Broadband

Introduction to Broadband

DSL = Digital Subscriber Line

ADSL (Asymmetrical DSL) is limited to 18 000 feet (5.46 km or 3.4 miles)
with ADSL, the upload speed < download speed
upstream limit 640 kb/s (64 -640 kb/s usually)
downstream limit 8 Mb/s (1.5 Mb/s usually)

DSL operates on (or shares) the same wires as Plain Old Telephone Service "POTS" (which was
designed for frequencies below 4 kHz), but DSL operates at high frequencies (up to several MHz).

ADSL upstream bandwidth starts at 25.875 kHz and ends at 138 kHz.
ADSL downstream bandwidth starts at 25.875 kHz and ends at 1.104 MHz.

the provider has a DSLAM (DLS Access Multiplier)
the customer has a DSL Transceiver/ATU-R (DSL Modem)

an example of a DSLAM is the ?
an example of a DSL modem is the ?

other flavors of DSL include:
VDSL (Very high speed DSL) works only at short distances
SDSL (Symmetric DSL) upload speed = download speed
SDSL operates on a dedicated pair of wires
RADSL rate-adaptive DSL, adjusts to line quality
LDSL (Long-reach DSL)/ READSL (Range extended ADSL)

advantages: works over ordinary copper twisted-pair telephone lines
advantages: competing vendors keep prices lower

disadvantages: you must be within 18 000 feet (3.4 miles) of a phone company switch room

Cable Broadband
downstream limit 3.0 Mb/s (2.25 Mb/s usually)
upstream limit 256 kb/s (?? usually)

the provider has a CMTS (Cable Modem Termination System)
the customer has a CM (Cable Modem)

a typical CMTS serves between 500 and 2000 CMs

an example of a CMTS is the ?
an example of a Cable Modem is the Motorola SURFboard Cable Modem

advantages: works over existing coax cable TV wire, at the same time
advantages: upstream data is sent to the CMTS only (each CM is given an interval of time to transmit)

disadvantages: downstream data physically flows to all connected users, could be easily intercepted
disadvantages: as more customers are added to your channel, performance will degrade
disadvantages: cable companies don't (yet) have any competition

Something else to consider when using Comcast Cable:
when the RIAA issued subpoenas to ISPs, to reveal the identities of
their users who the RIAA suspected of illegally downloading music files,
Comcast ratted out their customers without hesitation or objection.

Verizon Communications and Pacific Bell Internet Services challenged
the RIAA subpoena. Charter Communications was the first cable operator
to challenge the subpoena.
Verizon was compelled by the U.S. District Court in Washington D.C. to
give up its customers names, and appealed the decision.

* * * * *

Highest data rates I've observed on a 1.5 Mbps / 384 kbps Verizon ADSL line:

download speed:
191 kB/s [sonicstudios.com]
175.8 kB/s [mozilla.org]
75 kB/s [BitTorrent]

upload speed:
47 kB/s [using BitTorrent]

186 KB/Sec from Microsoft, consistently (large downloads)

According to the CNET Bandwidth Meter test, my DSL connection is capable of 586.1 kbps.

According to DSLreports speed test:
Your download speed : 1521613 bps, or 1485 kbps,
which equals a 185.7 KB/s transfer rate.
Your upload speed : 376837 bps, or 368 kbps

1485/368 is pretty close to Verizon's advertised DSL speed of 1536/384.

* * * * *

Previously using an external 56k modem, I saw a maximum of about
9 kb/s for downloading and 9 kb/s for uploading via BitTorrent.

On my 10Mbps 10BaseT ethernet network, I see a maximum data rate:
* betweeen 2 PCs, with 1 hub between them... 1.07 Mb/s
* between 2 PCs, with 2 hubs between them... 16.9 kB/s
(excessive collisions)

SNiP account expires Nov. 1, 2005

* * * * *

February 8, 2006
before requesting upgraded DSL service:

via CNET test: 1083.4 Kbps
via www.pcpitstop.com/internet/Bandwidth.asp:  1062 Kbps, 1053 Kbps
via (Media, PA) www.wugnet.com/myspeed/speedtest.asp: 1.37 Mbps, 1.48 Mbps, 1.38 Mbps [download]
via (Media, PA) www.wugnet.com/myspeed/speedtest.asp: 374 Kbps, 373 Kbps, 375 Kbps [upload]

Verizon Business (static IP) DSL
results of bandwidth speed tests

service was originally provisioned as 1.5 Mb/s download - 384 Kb/s upload

date               download speed upload speed
2005.05.20          1485 Kb/s          368 Kb/s
2006.02.08          1403 Kb/s          374 Kb/s
2008.01.29          1478 Kb/s          361 Kb/s
2008.01.29          1471 Kb/s          357 Kb/s

during temporary testing with a Verizon technician
date               download speed upload speed
2008.01.29          1454 Kb/s          605 Kb/s

service was “upgraded” (reconfigured) as 3 Mb/s download - 768 Kb/s upload
date               download speed upload speed
2008.01.30           2310 Kb/s          719 Kb/s
2008.01.30           2542 Kb/s          707 Kb/s
2008.12.15           2520 Kb/s          739 Kb/s
2008.12.15           2540 Kb/s          722 Kb/s

Verizon Business Tech Support 888-649-9500

switching from 3 MB/ 768 Kb DSL to 20 MB / 5 MB FiOS from Verizon

previous monthly cost:
Static IP DSL $79.99   [12/19/2008>1/18/2009]
Comcast Cable TV “basic & expanded” $59.13   [1/1/2009>1/31/2009]
610-892-3878 dial tone $38.46   [12/25/2008>1/24/2009]

610-892-8698 dial tone $23.88   [12/25/2008>1/24/2009]

new montly cost:
Static IP FiOS $99.99

FTP speed

internal transfer:
ftp: 64353116 bytes received in 5.53Seconds 11634.99Kbytes/sec. (11.4Mbytes/sec)

external transfer:

Bandwidth Chart

          56 KB modem @ 16%                     9 KB/Sec            0.01 MB/Sec

   1.5 MB/Sec (DSL) @ 96%                1480 KB/Sec           1.45 MB/Sec

Installing software from a CD-R to a hard disk       1946 KB/Sec            1.9 MB/Sec

Burning a CD-R at 24x speed                4198 KB/Sec             4.1 MB/Sec

   3.0 MB/Sec (DSL) @ 83%                2540 KB/Sec           2.48 MB/Sec