Most cellular routers do allow such datacards or USB modems. See voice modem command set for more details on voice modems. Some modems support both VDSL and ADSL. Newer types of broadband modems are also available, including satellite modems and power line modems. Download VOD services are practical in homes equipped with cable modems or DSL connections. Connecting the various sites was an enormous network of telephones, modems and teleprinters. Over 76% of the broadband lines were via DSL and the rest via cable modems. It allowed network sharing of multiple serial devices, such as modems. This also applies to customer-premises equipment, such as cable and DSL modems. Spikes can degrade wiring insulation and destroy electronic devices like battery chargers, modems and TVs. Scrambling is widely used in satellite, radio relay communications and PSTN modems. Two of the company's home telephony modems are the TM402P and the TM502G. They are used both with dial-up modems and ISDN. YMODEM is a file transfer protocol used between microcomputers connected together using modems. Softmodems are cheaper than traditional modems because they have fewer hardware components.