Hackers and phreakers usually have areas of expertise. In Australian terms, Anthrax was a master of the X.25 network and a king of voice mailbox systems, and others in the underground recognised him as such. He knew Trilogues better than most company technicians. He knew Meridian VMB systems better than almost anyone in Australia. In the phreaking community, he was also a world-class expert in Aspen VMB systems. He did not, however, have any expertise in DMS 100s. Anthrax quickly hunted through his hacking disks for a text file on DMS 100s he had copied from an underground BBS. The pressure was on. He didn't want to spend long inside the exchange, maybe only fifteen or twenty minutes tops. The longer he stayed without much of a clue about how the thing operated, the greater the risk of his being traced. When he found the disk with the text file, he began sorting through it while still on-line at the telephone exchange. The phreakers' file showed him some basic commands, things which let him gently prod the exchange for basic information without disturbing the system too much. He didn't want to do much more for fear of inadvertently mutilating the system. Although he was not an authority on DMS 100s, Anthrax had an old hacker friend overseas who was a real genius on NorTel equipment. He gave the list to his friend. Yes, the friend confirmed it was indeed a DMS 100 exchange at a US military base. It was not part of the normal telephone system, though. This exchange was part of a military phone system. In times of war, the military doesn't want to be dependent on the civilian telephone system. Even in times of peace, voice communications between military staff are more secure if they don't talk on an exchange used by civilians. For this and a variety of other reasons, the military have separate telephone networks, just as they have separate networks for their data communications. These networks operate like a normal network and in some cases can communicate to the outside world by connecting through their own exchanges to civilian ones. When Anthrax got the word from the expert hacker, he made up his mind quickly. Up went the sniffer. System X was getting more interesting by the hour and he didn't want to miss a precious minute in the information gathering game when it came to this system. The sniffer, a well-used program rumoured to be written by a Sydney-based Unix hacker called Rockstar, sat on System X under an innocuous name, silently tracking everyone who logged in and out of the system. It recorded the first 128 characters of every telnet connection that went across the ethernet network cable to which System X was attached. Those 128 bytes included the username and the passwords people used to log in. Sniffers were effective, but they needed time. Usually, they grew like an embryo in a healthy womb, slowly but steadily. Anthrax resolved to return to System X in twelve hours to check on the baby.