VLAN Stacking, Q in Q, dot1Q tunnel

[houhajou]

Hi,
I'm testing a GPON network (1 OLT and 32 ONUs connected).
For this purpose, I'm generating traffic from a (traffic generator) in both senses; the traffic is tagged with (service) VLANS (835: Net, 838: VoD, 851: ToIP ...).
1-Down Stream direction: the traffic passes through the OLt to the ONUs the goes to the 1/2 to 1/33 ports of an Alcatel OmniSwitch 6850E that sends it to the traffic generator analyse through the port 1/1.
The traffic coming out from the port 1/1 should be tagged with 102, 103, 104 ... to 133 VLANs depending on the receiving port (vlan 102 for port 1/2, vlan 103 for port 1/3 ... vlan 133 for port 1/33), and the service vlan tags shouldn't be modified.

2-Up Stream direction: the traffic (with a dual vlan stack: one of the service vlans encapsulated in one of the 102 to 133 vlan) comes from the generator/analyzer to the port 1/1 of the switch, and should go to the appropriate port (1/2, 1/3 .... 1/33) depending on the first tag (102....133). The egress port should then strip the tag (102 ... 133) and send the frames with only the service tag to the ONU attached.

[askorsasy2k]

Can you Explain this with a Network Diagram for a proper understanding?