I have been reading IEEE 802.1Q 2014 about SPB. I also have watched a few videos about SPB on youtube. However I don't understand why no one mentioned that BPDUs are still transmitted in the network, and IEEE 802.1Q have wrote about SPB in many sections in Spanning Tree.
If IS-IS controls SPB network, why BPDU are still required? I know Agreement Digest is for preventing temporary loop during topology change. But why is it transmitted inside BPDU?