Hi!!
It seems like the prices are highly misbalanced, but always the SDSL
service is more expensive than the ADSL service (considering equal
connection speeds).
Why?
At same connection rate the SDSL offers the same rate for upload and
download. You asked who cares? I can tell you that business people
cares. The SDSL service is intended for businesses or people who use
the Internet connection for sending e-mails, videoconferencing,
netmeeting, web hosting, and business to business applications. That
is applications where the use of upload direction is as much important
as download is.
Since the contention rate of SDSL is 1:1, at a same connection speed
SDSL can carry more info on a single wire of twisted-pair cable.
Other advantage, more useful for business people and companies, is
that you will have a fixed IP with SDSL:
"Q: SDSL or ADSL?
A: Although ADSL is less expensive than SDSL, it is designed for the
home user. If you are going to be operating servers or conducting
business, SDSL makes more sense, not only because the maximum upstream
speed is faster than ADSL, but because your DSL provider is more
likely to understand your needs, give you a fixed IP and be more
responsive to technical problems."
"SDSL or ADSL?":
http://www.business-dsl-service.com/showquestion_dsl_faq.php?qid=32
Commonly the SDSL services has a lot of additionals that fit the
business' needs, this explain in part the higher costs. See for
example the following comparison of available DSL plans and DSL
features at "Covad Broadband Information and Services":
http://broadband.covad.com/products/broadband/broadband.shtml?show=t1&ap=var_acclaimdsl
And as jmfaure said, SDSL performance is guaranteed:
"SDSL (Single-line DSL) - is apparently the same thing as HDSL with a
single line, carrying 1.544 Mbps (U.S. and Canada) or 2.048 Mbps
(Europe) each direction on a duplex line. It is considered to be the
"business grade" DSL because of its symmetric speeds. SDSL is slower
than ADSL but usually marketed with Service Level Agreement (SLA) such
as the network will be guaranteed up for 99.5%, and there will be a
24-hour response time for every problem."
From "DSL Varieties":
http://www.dsl-isp-guide.com/dslvarieties.htm
SDSL service requires a dedicated telephone line because, unlike ADSL,
telephone and fax services cannot share a line with SDSL service. The
intallation of this line is mostly included in the installation costs
and you cannot use this line for phone calls, this explains the higher
instalation costs. Also the SDSL modem is not the same than the ADSL
modem, so you will ask the provider the cost and conditions of the use
of it.
I hope that the above paragraphs helps you to understand the
difference in prices and to select the best option for you (if you are
a home user ADSL is better for you, small and medium businesses with
high use of B2B internet services will prefer SDSL).
For additional references plese visit the following pages:
"Common sdsl questions" from Advent Broadband SDSL-ADSL:
http://www.adventit.co.uk/broadband/faq-sdsl.htm
"Comparison of Symmetric and Asymmetric DSL (ADSL and SDSL) Internet access":
http://www.broadbandinfo.com/internet-connections-101/types-of-internet-connections/dsl/adsl-vs-sdsl.html
"Advantages and Disadvantages of Symmetric Service DSL":
http://www.broadbandinfo.com/internet-connections-101/types-of-internet-connections/dsl/symmetric.html
"SDSL FAQ's":
http://www.twang.net/products/connectivity_sdsl_faq.asp
See also the "Business DSL from Business DSL Service" page:
http://www.business-dsl-service.com/index.php
- Search strategy -
I used the following keywords at Google.com:
sdsl benefits
sdsl adsl
sdsl adsl comparison
sdsl adsl comparison prices
Please do not consider this answer ended until you feel satisfied with
it. You can use the clarification feature if you find this answer
incomplete or unclear. I will gladly respond your requests for an
answer clarification.
Regards,
livioflores-ga |
Request for Answer Clarification by
esarkissian-ga
on
08 Nov 2005 09:43 PST
Thanks livioflores, some clarifications please:
"At same connection rate the SDSL offers the same rate for upload and
download. You asked who cares? I can tell you that business people
cares. The SDSL service is intended for businesses or people who use
the Internet connection for sending e-mails, videoconferencing,
netmeeting, web hosting, and business to business applications. That
is applications where the use of upload direction is as much important
as download is."
Yes but even at equal upload/download, the upload speed is still 384
Kbps - which is slower than the 768 upload of the ADSL. So I still
don't understand why equal upload/download is such a big deal,
especially if it's slower than the ADSL.
"SDSL is slower than ADSL but usually marketed with Service Level
Agreement (SLA) such as the network will be guaranteed up for 99.5%,
and there will be a
24-hour response time for every problem."
Is that not the case for ADSL? My ISP is claiming 99% uptime, the same for SDSL.
"(if you are a home user ADSL is better for you, small and medium
businesses with high use of B2B internet services will prefer SDSL)."
We're a small business of 7 employees. We rely heavily on the
Internet/email, so uptime is very important to us. Our website and
mail servers are hosted offsite by a 3rd party, so I don't think a
static IP is important. What would you recommend for our purposes?
Thanks,
Ed
|
Clarification of Answer by
livioflores-ga
on
08 Nov 2005 14:15 PST
HI!!
To a proper answer to your request I need to know what are the
additional services offered with the SDSL service. But after a first
look the ADSL option appears to be the smartest choice. If it is the
same company offering both services, SDSL is considered an upgrade,
ask about the possibility to contract ADSL and then, after some month
of testing, upgrade to SDSL.
If you can give me a link where I can see a description of both
services I can tell you if the SDSL worth the difference, but again
seeing your business description, the offered ADSL service could fit
your needs perfectly.
Regards,
livioflores-ga
|
Clarification of Answer by
livioflores-ga
on
08 Nov 2005 22:19 PST
Hi again!!
Dedicated Loop ADSL is the better option for you in my opinion. SDSL
services is intended for companies more high sized than yours, I think
that you will take all from it.
If you choose the Dedicated Loop ADSL a new line will be installed for
the 3.0/768 rate service. You will have a lot more download rate and,
for sure, at least the same rate, but nearly the double, for uploads.
Considering only data transfer rates, in your situation, the ADSL
option is better and cheaper; so it is the smartest choice. Check
again the additional services offered with SDSL and if you will not
miss them go ahead with ADSL.
Take into account that you will need to buy or rent a new ADSL modem.
According with a further research, Dedicated Loop ADSL or Dry ADSL is
relatively a new trend in DSL services and they are commonly featured
good enough for your needs, see the following pages for references:
"Covad Launches Dedicated-Loop ADSL for Consumers and Small Businesses Nationwide":
http://www.tmcnet.com/usubmit/2004/Jul/1054283.htm
"Net Vista - Dedicated Loop ADSL":
http://www.netvista.net/services/dsl/dl_adsl.asp
"Lightning Bolt DSL, Business Services":
See under Dry Line.
http://lbdsl.com/business-services.html#ADSL line share
Want to see a Service Agreement:
"Covad TeleSoho - DEDICATED LOOP DSL SERVICE AGREEMENT":
http://www.lmi.net/forms/CovadDSL-ded.loop.SoHo.pdf
And a "Service Level Agreement":
http://lbdsl.com/sla-v4.pdf
Hope this helps.
Regards,
livioflores-ga
|
