FTT/x is the general name of all kinds of optical fiber communication networks, among which X represents the destination of optical fiber lines. According to the distance between optical fiber and users, it can be divided into four service forms: Fiber to the Cabinet; FTTCab; Fiber to the Curb; FTTC; Fiber to the Building; FTTB; and Fiber to the Home; FTTH. This is the case. Verizon, an American operator, refers to FTTB and FTTH as Fiber To The Premise (FTTP), which can be collectively referred to as FTT/x.