automatically assigns the receiving port to a voice VLAN, issues ACL rules and configures the packet precedence. You can configure an aging timer for the voice VLAN. The system will remove the port from the voice VLAN when the aging timer expires if no voice packet is received on the port during the aging timer. The system automatically assigns ports to, or removes ports from, a voice VLAN. Automatic mode is suitable for scenarios where PCs and IP phones connected in series access the network through the device and ports on the device simultaneously transmit both voice traffic and data traffic, as shown in Figure 148. When the voice VLAN works normally, if the system reboots, the system reassigns ports in automatic voice VLAN assignment mode to the voice VLAN after the reboot, ensuring that existing voice connections can work normally. In this case, voice traffic streams do not trigger port assignment to the voice VLAN.

Figure 148 PCs and IP phones connected in series access the network

•Manual mode—You must assign the port to a voice VLAN manually. Then, the system matches the source MAC addresses in the packets against the OUI addresses. If a match is found, the system issues ACL rules and configures the packet precedence. In this mode, you must manually assign ports to, or remove ports from, a voice VLAN. Manual mode is suitable for scenarios where only IP phones access the network through the device, and ports on the device transmit only voice traffic, as shown in Figure 149. In this mode, ports assigned to a voice VLAN transmit voice traffic exclusively, which prevents the impact of data traffic on the transmission of voice traffic.

Figure 149 Only IP phones access the network

Both modes forward tagged packets according to their tags.

Table 46 and Table 47 list the configurations required for ports of different link types to support tagged or untagged voice traffic sent from IP phones when different voice VLAN assignment modes are configured.

•IP phones send tagged voice traffic

157