Originally posted by local_host:
I heard that most T1s are now being delivered via 2 wire HDSL because it's cheaper? (btw- what protocol did they use before?)
Does HDSL use something called PairGain?
I heard that most T1s are now being delivered via 2 wire HDSL ... TRUE!
because it's cheaper? Yes and no... The saving of one pair (over 4-wire) is the biggest gain... which can be a $$$ savings to us Telco’s. Honestly the BIGGER reason is 2-wire can actually be MORE resilient.
btw- what protocol did they use before?
(I'm assuming you mean to deliver T1 signal)
(in chronological order of being implemented)
* DSX1 format … This is true T1 signal. Rock solid but didn’t reach anywhere for crap.
* HDSL… 4-wire HDSL with a transmit and receive.
* HDSL2 … 2-wire and actually LONGER reaching than the 1st generation of HDSL and should not be repeatered.
* HDSL4 … 4-wire that uses similar technology to HDSL2 except it splits the bandwidth to two full-duplex paths between the two pairs… and it CAN be repeatered.