Why TDM does not scale
PSTNs traditionally (Graham Bell Era) stuff a single call on a single cable pair … and charge for 1 pair!
PSTNs then stuffed multiple calls on a single cable pair using Time Division Multiplexing (TDM) and charge as multiple pairs!!
- BRI, PRI, ISDN, E1 T1 etc are all TDM technologies with diverse switching and Timing technologies
PSTNs are now stuffing almost all calls into IP and they still keep the entire honey pot
TDM is wasteful. Cannot utilize time slots carrying a period of silence in conversations
VOIP is incompatible with the PSTN’s charging model!
TDM introduces complex settlement systems, rendered obsolete by IP