1-3
tag to communicate with the voice gateway. In this case, the port connecting to the IP phone must
be configured to allow the packets tagged with the voice VLAN tag to pass.
z
An untagged packet carries no VLAN tag.
z
A tagged packet carries the tag of a VLAN.
To set an IP address and a voice VLAN for an IP phone manually, just make sure that the voice VLAN ID
to be set is consistent with that of the switch and the NCP is reachable to the IP address to be set.
How Switch S4210 Identify Voice Traffic
Switch S4210 determine whether a received packet is a voice packet by checking its source MAC
address against an organizationally unique identifier (OUI) list. If a match is found, the packet is
considered as a voice packet. Ports receiving packets of this type will be added to the voice VLAN
automatically for transmitting voice data.
You can configure OUI addresses for voice packets or specify to use the default OUI addresses.
An OUI address is a globally unique identifier assigned to a vendor by IEEE. You can determine which
vendor a device belongs to according to the OUI address which forms the first 24 bits of a MAC address.
Switch S4210 support OUI address mask configuration. You can adjust the matching depth of MAC
address by setting different OUI address masks.
The following table lists the five default OUI addresses on Switch S4210.
Table 1-1
Default OUI addresses pre-defined on the switch
Number
OUI address
Vendor
1 0003-6b00-0000 Cisco
phones
2
000f-e200-0000
3Com Aolynk phones
3 00d0-1e00-0000 Pingtel
phones
4 00e0-7500-0000 Polycom
phones
5 00e0-bb00-0000 3Com
phones
Setting the Voice Traffic Transmission Priority
In order to improve transmission quality of voice traffic, the switch by default re-marks the priority of the
traffic in the voice VLAN as follows:
z
Set the CoS (802.1p) priority to 6.