You are installing a Cisco ONS 15454 in a service provider site. A DS3 cable is to be connected to a digital cross-connect system. What is the maximum distance allowed between the two?() 225 ft。 450 ft。 655 ft。 900 ft。
With R4.0, how many total DCC-R tunnel connections can each ONS 15454 support using the TCC+ card? () 10。 32。 64。 84。 96。
滑阀与滑阀座之间、节制阀与滑阀之间可以对研。
What is the difference between 1+1 and 1:1 protection switching?() 1+1 is based on APS, while 1:1 is based on IPS.。 1:1 is used in SNCP switching, while 1+1 is used in MS-SPRing switching.。 1+1 sends signals on Working and Protect paths, while 1:1 sends signals only on Working path.。 1+1 sends signals on Working path ONLY, while 1:1 sends signals on both Working and Protect paths.。
城市公共交通定义、基本任务、地位、特征?
根据JG135-2000《杂物电梯》规定,强制驱动式电梯的顶部间距,在井道顶部,电梯轿厢和井道结构的任何部分之间必须提供一个不小于()mm的距离,使得正常运行时,轿厢不会撞击顶部的缓冲器。