What are the differences between class 1 and class 2 or class 2.0 modems?
During a fax transmission, data is sent in “frames” (or blocks) of data. On a mechanical fax machine, the print head will have physical limitations to how fast a line can be printed. Due to the Modified Hufman encoding of faxes, it is possible to send a single black pixel line in only a few bits. Because the fax machine has to physically move the printer head on the paper, there is a minimum line sending time required while sending data. Fax modems must send the data frames at a speed and timed to accommodate the receiving fax machine. A Class 1 modem only sends frames. The fax software is required to build the frames from the fax data, and then send them with respect to the timing issues for the remote fax machine. In a multitasking environment, the computer may be busy with another task, and miss the timing on one of these frames. When this happens, the fax is aborted. A Class 2 or 2.0 modem handles all the fax framing issues. The software simply gives the modem a command to send the
