Servers are not 86% of the total. All power consumption must be cooled. The paper says networking is 7.1% of non-cooling (5/70). That must also be cooled and using the ratio 30/70 cooling power/non-cooling power gives ~ 3/7.1 ratio for the networking cooling. Therefore networking is taking about 8% (5 + 3) of the power in a datacenter according to your source. Is this not significant? Remember that future demands mean networking needs to be done at higher speeds which would mean a greater percentage of the total power usage.

rogue