The offer is available to both new and existing Verizon customers who switch their mobile plan to the Unlimited Ultimate (starting at $40 per month) or Unlimited Plus (starting at $50 per month) plans. Verizon's three-year price lock guarantee also ensures you'll keep your plan pricing even if costs go up.
简单讲，要做L3，需要先做L2积累数据。那么要做L4，也一样依赖L3的数据。技术上他们是一脉相承的，不存在一口就能吃个胖子的技术路线。
。爱思助手下载最新版本是该领域的重要参考
Highly Divergent Profiles: For routing configurations that are not pre-calculated as common scenarios and whose costs vary too much from default configurations, the original A* algorithm might still be faster (and is often used as an automatic fallback).
Qatar GP — April 12