Specifications

Watson 5 Ethernet
Operating Manual
W5-Ethernet-Manual.doc
Version 2.0-01
3-12 Revision: 2006-04-27
3.2.4 VLAN Examples
VLANs are always used within the Watson 5 Ethernet plugin to segregate traffic from different ports.
This is true even when no VLAN tags are present on packets ingressing or egressing the plugin.
Figure 3-6 below shows a simple VLAN configuration example. Both on the DSL and on the
Ethernet side untagged packets are used. On the Watson 5 Ethernet plugin four VLANs (VLAN 1,
VLAN 2, VLAN 3 and VLAN 4) are configured. Depending on its ingress port each packet gets a de-
fault tag between 1 and 4. This tag is then used to switch the packet to the correct egress port, ef-
fectively connecting ETH1 to DSL1, ETH2 to DSL2 etc. while blocking all traffic between Ethernet
ports and between DSL ports. The VLAN configuration of Figure 3-6 is automatically activated when
issuing the DEFAULT 2 monitor command.
ETH1
ETH2
ETH3
ETH4
DSL1
DSL2
DSL3
DSL4
1 1
2 2
3 3
4 4
1
2
3
4
1
2
3
4
VLAN 1
VLAN 2
VLAN 3
VLAN 4
Untagged Untagged
1
1
Default VLAN Tag
VLAN Port Membership
Figure 3-6: Simple VLAN Example
Figure 3-7 shows how the VLAN switching function can be used for traffic concentration:
ETH1
(ETH2)
(ETH3)
(ETH4)
DSL1
DSL2
DSL3
DSL4
1, 2, 3, 4
1
2
3
4
1
2
3
4
VLAN 1
V
L
A
N
2
V
L
A
N
3
V
LA
N
4
Tagged
Untagged
1
1
Default VLAN Tag
VLAN Port Membership
Figure 3-7: VLAN configuration for traffic concentration
In this example four independent DSL customers are concentrated to a single Ethernet trunk inter-
face. On the DSL lines untagged packets are used. Upon ingress into the Watson 5 Ethernet plugin
the packets get a default VLAN tag between 1 and 4 based on their ingress port. All traffic is
switched to port ETH1 which is member of all four VLANs. The packets egress the Watson 5
Ethernet plugin with VLAN tags, allowing to separate traffic streams from the four DSL ports differ-
ent customers. Ports ETH2 .. ETH4 are unused in this scenario.