The standardized compression is called v.42Bis, but it was in fact a feature present only on few of USR's models while most of the other brands provided it with

The standardized compression is called v.42Bis, but it was in fact a feature present only on few of USR's models while most of the other brands provided it with consistency. It worked well on plain-text content - I remember hitting 90 KB/sec download speeds when testing large text files on a 28k8 connection - and it made a noticable improvement when bouncing between menus and reading messages and such, but very limited use for actual file transfers since practically everything was already lha/lzh/lzx/dms-compressed.