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Re: ADSL Test Report was: ADSL Installation Update
Title: dslreports.com - About Speed
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Here is some info that may
be of use to you (from ADSLguide.org.uk)
What is NAT? How does it operate over
ADSL?
| What is
NAT? |
| NAT is an
acronym for Network Address Translation. It operates as a solution
to having multiple, global IP addresses. If you intend to connect
your current LAN to The Internet, it is likely you will use a form
of NAT so that each computer does not require a global unique IP
address, but instead can use private addressing in the ranges:
10.0.0.0 -> 10.254.254.254
172.16.0.0 ->
172.31.254.254
196.168.0.0 -> 192.168.254.254
All
traffic for an The Internet goes through one external host--Usually
a router. |
| How does
NAT work? |
| NAT is
often built into routers. It receives each packet from the internal
private network and modifies the IP header to match the global IP
address of the router, before it is transmitted out into The
Internet. The router stores the internal IP address, destination IP
address and port number in a routing table so when a request is
returned on the same port, the NAT can match the internal IP address
that originated the request, and then modify the IP header to match
that of the internal address. |
| So NAT is
a good thing? |
| Generally, yes. NAT saves on IP allocation. You
can use an IP address from one of those in the ranges stated above
for all the internal hosts on your LAN, but still connect to The
Internet using NAT. Each IP address costs money, so NAT will help
reduce costs. It should also help keep IPv4 address available until
we are converted to IPv6. |
| Why do I
hear complaints about NAT? |
| You may
hear a lot of complaints from people complaining about NAT
especially on the BT ADSL trials. These people however are
incorrectly referring to NAT when they should be speaking of port
forwarding. |
| What is
port forwarding? |
| Port
forwarding is often a feature built into routers which perform NAT.
It allows the router to forward any unrequested traffic generated
from The Internet side of the router to a specified internal host.
For example, you may run an Apache Web Server on port 80 of machine
10.0.0.5, and may want this server accessable from The Internet. A
rule can be added to the router so that any requests, that are not
replies to those from the local network, on port 80 are forwarded to
IP address 10.0.0.5. You can assign a global rule so that all ports
are forwarded to one internal server, or you can specify different
IP addresses for different ports. So if you have a different IP
address for your FTP server, you can specify this rule in the
routers configuration also. |
| Why do I
hear complaints about port forwarding? |
| Those
people on current ADSL trials from BT are connected via a NAT
enabled router. However, the router has not been configured to allow
port forwarding. Although the feature is available on the router, BT
have said that the service is not to be enabled. There is
speculation as to whether this will also be the case in the final
release of the service, and this choice may be up to each ISP to
choose how they want it configured. |
| What does
it mean if port forwarding is not enabled? |
If it is
not enabled, you will not be able to host any services on your ADSL
connection. You may be thinking "So what?". You may think that this
does not affect a large proportion of consumers but you are wrong.
There are many applications that require port forwarding enabled to
function properly, such as:
- DCC send & IDENTD functions of IRC
- Netmeeting will only allow you to hear the other person. They
can't hear you.
- ICQ fails on some functions due to it thinking you are behind
a firewall
- Direct play games don't work
The list is long. |
| So NO
port forwarding is totally a bad thing? |
| Not
totally. The router does not forward requests anywhere, it will mean
that you network is more secure against attacks on the services
running against them. It should not be seen as a firewall solution,
but is more secure than having port forwarding enabled. Note:
This does not mean your network *IS* secure. It is still possible to
make outbound connections by malicious
programs. | |
----- Original Message -----
Sent: Monday, October 16, 2000 4:29
PM
Subject: RE: [ukha_d] ADSL Test Report
was: ADSL Installation Update
BT do seem to have
disabled
the ability to run a server over OpenWorld. Mark McCall tried to
access
my machine earlier today without success. I'm hoping they will be
pressured into relaxing some of their blocking as more people come on-line
and
start hassling them.
Graham
WOW!! thats fast!
Just for anyone who's thinking of getting a
Blueyonder cable modem, here's my result for the megapath
server:
Your download speed :
408940 bps, or 408 kbps.
Browsers would
show : about a 49.9 k/sec transfer rate.
Your upload
speed : 89887 bps, or 89
kbps.
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The ADSL result was very impressive! but
I heard you can't run servers on the BT package?
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----- Original Message -----
Sent: Monday, October 16, 2000 4:10
PM
Subject: RE: [ukha_d] ADSL Test
Report was: ADSL Installation Update
East coast was even
faster
Your download speed : 711742
bps, or 711 kbps.
Browsers would
show : about a 86.8 k/sec transfer rate.
Your upload speed :
2485501 bps, or 2485 kbps.
Your
upload speed is much faster than down.. have you tweaked?
:-)
Keith
I've just run the test
suggested by Neil F, here are the results:
Graham
;) Speed
Interpretation |
10/16 server load: »»»»» |
|
Navigation
help
Newsletter
glossary:
|
(table key)
| kbps |
65 |
129 |
193 |
257 |
321 |
385 |
449 |
513 |
577 |
| k/sec |
8 |
16 |
24 |
32 |
40 |
48 |
56 |
64 |
72 |
| time |
21.3h |
10.6h |
7.1h |
5.3h |
4.2h |
3.5h |
3h |
2.6h |
2.3h |
| |
Some useful
comparisons |
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telephone quality
voice | |
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33.6k modem download
speed | |
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typical 56k modem download
speed | |
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single channel
ISDN | |
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dual
channel ISDN | |
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IDSL | |
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150k
Video Stream | |
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Fastest multiplayer
game | |
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192k
'near CD quality' MP3 | |
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300k
Video Stream | |
| DOWN |
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| UP |
| |
Cable/DSL Performance Archive Project
Help us
collect accurate speed statistics:
My zip code is:
(just so we know
what city you are in)
My provider is: (or .. name of ISP):
My line
speed should be: down / up kbps
(eg 640 / 90 or 608 / 128 or 3000 /
300)
The time here is now: :30 (24 hour
clock)
I've already tweaked
my PC: (for higher
download speed)
Privacy
concerns? this information is used to create per
provider/region speed statistics, thats
it! | | How
good is this? Compare against
others in your
area
The last few minutes lines tested at (kbps
down/kbps up):
1211/300
(wc)
1154/332 (ec)
1927/346 (ec)
239/580
(wc)
346/796 (wc)
1261/103 (ec)
225/247
(wc)
702/121 (wc)
371/123 (wc)
349/610
(ec)
1825/373 (wc)
482/107 (wc)
|
346/370
(wc)
43/28 (wc)
381/134 (wc)
239/603 (wc)
165/85
(wc)
155/110 (ec)
277/292 (wc)
312/108
(wc)
396/226 (wc)
656/642 (ec)
648/136
(wc)
497/72 (wc)
|
1041/215
(wc)
173/103 (wc)
460/709 (wc)
3163/934
(wc)
681/121 (ec)
1422/692 (wc)
1273/335
(wc)
1111/435 (ec)
53/105 (wc)
912/578
(ec)
34/382 (wc)
270/122 (wc)
|
509/67
(wc)
42/394 (wc)
640/317 (wc)
1101/108
(wc)
705/137 (wc)
508/70 (wc)
500/47
(ec)
3221/748 (wc)
364/54 (ec)
3095/780
(wc)
2876/247 (wc)
138/97 (wc)
|
640/104
(wc)
188/50
(wc)
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