I'm late, I know. But if someone is interested why this setup can't work, here my theory:
CPU has sent out the initial UAUDP packet with vlan tag 2 to establish an IP NOE connection between 7775(oxo) and 5001(phone). This packet gets through the VPN tunnel to the phone as untagged IP packet. The phone answers and in the payload of the UAUDP protocol it tells in which vlan itself is. You can see this in packet no. 48 in the tcpdump trace:
Code: Select all
Universal Alcatel/UDP Encapsulation Protocol, Connect-Message:
Opcode: connect
...
Keepalive: 9
QoS IP TOS: 0
QoS 802.1 VLID: 0
QoS 802.1 PRI: 255
just a theory.