djweis
join:2006-04-02
West Des Moines, IA | reply to AthlGrond
Re: Beat My Download Speed!!!
The twisted pair to the DSLAM on an ADSL circuit will always be ATM. If it's not ATM it's not ADSL. After it hits the DSLAM it can be either ethernet, ATM, frame relay, or something else. |
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AthlGrond
Premium,MVM
join:2002-04-25
Aurora, CO
 ·Comcast
| said by djweis  :The twisted pair to the DSLAM on an ADSL circuit will always be ATM. If it's not ATM it's not ADSL. After it hits the DSLAM it can be either ethernet, ATM, frame relay, or something else. Well, that's what I thought was the case. That's why I thought that there would be ATM overhead.
I really don't understand how this would be better than being connected to a CO (or a fiber fed RT) with their previous offerings, as far as overhead is concerned.
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"You are technically correct. The best kind of correct." -Bureaucrat 1.0 |
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CopperMonkey
join:2007-12-18
united state
| reply to djweis
said by AthlGrond :If I understand it correctly they don't run a fiber line directly to your NID like Verizon does with FIOS. That part (the part from their fiber network to your house) is still DSL (ADSL2+) and still uses ATM. Or do I have it all wrong? DSL doesn't function if your NID is connected by fiber. For what reason I can't remember myself, but to quote the howstuffworks site; "ADSL signals can't pass through the conversion from analog to digital and back to analog that occurs if a portion of your telephone circuit comes through fiber-optic cables."
said by djweis :The twisted pair to the DSLAM on an ADSL circuit will always be ATM. If it's not ATM it's not ADSL. After it hits the DSLAM it can be either ethernet, ATM, frame relay, or something else. I thought they ran fiber all the way up to the DSLAM/RT for the new tiers (and even the 7Mbps tier). It doesn't have to be ATM if the DSLAM/RT is fiber fed, if I'm not mistaken, and I would imagine they would avoid ATM if they could. In short they shouldn't have to run ATM for the new speed tiers. |
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dynodb
Premium,VIP
join:2004-04-21
Minneapolis, MN | ADSL is based around ATM- therefore the protocol on the local loop between your modem and the DSLAM remains the same no matter if the DSLAM is ATM or ethernet fed. |
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CopperMonkey
join:2007-12-18
united state | It doesn't have to be ATM, though. IIRC Verizon and AT&T have used PPPoE in the past for their ADSL, they might still do so but I could be mistaken. |
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AthlGrond
Premium,MVM
join:2002-04-25
Aurora, CO
·Comcast
edit:
May 6th, @10:20AM
| said by CopperMonkey :It doesn't have to be ATM, though. IIRC Verizon and AT&T have used PPPoE in the past for their ADSL, they might still do so but I could be mistaken. Qwest supports PPPoE on their regular DSL offerings, the PPPoE info just gets encapsulated by ATM. (Using PPPoE does not guarantee that ATM isn't also used.)
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"You are technically correct. The best kind of correct." -Bureaucrat 1.0 |
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adsldude
Slackware 12.2
Premium,Mod
join:2000-11-10
Colorado
Host:
All Things Unix
Qwest
Efficient
Southwest Chat
| reply to dynodb
said by dynodb :ADSL is based around ATM- therefore the protocol on the local loop between your modem and the DSLAM remains the same no matter if the DSLAM is ATM or ethernet fed. This article looks like it applies to what is going on behind the DSLAM on the network facing side. ATM can co-exist or be replaced by Metro Ethernet:
»www1.alcatel-lucent.com/bnd/app_···h_an.pdf
Does the article fit what Qwest is beginning to deploy? |
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CopperMonkey
join:2007-12-18
united state
| reply to AthlGrond
Yes, that's been noted on the previous page by ewth8tr, whom I noticed you had replied to; seems he's right on the money.
said by AthlGrond :Qwest supports PPPoE on their regular DSL offerings, the PPPoE info just gets encapsulated by ATM. (Using PPPoE does not guarantee that ATM isn't also used.) Then it would be the other way around for Verizon/AT&T, right? |
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AthlGrond
Premium,MVM
join:2002-04-25
Aurora, CO
·Comcast
| said by CopperMonkey :said by AthlGrond :Qwest supports PPPoE on their regular DSL offerings, the PPPoE info just gets encapsulated by ATM. (Using PPPoE does not guarantee that ATM isn't also used.) Then it would be the other way around for Verizon/AT&T, right? I'm not saying that they don't use PPPoE without ATM (I don't know if they do or don't), my point was that their use of PPPoE doesn't rule out their use of ATM which if I understood you correctly was your point (that the use of PPPoE proves that they don't use ATM).
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"You are technically correct. The best kind of correct." -Bureaucrat 1.0 |
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CopperMonkey
join:2007-12-18
united state | It wasn't clear, but my point, aside from that they do use the Qwest Metropolitan Optical Ethernet network for the 12 and 20 meg tiers, was that in lower speed tiers they don't HAVE to use ATM. They just choose to. |
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AthlGrond
Premium,MVM
join:2002-04-25
Aurora, CO | Ah! Thanks.  |
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