Let’s see if we can fix that there corn-fusion for ya.
Originally posted by local_host:
I thought ALL bandwidth services connect via a DSLAM either located in the CO or a remote DSLAM standing alone somewhere outside near a curb.
“ALL bandwidth services connect to DSLAMs†is WAY too broad to be correct. ADSL or SDSL (where offered) do in fact ALL connect to DLSAMs in the C.O. (or remote terminals) … but others such service that could be called “bandwidth†such as Metro Ethernet or Integrated Access Service (the data part) do not.
Myself I wouldn’t technically refer to a T1 as really a “bandwidth service†… That’s a fixed pipe in my opinion. In cases where you’d be getting a data service from an ISP via a T1, those connect to Frame and/or ATM switches normally rather than a DSLAM.
Originally posted by local_host:
Does HDSL work the same way as ADSL in that it uses a higher frequency (atop the phone service frequency) that was once idle, until someone figured out how to make use of it.....
HDSL and ADSL work over a high-freq and that’s really where the similarities stop… ADSL does ride over voice-trunks or POTS (plain old telephone service) at frequencies high enough not to interfere with voice communication or signaling… Whereas HDSL would never be superimposed over a POTS line. HDSL has a single use of delivering T1 over copper… And the copper pairs it uses are strictly dedicated to THAT T1 circuit.
Originally posted by local_host:
Btw, when did the 1st generation of HDSL come along?
Myself I’m not exactly sure… I first heard of it myself about 7 years ago… but at that time I was working in a group that was dealing exclusively with DS0/sub-rate circuits. At that point in time I wasn’t paying too awful much attention to it. I have some older books here… I’ll see if I can come up with an approximate year.
