欧美日韩亚州综合,国产一区二区三区影视,欧美三级三级三级爽爽爽,久久中文字幕av一区二区不卡

VDSL (very-high-speed digital subscriber line) technology is similar to the well-known ADSL, and facilitates the delivery of information at speeds of up to 52 Mb/s. Standard VDSL deployment uses a frequency spectrum up to 12 MHz, whereas VDSL2 allows for up to 30 MHz as an option.