VLANs

Aperto®'s VLAN implementation has the following features:

• The SU has the ability to VLAN tag incoming packets, on the basis of Port, Source or Destination IP addresses or subnets and Source or Destination MAC addresses
• The SU can transparently pass through already tagged VLAN packets
• The SU can classify packets on the basis of their VLAN tag, and assign them to their own Virtual SU.
• The SU can Double Tag already tagged packets, and thus create a VLAN tunnel. This facility can be used by operators to carry their subscribers VLAN traffic over the operator's own metropolitan VLAN network, without changing the VLAN tag on the subscriber's packet.
• The SU can over-write the VLAN tag of incoming packets which have pre-existing VLAN tags. The 802.1p priority bits can also be over written in this manner by the SU.
• Management traffic, such as DHCP and TFTP, can be assigned their own separate VLAN tags. This feature allows the DHCP and TFTP servers to differentiate between SUs on the basis of their VLAN tags. For example in a carrier of carriers operator model, one can have SUs from several ISPs mixed in the network, each of them is assigned a different management VLAN ID, which allows their DHCP requests to be sent to the ISPs own DHCP server.