PBB Features
Page 586 7210 SAS-X, R6 OS Services
node) shares the available backplane bandwidth with the traffic received on the front-
panel ports numbered #12-22. The user must account for this additional amount of BUM
traffic while configuring services on the front panel ports to ensure that the internal
backplane is not congested. SAP Ingress meters can be used to limit the amount of traffic.
NOTE: If only PBB Epipe is used (no I-VPLS service is configured for use), then egress
port mirroring can be enabled without affecting PBB traffic, since PBB Epipe traffic does
not use the two-pass approach.
• The system uses the internal loopback to flood/replicate BUM traffic received on the B-
SAP, to create an additional copy for processing in the I-VPLS context. The system also
uses the internal loopback to for egress port mirroring. The user needs to ensure that
aggregate amount of mirrored traffic in the system and the BUM traffic received on a B-
SAP does not exceed the available internal loopback bandwidth. Ingress meters can be
used to limit the amount of BUM received and processed from a B-SAP and user can limit
the number of ports setup for port egress mirroring to control the maximum amount of
traffic that needs to be circulated for two pass processing using the internal loopback.
NOTE: If only PBB Epipe is used (no I-VPLS service is configured for use), then egress
port mirroring can be enabled without affecting PBB traffic, since PBB Epipe traffic does
not use the two-pass approach.
• In 7210 SAS-X, the flooding mechanism used for BUM traffic results in two copies being
sent to the traffic manager, one the B-VPLS copy and second the I-VPLS copy. This can
potentially congest the inter-connect, connecting the traffic manager to the packet
processor chip. In release 4.0R1, the congestion must be avoided by using ingress meters
to ensure that total forwarded traffic (for all traffic types) does not exceed the available
bandwidth.
• Multiple B-SAPs on the same port cannot be part of the same B-VPLS service. Two B-
SAPs on the same port need to be configured in two different services.
• Processing rules for packets received with multiple B-tags on a SAP:
→ If the B-Tag header has two tags, the packet is processed and forwarded appropriately
and sent out of an I-SID service or another B-VPLS B-SAP.
→ If the node is acting as a pure BCB (with no ISID/service termination), then the
packets are flooded and switched appropriately and if the node is acting as a BCB +
BEB, then the packets are flooded and switched appropriately on the B-SAPs, but they
will not switched or flooded to a I-SAPs (both VPLS and Epipe I-SAPs).
• PBB I-tag etype is not configurable, it is set to 0x88e7.
• PBB B-tag etype is not configurable; it is set to 0x8100.
• PBB packets received from a destination MAC address other than the one configured in
the epipe service is not accepted by 7210 devices.
• In the current release, PBB packets with UCA bit set are dropped.
• Aging of MAC addresses learnt in the B-domain - As long as a Customer MAC (C-MAC)
or an Epipe service is associated with an B-SA/B-MAC, do not age out the B-SA. When
the last customer MAC ages out or the last epipe service using the particular B-SA MAC
To Next Page
Loading...
