Letters (incomplete) Dear 2600: Is it true that Blue Boxing is on the way out? I hear it has something to do with CCIS. What exactly is this and why is it so troublesome to phreaks? Worried Phreak Dear Worried: Blue Boxes are indeed a dwindling resource. But there's no need to throw them out yet. They aren't going to be totally useless for quite some time. Basically, AT&T is converting to CCIS trunks. These don't allow boxing. In-band signaling is the only kind of trunk sugnaling that supports boxing. It is by far the most prevalent at the moment. Basically, in-band uses a 2600 hertz tone to indicate that a trunk is idle, and thus can accept routing instructions from an "outsider". To box a call, the criminal blasts 2600 down the line after making a long distance call. The line thinks it's idle and waits for routing instructions. Now the criminal puts a KP tone and a ST tone around the number that he's trying to get through to. These comprise the routing instructions. Thus, the line thinks it's idle, then it receives the routing instructions, and routes the call to whereever the person sent it. Now, his central office (CO) which does all the billing still thinks he is making the call to wherever, so it keeps billing him at that rate. If it happens to think he was making a toll-free call, it won't bill him at all! Another form of signaling is out of band. This uses control tones out of the normal band of telephoone transmission (approximately 800 hertz to 3000 hertz). The idle tone is 3200, others shifted upward as well. So why couldn't you make a new box? Don't forget, it's out of band. These tones aren't in normal transmission, so the local CO and customer interface loop just don't bother to transmit them. You can blast all the 3200 you want - it won't go through the CO to the trunk. But this is not the "death of boxing" as it has several disadvantages to the telco too numerous to mention. The real death of boxing lies in Common Channel Interoffice Signaling (CCIS). This is a direct connect data line going from one ESS switcher to another at speeds up to 4.8 kB (usually 1.2) - incredible speeds. All routing instructions are sent through these lines. It isn't looking for control tones on the trunk; it's getting them elsewhere. This means that you can blast 2600 hertz tones all you like. It won't make a difference because the equipment is no longer listening for them. This kind of signaling is being phased in all over the country. Look for one in your neighborhood. Since CCIS has benefits for really high volume trunks, you can try looking for long distance trunks to Canada, or rural states. These probably won't be phased in for a long time, if at all. (Remember, very few companies just invest in new technology for new tech's sake; even AT&T won't be able to do this for long). 2600 Magazine, Volume 2, Number 11, November 1985