Kitz ADSL Broadband Information
adsl spacer  
Support this site
Home Broadband ISPs Tech Routers Wiki Forum
 
     
   Compare ISP   Rate your ISP
   Glossary   Glossary
 
Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: Britannia article  (Read 9384 times)

Weaver

  • Senior Kitizen
  • ******
  • Posts: 11459
  • Retd s/w dev; A&A; 4x7km ADSL2 lines; Firebrick
Britannia article
« on: October 14, 2019, 01:02:33 AM »

In this article https://www.britannica.com/technology/modem/DSL-modems should the standard for ADSL not be G.992.1 ? Not G.991.2 as stated ? Or am I missing something? Was the latter earlier? The thing is, it does explicitly mention asymmetrical rates in the article.
Logged

burakkucat

  • Respected
  • Senior Kitizen
  • *
  • Posts: 38300
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: Britannia article
« Reply #1 on: October 14, 2019, 01:37:56 AM »

ADSL   is ITU-T G.992.1
ADSL2  is ITU-T G.992.3
ADSL2+ is ITU-T G.992.5
VDSL   is ITU-T G.993.1
VDSL2  is ITU-T G.993.2


  :graduate:
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

sevenlayermuddle

  • Helpful
  • Addicted Kitizen
  • *
  • Posts: 5369
Re: Britannia article
« Reply #2 on: October 14, 2019, 09:49:27 AM »

Not sure the comparison with T1 is helpful.

Quote
DSL systems carry digital signals over the twisted-pair local loop using methods analogous to those used in the T1 digital carrier system to transmit 1.544 Mbps in one direction through the telephone network.

T1 is an entirely different technology, using TDM,  not DMT.  The USP of T1, from my hazy recollection, is the ability to multiplex 24 discreet timeslots (32 for E1), each of which has individual bandwidth as required for a single voice channel, onto a single line.
Logged

dee.jay

  • ISP Rep
  • Reg Member
  • *
  • Posts: 952
Re: Britannia article
« Reply #3 on: October 14, 2019, 08:58:46 PM »

I have experience with E1 (European equivalent of T1) for voice, used to operate a Cisco CallManager over an E1 ISDN PRI interface on a Cisco 2600 router.

We had 16 channels, so could make that many external calls at once out to the PSTN, IIRC.

Fun times.
Logged
Starlink and AAISP L2TP combo routed by opnSense on proxmox

burakkucat

  • Respected
  • Senior Kitizen
  • *
  • Posts: 38300
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: Britannia article
« Reply #4 on: October 14, 2019, 09:19:11 PM »

I have now read that article all the way from the Introduction to the end and my feeling is the author has somewhat "lost his way".  :-\  :-X
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

sevenlayermuddle

  • Helpful
  • Addicted Kitizen
  • *
  • Posts: 5369
Re: Britannia article
« Reply #5 on: October 14, 2019, 09:32:53 PM »

E1 is not just Europe, iirc pretty much everywhere uses E1, other than North America or Japan.

I have now read that article all the way from the Introduction to the end and my feeling is the author has somewhat "lost his way".  :-\  :-X

Your attention span is better than mine, I failed to get very far.   But your conclusion does not surprise me. :)
Logged

burakkucat

  • Respected
  • Senior Kitizen
  • *
  • Posts: 38300
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: Britannia article
« Reply #6 on: October 14, 2019, 10:33:37 PM »

But your conclusion does not surprise me. :)

b*cat bows to 7LM in acknowledgement of the compliment.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

Weaver

  • Senior Kitizen
  • ******
  • Posts: 11459
  • Retd s/w dev; A&A; 4x7km ADSL2 lines; Firebrick
Re: Britannia article
« Reply #7 on: October 15, 2019, 12:21:08 AM »

@burakkucat - agreed - so it wasn’t just me then?
Logged

burakkucat

  • Respected
  • Senior Kitizen
  • *
  • Posts: 38300
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: Britannia article
« Reply #8 on: October 15, 2019, 12:23:28 AM »

Agreed. No, it wasn't you.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

niemand

  • Kitizen
  • ****
  • Posts: 1836
Re: Britannia article
« Reply #9 on: January 07, 2020, 01:20:33 AM »

Quote
By varying the number of carriers actually used, DMT modulation may be made rate-adaptive

So nothing to do with changing the modulation order used in individual tones, just on or off. Right-o.
Logged