Why does FTTN Fusion need X2 to increase speed?

[Duncan]

I've read here about VDSL circuits connected directly to the CO (not through a VRAD) that can achieve 50+Mbps speeds, using a singe-pair wire loop. Yet the FTTN Fusion customers who want better than ~20Mbps have to do so by provisioning a second loop as part of the X2 service.

Setting aside the pricing tiers for faster service as delivered over Uverse, why can't AT&T simple 'open the spigot' on a single-pair connection if the customer wants a higher speed (and is close enough to the VRAD)? It seems like a waste of resources to use a second wire loop and bonded modem when, as far as I can tell, the single loop should, in many cases, be capable of a higher speed on its own.

[m2m3]

Historically and technically speaking, the xDSLxxx technologies are limited specifcally by distance and line quality and conditions.

Since ATT has ownership to the local hardware in many areas, they can basically control their territory and prevent others like Sonic from being able to impose their will on the localities; of course, that is due to government regulations dating back to 1996 specifically. If all ISP's are able to compete equally, we probably wouldn't be having this conversation, now would we?

Simply put, ATT is in it for their own good. In many ways, you shouldn't blame them, given the advantageous conditions they have been granted. The same goes for cable companies. Just don't rely upon ATT to open their pipeline like Sonic for max speeds regardless of distance. They won't normally maximize their bandwidth for individuals; so, they offer tier pricing to maximize profits and sucker their clients. I have friends who are still on 3 Mb/s lines who are at 8,000 feet from the CO and have no RT or VRAD available. Why is that when we are in a very heavy populated area such as Glendale, Ca., 200,000+ population and are very close to Downtown LA, Hollywood, Burbank, Pasadena, etc.? If you can't get very high speeds in this metropolis, then something is definitely rotten in Denmark. You would think that such a concentration of people would be getting upwards of 20 Mb/s on average regardless of where they live.

[Duncan]

I understand that the business agreement between AT&T and Sonic determines the speeds available at any given pricing tier, but I'm more curious about the actual implementation.

Why use up two ports on a VRAD if one is capable of higher speed?

(And as it is, Sonic's X2 service over FTTN demonstrates that a single port is already capable of higher speed, since the nominal speed jumps from ~18Mbps to ~45 Mbps if you order the second link, not just to ~36Mbps.)

[thulsa_doom]

Different AT&T equipment can handle different speeds per copper pair. When we ask AT&T to deliver a 45mbps circuit (typically resulting in 50mbps performance) they deliver it via however many pairs they need to, typically two.

[polpo]

I have 45Mbps service (through DSLExtreme; I'll move back to sonic as soon as my contract is up!), and my modem says the sync rate on my two pairs are 60Mbps and 72Mbps. I think it's just how AT&T does things; to keep deployments consistent as possible. I would be ecstatic if they could "open the spigot" on my two pairs.

[Guest]

From reports of recent X2 installations, it sounds like some people are getting their X2 speeds from a single pair. So is this a case-by-case situation where some VRADs support higher single-line speeds, and others do not?

(And I don't think it can be attributed to distance, since numerous people have reported being <1000 ft. to the VRAD yet still require two pairs.)

[dane]

From reports of recent X2 installations, it sounds like some people are getting their X2 speeds from a single pair. So is this a case-by-case situation where some VRADs support higher single-line speeds, and others do not?

(And I don't think it can be attributed to distance, since numerous people have reported being <1000 ft. to the VRAD yet still require two pairs.)

Distance, line quality and interference are all factors. AT&T will deploy one or two pairs as needed to achieve the X1 (up to 20Mbps) and X2 (up to 50Mbps) speed. So you might see X1 tier customers with two pair, and X2 tier customers with just one, depending upon distance and technology availability. With FTTN, it's really a speed tier maximum, not a technology or a consistent line quantity identifier.

With standard Fusion X1 and X2, it's one line or two, simple as that. Of course close in this could be VDSL at up to 75Mbps per line, versus further away it could be 5Mbps per line.

[Guest]

AT&T will deploy one or two pairs as needed to achieve the X1 (up to 20Mbps) and X2 (up to 50Mbps) speed. So you might see X1 tier customers with two pair, and X2 tier customers with just one, depending upon distance and technology availability. With FTTN, it's really a speed tier maximum, not a technology or a consistent line quantity identifier.

Thanks for the clarification.

And I suppose to further complicate things, depending on which permutation of service and capable pairs one might have, there are different modem models involved as well.

[dane]

AT&T will deploy one or two pairs as needed to achieve the X1 (up to 20Mbps) and X2 (up to 50Mbps) speed. So you might see X1 tier customers with two pair, and X2 tier customers with just one, depending upon distance and technology availability. With FTTN, it's really a speed tier maximum, not a technology or a consistent line quantity identifier.

Thanks for the clarification.

And I suppose to further complicate things, depending on which permutation of service and capable pairs one might have, there are different modem models involved as well.

Yep, of course. But from the customer's perspective it's simple: X1 delivers up to 20Mbps, X2 delivers up to 50. Exactly how and with what equipment varies, but doesn't matter to most people.

[Davidt]

Hi

I have been a loyal customer for 4.5 years with sonic. I have single pair fusion with only 20 Meg's . I was try to get my neighbors to sign up DSL and website say I am 892 feet from co... I call tech support and asked I can get a higher speed. He say I have to upgrade fx2... No speed higher on my current line.. I need some help here.. I do have webcast in my building in 120 meg is only $550 a year...

Thanks