19th March 2016 at 12:49
#69795
Wallis Dudhnath
Guest
DC signalling has its origins way back in telephony. Battery signalling was extensively employed in early manual systems as a method of interconnecting
switchboards. For CPE to access Switching resources DC Line Signalling was a main staple. Now we have MF4. The last “mile” of the local loop is the last part of a Digital Network that is analogue. End to end ISDN was an earlier attempt to have a full Digital Network.