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Cable/Video

Ericsson Launches Ethernet DSL Push

Ericsson (Nasdaq: ERICD) is planning to launch a novel DSLAM at the ITU Telecom Asia 2002 trade show in Hong Kong next week, in a move aimed at securing a position in the emerging market for Ethernet access equipment.

Ericsson's DSLAM (DSL access multiplexer) is novel because it's so small. It's not much bigger than a cellphone and only handles 10 DSL lines. But lots of them can be packed directly into a telecom operator's main distribution frame (MDF), the piece of equipment where subscriber lines are terminated.

The result is a DSLAM that can scale from a mere 10 lines to a whopping 4,000 lines per 7-ft cabinet, according to Peter Linder, technical director of Ericsson's broadband access business unit.

The unconventional design -- traditional DSLAMs are either honking big chassis or 24- or 48-port pizza box devices -- makes it economic for operators to deploy DSL in places with fewer customers. A 10-line entry-level installation costs a mere $2,500, everything included, according to Ericsson.

At the other end of the scale, Linder says the 4,000 lines per 7-ft cabinet is "twice the density of anything else on the market". The ability to add capacity in small increments also means utilization levels can be kept high. Operators don't have to buy gear until they've got customers to use it. The bottom line is that costs can be kept to between $10 and $20 a port, compared to about $40 for traditional DSLAMs, according to Ericsson.

Ericsson's DSLAM modules are also unconventional - although not unique - in being equipped with a Gigabit Ethernet uplink to the broadband remote access server (BRAS) rather than the conventional ATM uplink. Linder says this helps eliminate a bottleneck because most ATM connections are STM1 (155 Mbit/s). He also notes that this bottleneck is becoming a big problem as broadband subscribers use higher bandwidth applications.

Pursuading incumbent carriers to go with Ericsson's Ethernet approach might be difficult, however, judging by comments made by a network architect at one such operator. Speaking anonymously, he told Light Reading he wouldn't consider Ethernet for a couple of reasons. First, it wouldn't fit in with all of his existing infrastructure, which was ATM. Second, he valued ATM's quality of service guarantees. The idea of Ethernet compensating for this by simply throwing bandwidth at the problems wouldn't work, he said. There would still be jitter problems, and curing them (the goal of the Ethernet in the First Mile Alliance (EFMA)) could make Ethernet just as costly as ATM. He also said that modern DSLAMs have higher capacity ATM uplinks - STM 4 (622 Mbit/s) and even STM16 (2.5 Gbit/s) in at least one case.

Ericsson's approach is more likely to find favor with new carriers deploying metro Ethernet technology from scratch, according to Michael Philpott, broadband communications analyst with Ovum Ltd.. This explains why Ericsson is focusing its marketing efforts on Asia and Europe, where metro Ethernet technologies have won wider acceptance than in the U.S.

Philpott thinks Ericsson has a first with its modular DSLAM design and likes the concept. However, he wonders whether incumbent operators would be comfortable installing Ericsson's DSLAM modules directly in their MDFs. There may be reasons why they wouldn't like it, he thinks.

Philpott also has reservations about another ostensibly nifty aspect of Ericsson's DSLAM modules - that individual subscriber lines can be configured as ADSL or S-ADSL (symmetrical ADSL), whether they're POTS or ISDN lines. This helps ensure high levels of utlization and also makes it easy for operators to upsell services, offering S-ADSL to ADSL subscribers who want higher upstream bandwidths.

"It looks like a good idea, but can you configure different SLAs (service level agreements?" asks Philpott. He's leery about using the same equipment to offer ADSL to home users and S-ADSL to business users because ADSL has garnered a reputation for poor reliability.

— Peter Heywood, Founding Editor, Light Reading
www.lightreading.com
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edgecore 12/4/2012 | 9:16:03 PM
re: Ericsson Launches Ethernet DSL Push
Do xDSL modems take care of turning Ethernet frames from your PC into ATM cells right at the customer premise?

Do cables modems keep the Ethernet framing all the way down to the CO?

THX

EC
rtfm 12/4/2012 | 9:16:02 PM
re: Ericsson Launches Ethernet DSL Push I think the second point has a lot of merit, in that many users treat ADSL as raw speed (connectivity), with no QoS. Most flavors today can not handle the video-level bandwidths, and incumbents, who are the prime candidates would love to keep users as voice (land-line) users as well, so issues of QoS reduce significantly.

As for ATM's benefits, I would like to know of any major provider offering SVC based QoS. The "benefits" of ATM are just a headache for operators, and many providers would love GigE, if not for incumbancy/legacy issues. That seems to be the main problem.

I think this is how such a technology can be considered. How cheaply can we link to the CPE ("last mile)? A bottleneck for QoS based "killer" apps will be bandwidth, not just QoS per se. Here, video is generally out of the question. I personally wouldn't migrate my voice (land-line) to Voice-over-DSL (IP) in the near future.

Will this work? Likely. In North America, probably not for a while. I realize this is a major over simplification, and the US is a huge country, but about the main thing we have going for us here in terms of telecom is cheap, "unlimited" local calling services. Broadband, wireless, and the like are way behind many other OECD countries. WiFi deployment is ahead of other places, but that's because it has not been treated as a telecom issue (till now).

rtfm
BobbyMax 12/4/2012 | 9:16:01 PM
re: Ericsson Launches Ethernet DSL Push Ethernet over DSL may be an interesting technology, but its adoption appears to be very doubtfulwith possible exception of very small service providers.

The important thing about Ethernet over DSL is that it follows the same ehernet framing, DSL PHY can support VDSL rates,It can reach 3000' at VDSL rate, it can be provided over a single .pair of copper
Say_Yes_2_MPLS 12/4/2012 | 9:16:00 PM
re: Ericsson Launches Ethernet DSL Push Can someone tell me what protocols are being used here and where?

Does the DSLAM take in Ethernet over DSL i.e. the work coming out of the EFM(IEEE 802.3ah)? Or does it take in ATM over DSL and strip off the ATM header and put on an Ethernet header?

Thanks
IPee 12/4/2012 | 9:15:59 PM
re: Ericsson Launches Ethernet DSL Push >> I What internet access model for residential includes QOS!!!!!!!!!!!!!!!

I would guess that the 'dumb' architecht is thinking ahead to VoIP and other QOS sensitive services. Not so dumb before they make a major investment that can not meet their future needs.
Lutie 12/4/2012 | 9:15:52 PM
re: Ericsson Launches Ethernet DSL Push Will the box have the splitter Integrated? By placing the DSLAM at the MDF, they save a bunch of money on cables/labour between DSLAM and MDF.

What would an operator think about Power at the MDF.

Would the $40 include all labour and materials or just the equipment (cable distance is a major factor).
runrabbitrun 12/4/2012 | 9:15:46 PM
re: Ericsson Launches Ethernet DSL Push >> >> I What internet access model for residential includes QOS!!!!!!!!!!!!!!!

>> I would guess that the 'dumb' architecht is thinking ahead to VoIP and other QOS sensitive services. Not so dumb before they make a major investment that can not meet their future needs.

What am I missing? DSL is not a contention technology? Why is QoS on a non-contention media required? At the customer premise they are running an Ethernet LAN to the CPE 10/100 port. The SP network could be either ATM (using RFC 1483 to translate from Ethernet to AAL5) or maintain native Ethernet. There are plenty of means for a service provider to classify a service at the DSLAM using IEEE 802.1p, 802.1Q, or DA/SA. Or if it's a routed service you've got TOS, etc. to work with.

Seems like seat of the pants engineering is going on when some one declares jitter problems out of hand without any rational explanation. All video applications I know employ jitter buffers. How much jitter is too much jitter in a network? In VoIP applications (assuming G.711 or G.729 encoding) a one-way delay of 150 msec can occur and you still get an R score of better than 8 (POTs quality).

The main question is cost. Which technology has a lower life-cycle cost. The problem for ILECs is they can't ignore the cost of replacing an embedded base, which includes (re-)training. Plus, there is the comfort factor of going what they are familiar with.
lr_fan 12/4/2012 | 9:15:41 PM
re: Ericsson Launches Ethernet DSL Push I do not know about DSL modems, but cable modems use DOCSIS. You can read all about it the Cable Labs web site. DOCSIS maintains Ethernet traffic very well, but it is a totally different Layer 1 and 2. It supports QoS and many other features. It has contention based bandwidth as well as guaranteed bandwith. And there is no "CO" in a cable company. It is called the "headend."

---------------------------------

Do xDSL modems take care of turning Ethernet frames from your PC into ATM cells right at the customer premise?

Do cables modems keep the Ethernet framing all the way down to the CO?

THX

EC
SweetOldWorld 12/4/2012 | 9:15:40 PM
re: Ericsson Launches Ethernet DSL Push runrabbit asked:
What am I missing? DSL is not a contention technology? Why is QoS on a non-contention media required? At the customer premise they are running an Ethernet LAN to the CPE 10/100 port. The SP network could be either ATM (using RFC 1483 to translate from Ethernet to AAL5) or maintain native Ethernet. There are plenty of means for a service provider to classify a service at the DSLAM using IEEE 802.1p, 802.1Q, or DA/SA. Or if it's a routed service you've got TOS, etc. to work with.

I replied:
It would have been great if there were more than 10 ports on the cust side, say 12. They could essentially oversubscribe and then rate-limit, apply QoS, etc.

-s
dietaryfiber 12/4/2012 | 9:15:40 PM
re: Ericsson Launches Ethernet DSL Push I think you are all missing the problem with product. $2500/10 = $250/port. Today DSLAMs are at less than $100/port. This also misses the cost of the E-net switch required to support this.

dietary fiber
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