Avaya 1603SW Betriebsanweisung

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VLAN Considerations
Issue 1 June 2010
85
 
Note:
Note:
Regardless of the setting of L2Q, VLANTEST, or L2QVLAN, you must have 
DHCP administered so that the telephone will get a response to a 
DHCPDISCOVER when it makes that request on the default (0) VLAN. 
After VLANTEST expires, if a 1603SW-I SIP IP Deskphone receives a non-zero 
L2QVLAN value, the telephone will release the IP Address and send 
DHCPDISCOVER on that VLAN. Any other release will require a manual reset 
before the telephone will attempt to use a VLAN on which VLANTEST has 
expired. See the Reset procedure in Chapter 3 of the Avaya one-X™ Deskphone 
Value Edition SIP for 1603SW-I Deskphones Installation and Maintenance Guide
.
The telephone ignores any VLAN ID administered on the Communication 
Manager call server. 
VLAN Default Value and Priority Tagging
The system value L2QVLAN is initially set to “0” and identifies the 802.1Q VLAN Identifier. This 
default value indicates “priority tagging” as defined in IEEE 802.IQ Section 9.3.2.3. Priority 
tagging specifies that your network closet Ethernet switch automatically insert the switch port 
default VLAN without changing the user priority of the frame (cf. IEEE 802.1P and 802.1Q).
The VLAN ID = 0 (zero) is used to associate priority-tagged frames to the port/native VLAN of 
the ingress port of the switch. But 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:
Ensure that the switch configuration lets frames tagged by the 1603SW-I SIP IP 
Deskphone through without overwriting or removing them.
Set the system value L2QVLAN to the VLAN ID appropriate for your voice LAN.
Another system value you can administer is VLANTEST. VLANTEST defines the number of 
seconds the 1603SW-I SIP IP Deskphone 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 telephone assumes the administered 
VLAN ID is invalid. The deskphone then initiates registration with the default 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.