Hello Balakrishnan,
Are you a Tamilian ?
When PCM Technology was developped Europe Opted to Make it as a 32 Channel System Whille US Designed 24 Channel Ssytem.
32 Channel System is called as E1.
24 Channel System is called as T1.
Becoz of the good market in US , Japaneese comapnies copied the same idea of 24 Chs PCM to Develop Systems and to use also.
Just Like any other product Japan Followerd US’s A…
Later this Tranportaion Technologies were Developped for Optical Medium.SDH Was developped for E1 and US Developped SONET to accomadate T1.
But I heard that somehow SONET is greater than SDH.( Any Info guys ??)
Regarding Analog Call:-
You are correct.But nowadays there are lot solution for Digial Subscriber Lines.Ex:DSL…
Rgds
Sunil