The servers are bad lately. They used to get very low std in ping fluctuations and now the graph is always very spikey and I even disconnect in game without it showing any ping spikes on the graph.
Please check your ISP first. When I checked RTT information recorded in Mudfish, it seems RTT stddev values to most of the mudfish nodes are little bit unstable. It means your ISP has a network issue. For details please check http://ko.loxch.com/userrtt/?uid=215852 link.