Automatically Detecting A Vlan - Avaya 9608 Administrator's Manual

Administering Telephone Options
Some switches do not understand a VLAN ID of zero and require frames tagged with a non-zero
VLAN ID.
If you do not want the default VLAN to be used for voice traffic, set the value of L2QVLAN to the
VLAN ID appropriate for your voice LAN.
Another parameter you can administer is VLANTEST. VLANTEST defines the number of
seconds the 9600 IP Series Telephone waits for a DHCPOFFER message when using a
non-zero VLAN ID. The VLANTEST default is "60" seconds. Using VLANTEST ensures that the
deskphone returns to the default VLAN if an invalid VLAN ID is administered or if the phone
moves to a port where the L2QVLAN value is invalid. The default value is long, allowing for the
scenario that a major power interruption is causing the phones to restart. Always allow time for
network routers, the DHCP servers, etc. to be returned to service. If the deskphone restarts for
any reason and the VLANTEST time limit expires, the deskphone assumes the administered
VLAN ID is invalid. The deskphone then initiates operation with a VLAN ID.
Setting VLANTEST to "0" has the special meaning of telling the phone to use a non-zero VLAN
indefinitely to attempt DHCP. In other words, the deskphone does not return to the default
VLAN.
!
Important:
If a VLAN ID is provisioned using DHCP, then L2QVLAN and VLANTEST must
Important:
be provisioned in all DHCP servers that the phone can potentially use.

Automatically detecting a VLAN

The deskphones support automatic detection of the condition where the L2QVLAN setting is
incorrect. When the value of L2QVLAN is not 0 and VLAN tagging is enabled (L2Q= 0 or 1)
initially the 9600 Series SIP IP Telephone transmits DHCP messages with IEEE 802.1Q tagging
and the VLAN ID set to L2QVLAN. The deskphones will continue to do this for VLANTEST
seconds.
If L2Q=1 and the VLANTEST timer expires because a DHCPOFFER has not been
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received, the deskphone sets L2QVLAN=0 and transmits DHCP messages with the
default VLAN (0).
If L2Q=0 and the VLANTEST timer expires because a DHCPOFFER has not been
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received, the deskphone sets L2QVLAN=0 and transmits DHCP messages without
tagging.
If VLANTEST is 0, the timer will never expire.
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114 Deskphone SIP 9608, 9611G, 9621G, 9641G Administrator Guide Release 6.0.1