3Com MSR 50 Series, Руководство по настройке

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498 C
HAPTER
25: V
OICE
VLAN C
ONFIGURATION
n
■
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 (Institute of Electrical
and Electronics Engineers).
■
The default OUI address can be configured/removed manually.
Working Modes of Voice
VLAN
A voice VLAN can operate in two working modes: automatic mode and manual
mode (the mode here refers to the way of adding a port to a voice VLAN).
■
In automatic mode, the system identifies the source MAC address contained in
the protocol packets (untagged packets) sent when the IP phone is powered on
and matches it against the OUI addresses. If a match is found, the system will
automatically add the port into the Voice VLAN and apply ACL rules to ensure
the packet precedence. An aging time can be configured for the voice VLAN.
The system will remove a port from the voice VLAN if no voice packet is
received from it after the aging time. The adding and deleting of ports are
automatically realized by the system.
■
In manual mode, the IP phone access port needs to be added to the voice
VLAN manually. It then identifies the source MAC address contained in the
packet, matches it against the OUI addresses. If a match is found, the system
issues ACL rules and configures the precedence for the packets. In this mode,
the operation of adding ports to the voice VLAN and removing ports from the
voice VLAN are carried out by the administrators.
■
Both modes forward tagged packets according to their tags.
The following table lists the co-relation between the working modes of a voice
VLAN, the voice traffic type of an IP phone, and the interface modes of a VLAN
interface.
Voice VLAN
operating mode
Voice traffic type Interface link type
Automatic mode Tagged voice traffic Access: the traffic type is not supported
Trunk: supported provided that the default
VLAN of the access port exists and is not a
voice VLAN and that the access port belongs
to the voice VLAN
Hybrid: supported provided that the default
VLAN of the access port exists and is not a
voice VLAN. Besides, the default VLAN need to
be in the list of tagged VLANs whose packets
can pass through the access port
Untagged voice traffic Access, Trunk, Hybrid: not supported