[2021] A carrier grade L2BSA gateway with netgraph - Lutz Donnerhacke

In Germany, broadband access is still based on copper to the house due to historical, political reasons. In order to increase transfer rates vectoring became ubiquitous. That’s why all wires between houses and a curb need to be operated by a single company. Unfortunately, Germany does not distinguish between layer2 operators and layer3 operators. So either all households have to buy Internet from a monopolist or a layer2 transmission to a third party ISP must be regulated. The regulated access to the layer2 bitstream of a customer is defined by the regulation authority and implemented as a so- called A10NSP gateway. In principle at this point all layer2 traffic is encapsulated by an additional VLAN tag for each customer line. The VLAN tag itself is defined to be fixed as long as the DSL is in sync, but will change randomly on resync. Existing A10NSP solutions are expensive, closed appliances which provide only a single type of access: PPPoE. We offer triple play via DHCP on multiple VL