What: Hierarchical virtual private LAN service (H-VPLS)
Why you should care: H-VPLS allows for virtual private LAN customers on pseudo-wires to be divided and then aggregated onto the same edge network, which can reduce the number of label distribution protocol sessions required of the network core. H-VPLS as a concept is already a few years old, but only now is becoming a factor as carriers seek to further grow their Ethernet service availability. As carriers continue to expand their VPLS offerings, as AT&T recently did, we will probably begin to see more H-VPLS announcements as well.