Voice Vlan Assignment Modes - 3Com 4510G Configuration Manual

In general, as the first 24 bits of a MAC address (in binary format), an OUI address is a globally
unique identifier assigned to a vendor by IEEE. OUI addresses mentioned in this document,
however, are different from those in common sense. OUI addresses in this document are used by
the system to determine whether a received packet is a voice packet. They are the results of the
AND operation of the two arguments mac-address and oui-mask in the voice vlan mac-address
command.
You can remove the default OUI address of a device manually and then add new ones manually.

Voice VLAN Assignment Modes

A port can be assigned to a voice VLAN in one of the following two modes:
In automatic mode, the system matches the source MAC addresses in the untagged packets sent
when the IP phone is powered on against the OUI addresses. If a match is found, the system
automatically assigns the port to the voice VLAN, issues ACL rules and configures the packet
precedence. You can configure voice VLAN aging time on the device. The system will remove a
port from the voice VLAN if no packet is received from the port after the aging time expires.
Assigning/removing ports to/from a voice VLAN are automatically performed by the system.
In manual mode, you should assign an IP phone connecting 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,
assigning/removing ports to/from a voice VLAN are performed manually.
Both modes forward tagged packets according to their tags.
The following table lists the co-relation between the port voice VLAN mode, the voice traffic type of an
IP phone, and the port link type.
Table 8-2 Co-relation
Voice VLAN assignment
mode
Automatic mode
Voice traffic
type
Access: not supported
Trunk: supported if the default VLAN of the
connecting port exists and is not the voice VLAN and
Tagged voice the connecting port belongs to the default VLAN
traffic
Hybrid: supported if the default VLAN of the
connecting port exists and is not the voice VLAN and
the traffic of the default VLAN is permitted to pass
through the connecting port
Untagged
Access, Trunk, hybrid: not supported
voice traffic
8-2
Port link type