Given a telnet data buffer, Telnet will normalize the buffer with
respect to telnet commands and option negotiation, eliminating telnet
command sequences per RFC 854.  It will also determine when a
telnet connection is encrypted, per the use of the telnet encryption
option per RFC 2946.

==== Configuring the inspector to block exploits and attacks

ayt_attack_thresh number

Detect and alert on consecutive are you there [AYT] commands beyond the
threshold number specified.  This addresses a few specific vulnerabilities
relating to bsd-based implementations of telnet.
