User's Manual

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When VIP-1120PT/VIP-2140PT is configured with an VLAN ID, the VLAN ID will be applied on the
outbound packets sent from VIP-1120PT/VIP-2140PT core CPU. This includes all packets, such as ARP,
ICMP, DHCP, DNS, HTTP(S), FTP, SIP, etc.
For packets of which destination is not to VIP-1120PT/VIP-2140PT core CPU, it will be copied to the other
port and will not be added any VLAN ID, nor to remove any. In another words, packets to and from
connected PC will be kept as they are.
While VIP-1120PT/VIP-2140PT tags its outgoing packets with configured VLAN ID, it can accept and
process packets with any VLAN ID or no VLAN ID for both NAP and PAP as long as the destination is to
VIP-1120PT/VIP-2140PT core CPU address.
3.1.2 Configure VLAN for VoIP Priority
QoS is for mobile phone data packets. It is able to distinguish between voice and data application.
It is a common practice in a managed network to configure voice and data application using different
VLANs for prioritization. To separate voice and data traffic by VLAN, the administrator should configure a
VLAN switch with two separated VLANs – One for the voice which goes through a high priority trunk while
the other for data which goes through a normal priority trunk.
The VLAN switch configuration is different from each VLAN switch provider. The administrator should
follow its manual to configure the switch correctly.
For some advanced L2 switch with ALG function, it can identify voice related packets and tagged VLAN ID
automatically which needs no configuration on the phone. For basic L2 switch which supports VLAN
configuration, it must be configured to have certain ports that belong to the voice VLAN and certain ports
that belong to data port and the connected device should have corresponded to tagged VLAN ID,
otherwise, the packets will be discarded.
The folowing pictures show two simple configurations on a VLAN switch to support voice and data priority.