SDSL

Network problem solving and tweaks
Post Reply
jee
Registered User
Posts: 19336
Joined: 03 Jun 2003, 02:00
Location: a hole so deep...

SDSL

Post by jee »

Hi Guys and gals

Can someone please give me a quick lecture (in pcf language :) ) on SDSL?

Has anyone been using Telcum's new uncapped ADSL?
"Integrity" and "integer" both contain a Latin root meaning "whole; complete." The root sense, then, is that people may be said to be acting with integrity when their beliefs, words, and actions have a sense of unity or wholeness.
RuadRauFlessa
Registered User
Posts: 20576
Joined: 19 Sep 2003, 02:00
Location: Bloodbank

Re: SDSL

Post by RuadRauFlessa »

http://en.wikipedia.org/wiki/Symmetric_ ... riber_line

1) In the wider sense it is a collection of Internet access technologies based on DSL that offer symmetric bandwidth upstream and downstream. It is considered the opposite of asymmetric digital subscriber line (ADSL) technologies where the upstream bandwidth is lower than the downstream bandwidth.
2) In the narrow sense SDSL is a particular DSL variant that supports data only on a single line and does not support analog calls.

So it does not support voice but up and downstream has the same bandwidth. On a 4Mb ADSL you have a 3.5Mb Down and 512kb Up stream data connection and you can still make phone calls while transferring data. ADSL has a steep contention ratio as a rule where SDSL does not. It could be that Telescum does employ the same contention ratios but I highly doubt it
:rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock:
Spoiler (show)
Intel Core i7-2600k @ 3.4GHz
Corsair Vengence 2x4GB DDR3 2000MHz
Thermaltake Toughpower 850W
ASUS nVidia GTX560 1GB
CoolerMaster HAF 932
DeathStrike
Registered User
Posts: 2663
Joined: 29 Jul 2004, 02:00
Location: hidden deep in the depths of the underworld is my home.
Contact:

Re: SDSL

Post by DeathStrike »

wait...

Is telscum's uncapped SDSL?

or am i just reading this wrong?

Does any ISP offer SDSL? dam i would love that.. never use my telkom line for calls anyway...
Spoiler: (show)
Image
SIG by HMAN 8)
Member of The Pride Of Darkness
DeathStrike on Twitter
About me
Spoiler: (show)
Asus P5KPL-CM motherboard, 4 GIG RAM, Q6600 @ 2.88GHz (Thanks Anthro), GeForce 8600GT, Samsung 2333 23" + CRT 17" Monitors. 500GB + 1.5TB HDD, Compro TV tuner, 350 WATT PSU
RuadRauFlessa
Registered User
Posts: 20576
Joined: 19 Sep 2003, 02:00
Location: Bloodbank

Re: SDSL

Post by RuadRauFlessa »

DeathStrike wrote:wait...

Is telscum's uncapped SDSL?

or am i just reading this wrong?

Does any ISP offer SDSL? dam i would love that.. never use my telkom line for calls anyway...
There are people that do offer it but it is a very selected few and not all over the country either. Dunno why as it is actually cheaper to roll out.
:rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock:
Spoiler (show)
Intel Core i7-2600k @ 3.4GHz
Corsair Vengence 2x4GB DDR3 2000MHz
Thermaltake Toughpower 850W
ASUS nVidia GTX560 1GB
CoolerMaster HAF 932
KALSTER
Forum Moderator
Posts: 5439
Joined: 12 Oct 2008, 02:08

Re: SDSL

Post by KALSTER »

..But you pay through your nose for it.
"It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
Intel i5 2500; AsRock Z77 Extreme 4; Asus GTX580; 4x 2GB DDR3 1333; Intel 520 240GB SSD + 2x WD 3TB + 2TB Samsung; Samsung 22X DVD/RW; 23" LG W2343T-PF; Huntkey 700W
User avatar
hamin_aus
Forum Moderator
Posts: 18363
Joined: 28 Aug 2003, 02:00
Processor: Intel i7 3770K
Motherboard: GA-Z77X-UP4 TH
Graphics card: Galax GTX1080
Memory: 32GB G.Skill Ripjaws
Location: Where beer does flow and men chunder
Contact:

Re: SDSL

Post by hamin_aus »

That's been around for ages in the rest of the world....

It's called NDSL or Naked DSL here.

You buy a line with no analogue service and most people just get a VOIP service to go with it - if they get a phone at all.
Actually works out cheaper here.
Image
KALSTER
Forum Moderator
Posts: 5439
Joined: 12 Oct 2008, 02:08

Re: SDSL

Post by KALSTER »

Is naked DSL synchronous though?
"It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
Intel i5 2500; AsRock Z77 Extreme 4; Asus GTX580; 4x 2GB DDR3 1333; Intel 520 240GB SSD + 2x WD 3TB + 2TB Samsung; Samsung 22X DVD/RW; 23" LG W2343T-PF; Huntkey 700W
User avatar
hamin_aus
Forum Moderator
Posts: 18363
Joined: 28 Aug 2003, 02:00
Processor: Intel i7 3770K
Motherboard: GA-Z77X-UP4 TH
Graphics card: Galax GTX1080
Memory: 32GB G.Skill Ripjaws
Location: Where beer does flow and men chunder
Contact:

Re: SDSL

Post by hamin_aus »

KALSTER wrote:Is naked DSL synchronous though?
No, but then neither is SDSL - the S stand for Symmetrical :idea:

It's basically where they use your whole twisted copper pairs frequency range for data only, so you cant get voice over it. With this extra bit of space on the line for data they can send and receive data at lower speeds at the same time, making it for all intents and purposes synchronous.

Naked uses the usual DSL range of your copper and just doesn't make use of the voice range, and doesn't charge you for voice.

It's worth noting that SDSL still cant overcome the upload threshold of DSL, so it it will never be faster than 2Mbps both ways...
And knowing Telkom they will give you a pipe ridiculously slower than that.

The only benefit with it is that because it's a smaller pipe than traditional DSL there is less contention, so users on an SDSL network can get pretty close to the advertised speed all the time - even when others are using it consistently, making it attractive to businesses.

The ISP I work for in Aus offers it, it's called SHDSL here :arrow: http://www.iinet.net.au/business/shdsl/overview.html

We also have something called Bonded DSL. Where you basilcally pay for 2 DSL lines and they bridge your 2 ports on the exchange effectively doubling your speed.
Image
DeathStrike
Registered User
Posts: 2663
Joined: 29 Jul 2004, 02:00
Location: hidden deep in the depths of the underworld is my home.
Contact:

Re: SDSL

Post by DeathStrike »

jamin_za wrote:
KALSTER wrote:We also have something called Bonded DSL. Where you basilcally pay for 2 DSL lines and they bridge your 2 ports on the exchange effectively doubling your speed.
Yeah my work has this... currently using two bonded 10Mbps lines and a wireless direct link to our servers... which means even if the adsl goes down we can still access our servers.
Spoiler: (show)
Image
SIG by HMAN 8)
Member of The Pride Of Darkness
DeathStrike on Twitter
About me
Spoiler: (show)
Asus P5KPL-CM motherboard, 4 GIG RAM, Q6600 @ 2.88GHz (Thanks Anthro), GeForce 8600GT, Samsung 2333 23" + CRT 17" Monitors. 500GB + 1.5TB HDD, Compro TV tuner, 350 WATT PSU
KALSTER
Forum Moderator
Posts: 5439
Joined: 12 Oct 2008, 02:08

Re: SDSL

Post by KALSTER »

No, but then neither is SDSL - the S stand for Symmetrical
Damn, that's what I meant.
It's worth noting that SDSL still cant overcome the upload threshold of DSL, so it it will never be faster than 2Mbps both ways...
And knowing Telkom they will give you a pipe ridiculously slower than that.
But why though? Is it a hardware limitation at the user side?
"It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
Intel i5 2500; AsRock Z77 Extreme 4; Asus GTX580; 4x 2GB DDR3 1333; Intel 520 240GB SSD + 2x WD 3TB + 2TB Samsung; Samsung 22X DVD/RW; 23" LG W2343T-PF; Huntkey 700W
RuadRauFlessa
Registered User
Posts: 20576
Joined: 19 Sep 2003, 02:00
Location: Bloodbank

Re: SDSL

Post by RuadRauFlessa »

KALSTER wrote:
No, but then neither is SDSL - the S stand for Symmetrical
Damn, that's what I meant.
It's worth noting that SDSL still cant overcome the upload threshold of DSL, so it it will never be faster than 2Mbps both ways...
And knowing Telkom they will give you a pipe ridiculously slower than that.
But why though? Is it a hardware limitation at the user side?
Nope... it is a situation of being able to send in one direction at a time. Remember that the single channel is used for both up and down.
:rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock:
Spoiler (show)
Intel Core i7-2600k @ 3.4GHz
Corsair Vengence 2x4GB DDR3 2000MHz
Thermaltake Toughpower 850W
ASUS nVidia GTX560 1GB
CoolerMaster HAF 932
User avatar
hamin_aus
Forum Moderator
Posts: 18363
Joined: 28 Aug 2003, 02:00
Processor: Intel i7 3770K
Motherboard: GA-Z77X-UP4 TH
Graphics card: Galax GTX1080
Memory: 32GB G.Skill Ripjaws
Location: Where beer does flow and men chunder
Contact:

Re: SDSL

Post by hamin_aus »

The slow upload capability of all DSL lines is a hardware limitation that wont be overcome until we all have exchanges in our homes :P

SDSL does not in fact overcome this at all. It cheats and caps the download speed at the same as the upload speed - effectively if you use SDSL, you download slower than you would on ADSL.

To answer jee a bit more:

While this might not sound ideal, consider being a business and needing to send as much data as you receive.
Your Telkom Business ADSL line can do 4mb down, but only 512K up... But you don't see anything near that in the real world due to contention etc.
Wouldnt it be better to have a 1mb line going both ways :?: Many businesses in this position would prefer that.

And as I have also mentioned, SDSL needs it's own dedicated network since it's a slightly different implementation of the DSL standard and doesnt play nicely with ADSL. That means your line runs on a network with far fewer users than standard ADSL, and the fact that everyone on it connects at lower speeds further lessons the strain on the network made by bandwidth hogs and leeches. Meaning that you can pretty much be sure you will be getting as close to the maximum line speed advertised for the service as your physical setup allows.

Make sense :?:
Image
jee
Registered User
Posts: 19336
Joined: 03 Jun 2003, 02:00
Location: a hole so deep...

Re: SDSL

Post by jee »

ta jamin :)
"Integrity" and "integer" both contain a Latin root meaning "whole; complete." The root sense, then, is that people may be said to be acting with integrity when their beliefs, words, and actions have a sense of unity or wholeness.
Anakha56
Forum Administrator
Posts: 22136
Joined: 14 Jun 2004, 02:00
Processor: Ryzen 1700K
Motherboard: Asus X370
Graphics card: Asus 1060 Strix
Memory: 16GB RAM
Location: Where Google says

Re: SDSL

Post by Anakha56 »

Thanks for the info hamin. Was a good read :).
JUSTICE, n A commodity which is a more or less adulterated condition the State sells to the citizen as a reward for his allegiance, taxes and personal service.
KALSTER
Forum Moderator
Posts: 5439
Joined: 12 Oct 2008, 02:08

Re: SDSL

Post by KALSTER »

Good on 'ye mate.
"It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
Intel i5 2500; AsRock Z77 Extreme 4; Asus GTX580; 4x 2GB DDR3 1333; Intel 520 240GB SSD + 2x WD 3TB + 2TB Samsung; Samsung 22X DVD/RW; 23" LG W2343T-PF; Huntkey 700W
Post Reply