中文在线中文资源,色鲁97精品国产亚洲AV高,亚洲欧美日韩在线一区,国产精品福利午夜在线观看

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.