H3C Technologies H3C WX5500E Series Access Controllers - Manual (Page 159)

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it automatically assigns the receiving port to the voice VLAN, issues ACL rules and configures the
packet precedence. You can configure a voice VLAN aging time on the device. The system will
remove a port from the voice VLAN if no packets are received from the port during the aging time.
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 transmit both voice traffic and data traffic at the same time, as
shown in
Figure 44 . 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 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 44 PCs and IP phones connected in series access the network
• Manual mode—You must manually assign an IP phone accessing port to a voice VLAN. Then, the
system matches the source MAC addresses carried in packets against the device's OUI addresses.
If the system finds a match, it 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 45 . In this mode, ports assigned to a voice VLAN
transmit voice traffic exclusively, which prevents data traffic from impacting the transmission of voice
traffic.
Figure 45 Only IP phones access the network
Both modes forward tagged packets sent out of IP phones according to their tags. Table 15 and Table 16
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.
If the port that receives tagged voice traffic from an IP phone is configured with 802.1X authentication
and any of the guest VLAN, Auth-Fail VLAN, and critical VLAN features, assign different VLAN IDs to the
voice VLAN, PVID of the accessing port, and 802.1X guest, Auth-Fail, or critical VLAN.
When IP phones send untagged voice traffic, the voice traffic receiving ports must operate in manual
voice VLAN assignment mode. To implement the voice VLAN feature, you must also configure the PVID
of each receiving port as the voice VLAN. As a result, you cannot implement 802.1X authentication.