Alcatel-Lucent 7750 SR OS Service Manual page 340

VPLS Features
BPDU Translation
VPLS networks are typically used to interconnect different customer sites using different access
technologies such as Ethernet and bridged-encapsulated ATM PVCs. Typically, different Layer 2
devices can support different types of STP and even if they are from the same vendor. In some
cases it is therefore necessary to provide BPDU translation in order to provide interoperable e2e a
solution.
To address these network designs, BPDU format translation is supported on 7x50 devices. If
enabled on a given SAP or spoke SDP, the system will intercept all BPDUs destined to that
interface and perform required format translation such as STP-to-PVST or vice versa.
Similarly, BPDU interception and redirection to the CPM is performed only at ingress meaning
that as soon as at least 1 port within a given VPLS service has BPDU translation enabled, all
BPDUs received on any of this VPLS ports will be redirected to the CPM.
BPDU translation involves all encapsulation actions that the data path would do for a given
outgoing port (adding VLAN tags, depending on outer SAP, SDP encapsulation type) and adding
or removing all required VLAN information in a BPDU payload.
This feature can be enabled on a SAP only if STP is disabled in the context of the given VPLS
service.
Page 340 7750 SR OS Services Guide