August 1999
Intermediate to advanced
328 pages
8h 50m
English
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TYPICAL LAYOUT FOR THE MODEM
Figure 6-5 shows a typical layout for a V Series modem [STEV98]. The architecture is divided into the controller and the data pump. The controller is responsible for compression/decompression operations as well as handling the AT command set.[2] It is also responsible for the V.42 operations, also known as Link Access Procedure for Modems (LAPM). LAPM is a conventional data link protocol. In some situations, Link Access Procedure, Balanced (LAPB) may be used instead of LAPM. They are quite similar to each other and are responsible for the following operations:
[2] The AT (attention) commands are based on the old Hayes modems. The commands are used to "adjust" the operations of the modem and DTE. The commands are used ...