101-0725#

[ThoughtPhreaker 174]

So last night I started talking to someone about the ex-McLeodUSA network. It's Windstream now, but it's still separate from all the other networks they bought. Basically, they function as a CLEC, and have a bunch of DMS-500s scattered around the country accordingly. These being DMS-500s, they function basically the same as DMS-100 end offices, but with the added benefit of routing long distance traffic like a DMS-250. There's one nearish to where I live, so I decided I'd try dialing a carrier access code for McLeod.

 

Sure enough, I dlal 101-0725# and dialtone! Or something like it anyway. Now if you're like me and don't subscriber to their CAC, what you get is a little locked down. Probably for the better - casual dialing is a real pain in the ass. So what can you dial on here?

 

That's something I'm still figuring out. First I tried the most obvious thing I could think of; 800-711-3408. For those of you who don't know, that's the number for a feed of a TV station in Dallas. Some time ago, they ported the toll-free number over to McLeod. Sure enough, it works! Then for the hell of it, I tried 800-MCL-EOD1. And I got an ad.

 

At first, I thought that might've just been one of their old numbers, and the switch was doing an actual SMS-800 dip for the call; if you do a resporg lookup, the ad is handled by a company called BH Telecom. But then I tried calling another ad belonging to that same company in an unrelated prefix, and I was greeted with a perky sounding "Great news!". And for the first time calling those, it actually was great news! I think I figured out what's going on. BH Telecom, whoever they are, is using McLeodUSA facilities for their traffic, and the switch will terminate traffic for any toll-free number it has the translations for.

 

If you want to take a stab at finding stuff the switch will let you dial, there's likely to be some test codes or something stuck away in there. The only disadvantage about this is it'll wait several seconds before trying to process the call, even if you put a # at the end. So it's not always easy to tell how many digits it's expecting or when it cut you off.

 

One last thing - you might notice that the latency and jitter on some of these numbers are really, really bad. That's normal; it's just how they do things. Once I was listening to the TV feed, and a talk show host started hitting a bell close enough to 2100 hertz that it thought I was trying to send a fax, so it cut off the call audio, and started trying to set up a out of band (probably T.38) fax call. If they went through the trouble to make the carrier equipment do that in the first place (though to be fair, it could've been some least cost routing people they sent the call to), they probably know it's bad.