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Even when the phones on both ends use IP calling technology, the interconnection between phone companies is usually not IP.
by supertrope 11mo ago
Even when the phones on both ends use IP calling technology, the interconnection between phone companies is usually not IP.
- kristofferR 11mo agoFrom what I've read that tends to change when the phone companies in question have shut off 2G and 3G though. The only reason to keep using SS7 is for intercompatibility with legacy networks who still have 2G or 3G devices on them.