i just checked the Hacking with SS7 article and links are still working and downloads available if you do not wish to use GL , you can also download required stacks from OpenSS7 .
the issue everyone is having here is that they have no idea what SS7 is nor in the Demo hack video shown in above article threy try to see whats happening everyone wants a quick way of getting it done .
Now the article explains how it will work but you need to get your own SS7 access ..
How to get SS7 Protocl Access ?
No online gateway writes "buy ss7 access" , by sigtran is a byproduct so you have read between the lines for example : BICS & Syniverse are two such services which give you ss7 . There can be many other which you can find if you try to search.
Also see : How to crack ss7, what are the Software required, links?, Pls post