Alcatel-Lucent 7750 SR OS Service Manual page 342

VPLS Features
Required Common SAP Parameters
Only SAPs created on Ethernet ports are allowed into an egress multicast group.
Required common parameters include:
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SAP Port Encapsulation Type
The access port encapsulation type defines how the system will delineate SAPs from each other on
the access port. SAPs placed in the egress multicast group must be of the same type. The supported
access port encapsulation types are null and dot1q. While all SAPs within the egress multicast
group share the same encapsulation type, they are allowed to have different encapsulation values
defined. The chained replication process will make the appropriate dot1q value substitution per
destination SAP.
The normal behavior of the system is to disallow changing the port encapsulation type once one or
more SAPs have been created on the SAP. This being the case, no special effort is required to
ensure that a SAP will be changed from null to dot1q or dot1q to null while the SAP is a member
of a egress multicast group. Deleting the SAP will automatically remove the SAP from the group.
SAP Port Dot1Q EtherType
The access port dot1q-etype parameter defines which EtherType will be expected in ingress dot1q
encapsulated frames and the EtherType that will be used to encapsulate egress dot1q frames on the
port. SAPs placed in the same egress multicast group must use the same EtherType when dot1q is
enabled as the SAPs encapsulation type.
The normal behavior of the system is to allow dynamic changing of the access port dot1q-etype
value while SAPs are currently using the port. Once a dot1q SAP on an access port is allowed into
an egress multicast group, the port on which the SAP is created will not accept a change of the
configured dot1q-etype value. When the port encapsulation type is set to null, the ports dot1q-
etype parameter may be changed at any time.
SAP Egress Filter
Due to the chaining nature of egress efficient multicast replication, only the IP or MAC filter
defined for the first SAP on each chain is used to evaluate the packet. To ensure consistent
behavior for all SAPs in the egress multicast group, when an IP or MAC filter is configured on one
SAP it must be configured on all. To prevent inconsistencies, each SAP must have the same egress
Page 342
SAP Port Encapsulation Type on page 342
SAP Port Dot1Q EtherType on page 342
SAP Egress Filter on page 342
7750 SR OS Services Guide