8.1.3 VLAN (Virtual LAN)VLANs are logical segments within a corporate LAN. By assigning VLAN settings to IP telephones, it is possibleto separate the packets transmitted by an IP telephone according to the type of data and specify which VLANeach data type will be sent over. This allows you to avoid generating unnecessary network traffic on eachsegment and to reduce the load on the network. As a consequence, speech quality can be assured. Therefore,we recommend using the VLAN feature to perform VoIP communication effectively.Some IP telephones (e.g., KX-NT300 series) are equipped with 2 ports, primary and secondary, for packetcommunication. Allocating these ports to different VLANs enables you to split the paths for packets dependingon whether the packet contains voice signals or data.VLAN settings (VLAN ID and VLAN priority) for the primary port affect voice data transmitted by the IPtelephone, whereas VLAN settings for the secondary port apply to data transmitted by a PC connected to theIP telephone. When sending packets, the IP telephone can attach information on which VLAN the packets areto be transmitted over (VLAN Tagging). The switching hub that receives these packets reads the VLANinformation and sends the packets over the appropriate VLAN. This helps to ensure bandwidth for IP telephonevoice transmissions.In this way, an IP telephone with 2 ports can transmit voice packets from the primary port with higher prioritythan other packets from the secondary port.NoticeThe PBX’s LAN port does not support VLAN tagging. Therefore, connect the PBX’s LAN port to a port ofthe switching hub that is set to "Untagged", and the IP telephone to a port set to "Trunk", to allow VLANtagging. Consult your network administrator for details.PBXIP Telephone with 2 portsVLAN 1VLAN 1VLAN 1VLAN 2VLAN 2VLAN 1Segment for Voice DataVLAN 2Segment for Other DataVoice PacketOther PacketPCPCOther PacketVLAN 2VLAN-capable Switching HubPrimary SecondaryUntagged312 Installation Manual Document Version 2016-038.1.3 VLAN (Virtual LAN)
