How ADSL2+ and VDSL2 are different?

[IvanP91v]

Hello

I know that VDSL2 is faster than ADSL2+, and that it uses different modems, etc.

But what Im wondering about is, how are they different?

-Do they both connect to the same DSLAM?
-Do they use different routes to get to the ISP?
-Do they both use the same line after the node? (VDSL on Fibre optic and ADSL on ? )
-Are IPs and hostnames different for ADSL and VDSL connections? (as in entirely different IP ranges)

And other background information on the two types of connections.

All im able to find is that VDSL is faster, allows for triple play and thats it.
But what I need to know is the technical background information.

Thanks in advance

 

[ScottMac]

In the case of AT&T, VDSL2 is using Ethernet framing over VDSL2, and ADSL2+ is still using an ATM-based transport over ADSL2+ signaling.

They go to different types of DSLAMs

They probably take the same route to the peering point (since they both would aggregate back in the same CO ... different COs "probably" will have different routes.

Both would be fiber back to the CO and fiber from the CO upstream

Likely to be different dynamic address blocks. Again, for neighborhoods with both, they would be migrating to the IPDSLAM product. Once all the users have migrated (voluntarily or otherwise), then ADSL goes away. That reduces the equipment in the field and management resources.

 

[drebo]

Actually, AT&T is deploying new IP-based ADSL2+ DSLAMs in some neighborhoods. Depends on the average length of wire between where the RT is and the homes. Some places, the MINIMUM range is longer than VDSL can reliably do.

When I bought new Uverse two years ago, it was deployed on ADSL2+ on their new IP DSLAMs. Most DSLAMs can support both types of line cards.

 

[Mark R]

Hello
I know that VDSL2 is faster than ADSL2+, and that it uses different modems, etc.

But what Im wondering about is, how are they different?

The overall system design is similar.

The provider has a DSLAM, which has a high-speed digital (ethernet or ATM, usually fiber) connection to their core network.

From the DSLAM to the subscriber's premises, is a normal twisted pair copper telephone cable.

Under ADSL, the DSLAM would be located at a telephone exchange or similar site.

Because VDSL can only tolerate a very short copper connection to the subscriber's premises (no more than 300 meters or so), in a VDSL installation, the provider will install a DSLAM inside a roadside cabinet. They will then have a fiber connection from the box to their main network. This type of network design is often called FTTC (fiber to the cabinet).

VDSL and ADSL DSLAMs are different. The two systems use different communications signals. Both systems work by using a number of different "channels" for communication on the same wire, very similar to the way that different radio stations use different channels on the same air.

A typical ADSL connection might use 200 channels on a single wire. Each data packet is broken up into 200 separate streams, and each stream gets transmitted on its own channel. The DSLAM and modem constant monitor the quality of the signal on each channel, and shuffle bits around as necessary. A channel with a very clear signal might take 6 or 8 bits in one go, whereas a weak channel with lots of interference might only get 1 bit.

VDSL2 connections use more channels and operate the channels at a higher baud rate - up to about 4000 channels at 8000 baud - in order to get more speed. VDSL2 also has a variety of improvements available (e.g. active noise cancellation) in order to make the best use of the customer wiring available.

 

[ScottMac]

The overall system design is similar.

The provider has a DSLAM, which has a high-speed digital (ethernet or ATM, usually fiber) connection to their core network.

From the DSLAM to the subscriber's premises, is a normal twisted pair copper telephone cable.

Under ADSL, the DSLAM would be located at a telephone exchange or similar site.

Because VDSL can only tolerate a very short copper connection to the subscriber's premises (no more than 300 meters or so), in a VDSL installation, the provider will install a DSLAM inside a roadside cabinet. They will then have a fiber connection from the box to their main network. This type of network design is often called FTTC (fiber to the cabinet).

VDSL and ADSL DSLAMs are different. The two systems use different communications signals. Both systems work by using a number of different "channels" for communication on the same wire, very similar to the way that different radio stations use different channels on the same air.

A typical ADSL connection might use 200 channels on a single wire. Each data packet is broken up into 200 separate streams, and each stream gets transmitted on its own channel. The DSLAM and modem constant monitor the quality of the signal on each channel, and shuffle bits around as necessary. A channel with a very clear signal might take 6 or 8 bits in one go, whereas a weak channel with lots of interference might only get 1 bit.

VDSL2 connections use more channels and operate the channels at a higher baud rate - up to about 4000 channels at 8000 baud - in order to get more speed. VDSL2 also has a variety of improvements available (e.g. active noise cancellation) in order to make the best use of the customer wiring available.

U-verse triple-play (TV, Internet, VoIP) goes to ~3000 feet (~1000 yards) on a single pair with Max available Bit Rate usually in the neighborhood of 30-35Mbps. With two bonded pair, the distance can be extended to over 5000 feet and still well above 30Mbps (or higher data rates at closer distances) using VDSL2.

 

[IvanP91v]

These were the exact answers I was looking for. Most of the information I found online was fairly limited in explaining inner workings of the two connections.

Thank you very much for the replies.

 

[Oric]

Best vdsl2 modem specs ?

 

[IvanP91v]

Sorry for bumping an older topic. But I got another question about DSL.

Its probably a stupid question, but anyway...

If I am buying my internet from a reseller/3rd party provider, do I connect to their DSLAM or to the DSLAM of the company that sells their bandwidth to the 3rd party?

For example if I pay monthly to company X and I know that Bell Canada (ADSL/VDSL) provider owns the lines, do I connect to some DSLAM owned by company X or Bell Canada's DSLAMs? (Was thinking that maybe the fiber optic links between DSLAMs are owned by Bell Canada, i dunno)

My IP/hostname shows the name of the reseller company.


Thanks in advance
--

@ Oric: Best vdsl2 modem specs ?

My only VDSL2 modem choices are :
http://www.dslreports.com/forum/r26672440-sagemcom-f-st-2864-internal-pics-info Sagecom F@ST 2864
and
http://www.zyxel.com/products_services/vsg1432_b101.shtml?t=p

 

[SecurityTheatre]

Sorry for bumping an older topic. But I got another question about DSL.

Its probably a stupid question, but anyway...

If I am buying my internet from a reseller/3rd party provider, do I connect to their DSLAM or to the DSLAM of the company that sells their bandwidth to the 3rd party?

For example if I pay monthly to company X and I know that Bell Canada (ADSL/VDSL) provider owns the lines, do I connect to some DSLAM owned by company X or Bell Canada's DSLAMs? (Was thinking that maybe the fiber optic links between DSLAMs are owned by Bell Canada, i dunno)

My IP/hostname shows the name of the reseller company.


Thanks in advance

In general, all of the physical hardware is owned by the telco (Bell) and they simply connect the other end of the line to a pipe owned by the reseller.

The reseller gives you the IP and provides network connectivity over the telco's lines and they pay the telco in aggregate for the lease of all the physical links they use.

Therefore, OSI Layer 1 (physical link) is owned by the telco. OSI Layer 3 (IP Layer) is all run by the reseller. I'm pretty sure Layer 2 is mostly handled by the telco, but that may depend on the type of line....

 

[drebo]

It could be either, depending on the interconnect agreement the company has.

I don't know about other countries, but in the US, people with the proper agreement can lease the unbundled loop (called a UNE, the actual physical copper pair from the CO to the house) and run it into their own DSLAM collocated at or interconnected with the CO.

The other option that Verizon and AT&T had made available (and some larger CLECs do it, too) was to give you an ATM aggregation circuit (or an Ethernet aggregation circuit) and bridge their DSLAM to you via PVCs or VLANs. In this way, you don't need an interconnect agreement. AT&T will be ending this practice relatively soon, however. I don't know if Verizon will or not.

So, the answer is that only the Telco you're buying from really knows. The line always belongs to the ILEC, but the DSLAM could either be the ILECs or not.

 

[Cabletek]

Are you talkign about adsl or adsl2+, i did no tthink too many telcos went with ADSL2.

ADSL2+ - http://en.wikipedia.org/wiki/Asymmetric_digital_subscriber_line_2_plus
ADSL2 - http://en.wikipedia.org/wiki/Asymmetric_digital_subscriber_line_2
VDSL2 - http://en.wikipedia.org/wiki/Very-high-bit-rate_digital_subscriber_line_2

Century link is currently referencing the term VDSL2+, which I do not see listed as a type at Wikipedia, I imagine its a term of their own making to make them look more up to date to techies, more than anything.

The basic difference is the frequencies and channel width they use from what I can tell with brief reading.

ADSL2+ extends the capability of basic ADSL by doubling the number of downstream channels. The data rates can be as high as 24 Mbit/s downstream and up to 1.4 Mbit/s upstream depending on the distance from the DSLAM to the customer's premises.

VDSL2 is an enhancement to very-high-bit-rate digital subscriber line (VDSL), Recommendation G.993.1. It permits the transmission of asymmetric and symmetric aggregate data rates up to 200 Mbit/s downstream and upstream on twisted pairs using a bandwidth up to 30 MHz. Bonding (ITU-T G.998.x) may be used to combine multiple wire pairs to increase available capacity, or extend the copper network's reach.

The basics, lots more useful info for say a report are in the links provided, and you can have an actual source to document.

 

[JackMDS]

Sorry for bumping an older topic. But I got another question about DSL.

If I am buying my internet from a reseller/3rd party provider, do I connect to their DSLAM or to the DSLAM of the company that sells their bandwidth to the 3rd party?
--

Every case can have its own arrangement. In most cases 3rd party providers are just a business arrangement. The Original ISP give a lower price to the 3rd party for buying many accounts and by doing so avoid the trouble of direct support to "ignorant" users.

Usually when it comes to the actual technical work (like repairing DSLAM, Lines. etc.) it done by the original ISP.

Where I am at it is Not uncommon that Verizon people will repair DSL system up to your door while you are actually a subscriber of ATT.

I.e., when you complain to ATT they call Verizon and ask them to take care of the problem.

That said, to find out what is going on in your neck of the wood "snoop" around find some neighbors that uses the services and ask them.



i

 

[IvanP91v]

Ah, okay, so there multiple ways this agreement between companies could work.

It seems like in my case its the arrengment that JackMDS described above.
Since Bell technicians come over whenever there is a problem or to install something while I pay the reseller about $15-20 dollars per month less than I would pay Bell.

Thanks again for the help guys.