In other cases, however, it is not. If blocks are commonly as small as five or ten bytes, then most of the cross-net data will be control information. The BM option is intended as a simple data compression technique, to remove this overhead from the communication channel. Description of the option The option is enabled through the standard Telnet Option negotiation process. Except for the ability to refuse particular definitions, the receiver of data has no control over the definition and use of mappings.
Data are to be interpreted only as their normal character values.
This avoids the problem of distinguishing between a character which is to be taken as a , and interpreted as its corresponding , and one which is to be taken as its usual Telnet NVT value. In all other cases, however, s are to be interpreted immediately, as if their corresponding s had actually been sent across the network. Expanded strings are not subject to reinterpretation, so that recursive definitions cannot be made. In particular, they may NOT begin outside a macro and continue or terminate inside one, since no macro replacement takes place while processing any Telnet command. The in the subcommand is intended to allow the receiver to allocate storage.