. Despite configuring the current settings with PVID 20 and allowing VLAN 90, the VOIP Phone is not receiving an IP address from VLAN 90, while the connected PC is obtaining its IP address from VLAN 20.

Root Cause:
The problem stems from the VLAN configuration, specifically regarding the assignment of IP addresses to the VOIP Phone and PC, both connected in series.

Solution:
To address this issue, follow these steps:

1. Ensure that the port connecting the VOIP Phone and PC is configured as an "access" port rather than a "trunk" port.

2. Modify the VLAN type to "voice VLAN" on the access port settings.

3. By configuring the port as an access port and specifying the voice VLAN, the VOIP Phone and PC should be able to obtain IP addresses from their respective VLANs, allowing proper communication.