Composition of 7.ADSL and network hardware

ADSL is called asymmetric digital subscriber line. ADSL technology divides data transmission into asymmetric uplink and downlink rates. ADSL provides uplink rates of 1M and downlink rates of up to 8M within a range of 5 kilometers. The ratio of up to down is 1:8.

ADSL advantages: high-speed transmission, Internet calls do not interfere, shared bandwidth, convenient installation, affordable price.

ADSL Standards:

ITU-T G.992.1(G.dmt) uplink: 1.5M downlink: 8M

ITU-T G.992.2(G.lite) uplink: 512K downlink: 1.5M

ITU G.992.5(ADSL2+) uplink: 3.5M downlink: 24M

ITU G.992.5(Annex M) Uplink: 3.5M Downlink: 24M

ADSL login method:

PPPOA: ATM (Asynchronous Transfer Mode) based dial-up access, providing a username and password.

PPPOE: Provide a username and password, access via dial-up connection.

v Direct Connect: Provide dedicated public network static IP for Direct Connect.

Home routers have two Ethernet ports: WAN port: WAN port, LAN port: local area network port.

TP-LINK dial PPPOE access diagram:

Routing switch hardware components:

v CPU: Central processing unit, arithmetic processing data.

v RAM: Equivalent to computer memory, used for temporary cache exchange data.

v ROM: equivalent to the computer BIOS, used to boot the system.

v Flash: Flash memory, equivalent to the computer's hard disk, used for storage systems.

NVRAM: Configuration register, device that permanently stores configuration.

Router boot process: power-on self-test, boot system in ROM flash, load configuration in NVRAM.

Note: When Flash cannot find the system, it will automatically load into the ROM system.