Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 286)

256 Multi-Service IronWare Switching Configuration Guide
53-1003036-02
Integrated IEEE 802.1ad and IEEE 802.1ah
10
• Layer 2 switches in the IEEE 802.1ah-encapsulated network are normal Provider Bridging
systems, which process BVLAN header as if it was an SVLAN-encapsulated packet.
• Tag-types - BVLAN and SVLAN tag-types are the same (default 0x88a8), so the Provider
Bridging system inside the PBB network can process BVLAN packets as they were SVLAN
encapsulated.
• ISID Operation:
• 24-bit ISID supports the provider bridging operation framework where an Ethernet Virtual
Circuits (EVC) setup gives the closed environment for customer packets on the two ends to
be limited to the EVC.
• Customer MAC address learning is limited to the ISID domains that are part of an EVC. A
PBB device does not need to learn customer MAC addresses that are not part of this EVC.
This provides scalability, as devices are not required to store every customer MAC address
that passes through the provider backbone network.
• BVLAN: BVLAN provides the network connectivity among PBB nodes.
NOTE
While in a Provider Bridging network the SVLAN provides both the networking operation and
service interconnection, in a PBB network the service provisioning (ISID) is totally independent
on networking framework (BVLAN).
Figure 33 provides an example of a Provider Backbone Bridged (PBB) network interconnecting two
Provider Bridged (PB) networks.
FIGURE 33 Provider Backbone Bridged network interconnecting two Provider Bridged networks
802.1ad 802.1ad 802.1ah
PB
PB
PB PB
PBB PBB
CVLAN
SVLAN CVLAN
CVLAN
CVLAN CVLAN SVLAN
SVLAN ISID BVLAN B-SA B-DA
CPE
CPE