Internet fax machines. This has limited the standard's use, though a system for looking up a fax's email address based on its phone number is under development. To work with existing fax machines, all iFax machines support standard faxing (requiring a regular phone line). Alternatively, an iFax can be used in conjunction with a fax gateway. Internet fax Internet fax, e-fax, or online fax is the use of the internet and internet protocols to send a fax (facsimile), rather than using a standard telephone connection and a fax machine. A distinguishing feature of Internet fax, compared to other Internet communications such as
Fax transmitted. This is effective as most lines differ little from their predecessor. This is not continued to the end of the fax transmission, but only for a limited number of lines until the process is reset and a new 'first line' encoded with MH is produced. This limited number of lines is to prevent errors propagating throughout the whole fax, as the standard does not provide for error-correction. This is an optional facility, and some fax machines do not use MR in order to minimise the amount of computation required by the machine. The limited number of lines is two