Check the V-lan settings in the ip phone but do this at reboot, from Alex:
7.16 Virtual LAN (VLAN)
The built in Ethernet switch can handle virtual LAN identities and priorities for the LAN port, for the telephone port and for the PC port.
The following possibilities to assign VLAN identities exist:
From DHCP in option 43 (only the phone port, but not the PC port). A list of maximum three VLAN identities can be handled, see Figure 7-37 .
From the configuration file (both the phone- and the PC port).
From a menu where it can be manually set (both the phone- and the PC port).
It is possible to change the different VLAN options from the menu in the boot sequence. The following menu is shown:
Enter the administrator mode, go down in the Network list until the line VLAN for Phone Port occurs.
No VLAN . VLAN shall not be used, but if a VLAN identity is read from the configuration file, VLAN will be used.
Auto. This is the default value when the telephone is delivered from the factory. If the telephone receives a VLAN identity list from DHCP (in option 43) or if there is a VLAN identity defined in the configuration file it will be used. The VLAN identity received from DHCP has priority over the configuration file. For more information, see 7.16.1 Automatic VLAN detection with DHCP and see 7.16.2 Assigning the VLAN identity via the configuration file .
Manually . The manually entered VLAN identity will be used, see 7.16.3 Manual setting of the VLAN identity . But if a VLAN identity is read from the configuration file the manually entered VLAN identity will be overwritten.
Even when VLAN is not used this parameter can have the default value Auto .
Concerning the priority of the frames: For outgoing frames the following priorities will be set at level 2 for each frame by default, when VLAN is used:
For frames originating in the telephone the default value will be 6, meaning voice traffic with less than 10 ms latency.
For frames originating in the PC the default value is 0, meaning best effort.
The priorities can be changed via the configuration file, see description for CONFIGURATION FILE FOR DBC 42X .