Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 263)

Multi-Service IronWare Switching Configuration Guide 233
53-1003036-02
Chapter
9
IEEE 802.1ad - Provider Bridges for the Brocade NetIron
CES and Brocade NetIron CER
About IEEE 802.1ad
In a Provider Bridge (PB) network, a provider VLAN is called a Service VLAN (SVLAN), and a
customer VLAN is called a Customer VLAN (CVLAN). A CVLAN carries a default tag-type of 0x8100.
The range of customer VLANs (CVLANs) can be mapped to an SVLAN, allowing a CVLAN to cross a
provider boundary. The SVLAN can be configured to provide service, tunnels, or broadcast
domains. The SVLAN and the CVLAN are sent in the same packet so that customer packets with
VLAN information are carried to the customer network on the other side.
A Provider Edge (PE) device receives packets with no tags, or packets with CVLAN information, and
adds an SVLAN field on the packet before sending to the provider network. The device can be
configured to perform SVLAN translation at an inter-provider boundary.
Figure 22 provides an
example of a PB network.
FIGURE 22 IEEE 802.1ad network
The CVLAN carries a default tag-type of 0x8100. SVLAN encapsulation is similar to CVLAN but with
a different tag type (default 0x88a8). A customer's 4K CVLAN domain can be mapped to an SVLAN,
allowing the customer VLAN domain to cross a provider boundary. The SVLAN can be configured to
provide services, tunnels or broadcast domains.
At an inter-provider boundary, if necessary, the SVLAN value inserted by the first provider may be
replaced by a different SVLAN value (this is referred to as SVLAN translation).
IEEE 802.1ad Provider Bridging limitations
The following provider bridging limitations apply to PB networks:
• An SVLAN can have a value between 1- 4090
• An SVLAN limit of 4K VLANs is typically inadequate in the carrier space.