Vlan Tagging; Vlan Detection - Avaya one-X 1603SW Administrator's Manual

Administering Telephone Options

VLAN Tagging

IEEE 802.1Q tagging (VLAN) is a useful method of managing VoIP traffic in your LAN. Avaya
recommends that you establish a voice LAN, set L2QVLAN to that VLAN, and provide voice
traffic with priority over other traffic. If LLDP was used to set the telephones' VLAN, that setting
has absolute authority. Otherwise, you can set VLAN tagging manually, by DHCP, or in the
46xxsettings.txt file.
If VLAN tagging is enabled (L2Q=0 or 1), the 1603SW-I SIP IP Deskphones set the VLAN ID to
L2QVLAN, and VLAN priority for packets from the telephone to L2QAUD for audio packets and
L2QSIG for signalling packets. The default value (6) for these parameters is the recommended
value for voice traffic in IEEE 802.1D.
Regardless of the tagging setting, a 1603SW-I SIP IP Deskphone will always transmit packets
from the deskphone at absolute priority over packets from secondary Ethernet. The priority
settings are useful only if the downstream equipment is administered to give the voice LAN
priority.
!
Important:
VLAN tags are always removed from frames that egress (go out of) the
Important:
secondary Ethernet interface.

VLAN Detection

The Avaya IP Telephones support automatic detection of the condition where the L2QVLAN
setting is incorrect. When VLAN tagging is enabled (L2Q= 0 or 1) initially the 1603SW-I SIP IP
Deskphone transmits DHCP messages with IEEE 802.1Q tagging and the VLAN set to
L2QVLAN. The telephones will continue to do this for VLANTEST seconds.
If the VLANTEST timer expires and L2Q=1, the telephone sets L2QVLAN=0 and transmits
●
DHCP messages with the default VLAN (0).
If the VLANTEST timer expires and L2Q=0, the telephone sets L2QVLAN=0 and transmits
●
DHCP messages without tagging.
If VLANTEST is 0, the timer will never expire.
●
84 Avaya 1603SW-I SIP Deskphones Administrator Guide