Virtual Private Lan Service - Alcatel-Lucent 7750 SR OS Service Manual

IP or MAC filter configured (or none at all) prior to allowing the SAP into the egress multicast
group.
Attempting to change the egress filter configured on the SAP while the SAP is a member of an
egress multicast group is not allowed.
If the configured common egress filter is changed on the egress multicast group, the egress filter
on all member SAPs will be overwritten by the new defined filter. If the SAP is removed from the
group, the previous filter definition is not restored.
SAP Egress QoS Policy
Each SAP placed in the egress multicast group may have a different QoS policy defined. When the
egress forwarding plane performs the replication for each destination in a chain, the internal
forwarding class associated with the packet is used to map the packet to an egress queue on the
SAP.
In the case where subscriber SLA management is enabled on the SAP and the SAP queues are not
available, the queues created by the non-sub-addr-traffic SLA-profile instance are used.
One caveat is that egress Dot1P markings for dot1q SAPs in the replication chain are only
evaluated for the first SAP in the chain. If the first SAP defines an egress Dot1P override for the
packet, all encapsulations in the chain will share the same value. If the first SAP in the chain does
not override the egress Dot1P value, either the existing Dot1P value (relative to ingress) will be
preserved or the value 0 (zero) will be used for all SAPs in the replication chain. The egress QoS
policy Dot1P remark definitions on the other SAPs in the chain are ignored by the system.
Efficient Multicast Egress SAP Chaining
The egress IOM (Input Output Module) automatically creates the SAP chains on each egress
forwarding plane (typically all ports on an MDA are part of a single forwarding plane except in the
case of the 10 Gigabit IOM which has two MDAs on a single forwarding plane). The size of each
chain is based on the dest-chain-limit command defined on the egress multicast group to which the
SAPs in the chain belong.
A set of chains is created by the IOM for each egress flooding list managed by the IOM. While
SAPs from multiple VPLS contexts are allowed into a single egress multicast group, an egress
flooding list is typically based on a subset of these SAPs. For instance, the broadcast/multicast/
unknown flooding list for a VPLS context is limited to the SAPs in that VPLS context. With
IGMP snooping on a single VPLS context, the flooding list is per Layer 2 IGMP (s,g) record and
is basically limited to the destinations where IGMP joins for the multicast stream have been
intercepted. When MVR (Multicast VPLS Registration) is enabled, the (s,g) flooding list may
include SAPs from various VPLS contexts based on MVR configuration.
7750 SR OS Services Guide
Virtual Private LAN Services
Page 343