1 引言 回程路径的维护或许是当今有线电视网络中最重要的事,然而很少有人明白。 难怪,直到几年前,有线电视工程师所做的只是把视频不断送往用户,而不管在用户那一端发生什么事。姑且承认,用户端的故障可能会产生网络干扰;但是对于当今的双向网络而言,就像电冰箱交流声这种 1 Introduction The maintenance of backhaul paths may be the most important thing in today’s cable networks, yet few people understand. No wonder that it was only a few years ago that cable television engineers did what they did to keep the video going to the user, regardless of what happened on the user’s side. Admittedly, client-side failures can cause network disruption; but for today’s two-way networks, it’s like a refrigerator hum