Networking
OptiX OSN 3500 TM - SD
4-8
Corp A
Corp B
Corp A
Corp B
PE1
PE2
P
P
Port A
Port B
Port A
Port B
Tunnel Label
VC Label
Data
Company
60
10
...
Corp A
70
20
...
Corp B
...
...
...
...
60
10
Data
70
20
Data
65
10
Data
75
20
Data
10
Data
20
Data
Tunnel label
switching
Tunnel label
switching
Tunnel label
stripped
Frame transfered by
PE2 according VC label
L2 MPLS Network
composed by OptiX
OSN 3500
Figure 4-9
Application of EPL/EVPL service
8. EPLAN/ EVPLAN Service
The OptiX OSN 3500 adopts the Martini mode to provide the EPLAN/ EVPLAN and
implement the multipoint-to-multipoint connection of user sites. From the angle of user,
the EPLAN/ EVPLAN network is a big Vlan where the user service can be converged.
As shown in Figure 4-10, when the user’s Ethernet frame (with the source address
being MAC H, and the destination address being MAC A, B or C) enters the PE
equipment, the system will check the Layer 2 transfer table and attach the internal
label (VC Label) it gets to the frame. Then, the frame is transferred to corresponding
tunnel, where it is attached with the external label (Tunnel Label), and different Label
Switch Paths (LSPs) are set up according to different addresses. The Ethernet frame
is detached from the Tunnel Label when leaving the P equipment, and then
transferred to corresponding PE equipment, where the VC Label is detached. After
that, the Ethernet frame is transferred to corresponding output port according to the
Layer 2 transfer table.