H3C Technologies H3C S12500 Series Switches - Manual (Page 18)

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Figure 7 Multiple SPB VSIs
Load balancing
To balance traffic between forwarding paths, you can map B-VLANs to different ECT algorithms. When
a path is approaching congestion, you can move part of traffic on one path to another by moving an
I-SID from one ECT algorithm to another.
B-VLAN to ECT algorithm mapping
For balanced traffic distribution, SPBM supports calculating one SPT for a set of B-VLANs by using
different ECT algorithms. IEEE 802.1aq SPB provides 16 ECT algorithms. Each algorithm represents a set
of tie-break rules. As a result, you can have up to 16 forwarding paths in an SPBM network.
Figure 8 shows two SPTs that are calculated by using two ECT algorithms.
Customer site B
Customer site A
Customer site E
Customer site D
Customer site C
VSI 3
VSI 2
BEB
I-SID 400
I-SID 500
BEB
I-SID 300
I-SID 400
BEB
I-SID 400
BEB
I-SID 300
I-SID 400
I-SID 500
BEB
I-SID 300
I-SID 400 VSI 1
SPBM
network