Skype or not?

Skype is free, but... Read this article:

http://paul.kedrosky.com/archives/002372.html

Regards.

On Sat, 23 Sep 2006 00:51:28 +0200, "SBS" <no.spam@grazie.da.me>
wrote:

>Skype is free, but... Read this article:
>
>http://paul.kedrosky.com/archives/002372.html
With reference to the article it could well have been Skype. It can be
responsible for more bandwidth eating than for just the call you are
on.

Remove 'no_spam_' from email address.
Skype Free Zone!!

Brian A wrote:
> On Sat, 23 Sep 2006 00:51:28 +0200, "SBS" <no.spam@grazie.da.me>
> wrote:
>
>> Skype is free, but... Read this article:
>>
>> http://paul.kedrosky.com/archives/002372.html
> With reference to the article it could well have been Skype. It can be
> responsible for more bandwidth eating than for just the call you are
> on.

"It would certainly be puzzling, because if Skype was so poorly architected
as to network-misbehave like this then you would think that all sorts of
people would be reporting the same problem."

They certainly would. Where are they all? I guess it's not Skype after all
:-)

--
Carl Waring
DigiGuide: http://getdigiguide.com/?p=1&r=1495
DGLite: http://getdigiguide.com/?p=4&r=1495 - FREE!!!

Rich (richdotward@gmail.com) ha scritto:

:: Whats the big deal. Skype has always worked like this!
::
:: If you have plenty of bandwidth then its used to help other
:: people out.

Who grant me that my bandwidth (I have paid) has not been
used by skype to make possible any charged calls?

Brian A (no_spam_bca1000@hotmail.com) ha scritto:

::: http://paul.kedrosky.com/archives/002372.html

:: With reference to the article it could well have been Skype. It can be
:: responsible for more bandwidth eating than for just the call you are
:: on.

It does, I am sure!

Carl Waring (carl.waring@REDyonder.co.uk) ha scritto:

:: "It would certainly be puzzling, because if Skype was so
:: poorly architected as to network-misbehave like this then
:: you would think that all sorts of people would be reporting
:: the same problem."
::
:: They certainly would. Where are they all? I guess it's not
:: Skype after all :-)

You are wrong :-)

SBS wrote:
> Rich (richdotward@gmail.com) ha scritto:
>
> :: Whats the big deal. Skype has always worked like this!
> ::
> :: If you have plenty of bandwidth then its used to help other
> :: people out.
>
> Who grant me that my bandwidth (I have paid) has not been
> used by skype to make possible any charged calls?
>
>

It's quite easy for the average home user to stop their PC
becoming a supernode. It should be possible for firewalled
businesses to stop it as well.

SBS wrote:
> Carl Waring (carl.waring@REDyonder.co.uk) ha scritto:
>
>>> "It would certainly be puzzling, because if Skype was so
>>> poorly architected as to network-misbehave like this then
>>> you would think that all sorts of people would be reporting
>>> the same problem."
>>>
>>> They certainly would. Where are they all? I guess it's not
>>> Skype after all :-)
>
> You are wrong :-)

Prove it then :-D

--
Carl Waring
DigiGuide: http://getdigiguide.com/?p=1&r=1495
DGLite: http://getdigiguide.com/?p=4&r=1495 - FREE!!!

Carl Waring (carl.waring@REDyonder.co.uk) ha scritto:

::::: I guess it's not Skype after all :-)

::: You are wrong :-)

:: Prove it then :-D

The article: http://paul.kedrosky.com/archives/002372.html
proves it.

JW (jw@privacy.net) ha scritto:

:: It's quite easy for the average home user to stop their PC
:: becoming a supernode.

How can I do it?

"SBS" <no.spam@grazie.da.me> wrote in message
news:4516c7b7$0$17455$4fafbaef@reader4.news.tin.it
> JW (jw@privacy.net) ha scritto:
>
> > > It's quite easy for the average home user to stop
> > > their PC becoming a supernode.
>
> How can I do it?

Don't run Skype.

Ivor

On Sun, 24 Sep 2006 21:35:35 +0100, "Ivor Jones"
<ivor@despammed.invalid> wrote:

>"SBS" <no.spam@grazie.da.me> wrote in message
>news:4516c7b7$0$17455$4fafbaef@reader4.news.tin.i t
>> JW (jw@privacy.net) ha scritto:
>>
>> > > It's quite easy for the average home user to stop
>> > > their PC becoming a supernode.
>>
>> How can I do it?
>
>Don't run Skype.
>
>Ivor
Ha ha ...very good Ivor :-)


Remove 'no_spam_' from email address.
Skype Free Zone!!

SBS wrote:
> Carl Waring (carl.waring@REDyonder.co.uk) ha scritto:
>
>>>>>> I guess it's not Skype after all :-)
>
>>>> You are wrong :-)
>
>>> Prove it then :-D
>
> The article: http://paul.kedrosky.com/archives/002372.html
> proves it.

ONE article on the whole of the internet? Yeah. Okay :-D

--
Carl Waring
DigiGuide: http://getdigiguide.com/?p=1&r=1495
DGLite: http://getdigiguide.com/?p=4&r=1495 - FREE!!!

On Mon, 25 Sep 2006 08:51:07 GMT, "Carl Waring"
<carl.waring@REDyonder.co.uk> wrote:

>SBS wrote:
>> Carl Waring (carl.waring@REDyonder.co.uk) ha scritto:
>>
>>>>>>> I guess it's not Skype after all :-)
>>
>>>>> You are wrong :-)
>>
>>>> Prove it then :-D
>>
>> The article: http://paul.kedrosky.com/archives/002372.html
>> proves it.
>
>ONE article on the whole of the internet? Yeah. Okay :-D
There are in fact many articles on the Net about the bandwidth used by
Skype. You only need to google to see that.
Here is a discussion on the Skype forum which may prove of interest
and of use.
http://tinyurl.com/m3db6
Remove 'no_spam_' from email address.
Skype Free Zone!!

On Sun, 24 Sep 2006 22:04:06 GMT, Brian A
<no_spam_bca1000@hotmail.com> wrote:

>On Sun, 24 Sep 2006 21:35:35 +0100, "Ivor Jones"
><ivor@despammed.invalid> wrote:
>
>>"SBS" <no.spam@grazie.da.me> wrote in message
>>news:4516c7b7$0$17455$4fafbaef@reader4.news.tin. it
>>> JW (jw@privacy.net) ha scritto:
>>>
>>> > > It's quite easy for the average home user to stop
>>> > > their PC becoming a supernode.
>>>
>>> How can I do it?
>>
>>Don't run Skype.
>>
>>Ivor
>Ha ha ...very good Ivor :-)
>
>
>Remove 'no_spam_' from email address.
>Skype Free Zone!!
Here is a technical article on the workings of Skype by:-

Salman A. Baset and Henning Schulzrinne
Department of Computer Science
Columbia University, New York NY 10027
{salman,hgs}@cs.columbia.edu
September 15, 2004

http://tinyurl.com/5hal4

Extracts:- (Note: SC=Skype Client, SN=Super Node)

"Any node with a public IP address having
sufficient CPU, memory, and network bandwidth is a candidate to
become a super node."


"Unlike its file sharing counter part KaZaa, a SC cannot prevent
itself from becoming a super node."


"We observed that a SC must establish a TCP connection with a
SN in order to connect to the Skype network. If it cannot connect
to a super node, it will report a login failure."

Most firewalls are configured to allow outgoing TCP traffic to
port 80 (HTTP port) and port 443 (HTTPS port). A SC behind a
firewall, which blocks UDP traffic and permits selective TCP
traffic, takes advantage of this fact. At login, it establishes a TCP
connection with another Skype node with a public IP address and
port 80 or port 443."

END QUOTES
I would glean from this that a Skype Client CAN become a super node,
under appropriate conditions, and, as such, exchange much higher
levels of data than expected. Also, that some clients HAVE to be
supernodes of the system would not work.

So, the apparent increase in quality of sound (though not consistent)
is at the expense of the super node clients.



Remove 'no_spam_' from email address.
Skype Free Zone!!

SBS wrote:
> JW (jw@privacy.net) ha scritto:
>
> :: It's quite easy for the average home user to stop their PC
> :: becoming a supernode.
>
> How can I do it?
>
>

Put your PC into standby or off when not in use. This is
not of course possible if you want to receive incoming calls
all the time, but then if you want that, you'd probably not
want to use Skype.

Alternatively, use a router.

Brian A wrote:
<<snip quotes>>
> I would glean from this that a Skype Client CAN become a super node,
> under appropriate conditions, and, as such, exchange much higher
> levels of data than expected. Also, that some clients HAVE to be
> supernodes of the system would not work.

Indeed, but this is not to say that ANY Client can become a
super node.

>
> So, the apparent increase in quality of sound (though not consistent)
> is at the expense of the super node clients.
>

I'm sure you didn't mean to imply that the voice traffic is
routed via the super nodes.

On Wed, 04 Oct 2006 11:26:18 +0100, JW <jw@privacy.net> wrote:
>Brian A wrote:
><<snip quotes>>
>> So, the apparent increase in quality of sound (though not consistent)
>> is at the expense of the super node clients.
>
>I'm sure you didn't mean to imply that the voice traffic is
>routed via the super nodes.

It could well be (it's encrypted though, if you believe Skype), it's the
only way to route traffic between two users who are both behind NAT setups
(e.g. router users) without one of them doing a port-forward.

--
-- Michael "Soruk" McConnell
Eridani Star System

MailStripper - http://www.MailStripper.eu/ - SMTP spam filter
Mail Me Anywhere - http://www.MailMeAnywhere.com/ - Mobile email

Soruk <soruk@bitbucket.eridani.co.uk> wrote:
> It could well be (it's encrypted though, if you believe Skype), it's the
> only way to route traffic between two users who are both behind NAT setups
> (e.g. router users) without one of them doing a port-forward.

There are certain circumstances when it /is/ possible for two users,
both behind NAT devices, to communicate directly with each other. This
is well-understood P2P technology.

Consider two users, A and B, and a supernode C. A can talk to C. B can
talk to C. Neither A nor B can receive new inbound sessions as they
are both behind NAT firewalls. However, either A or B can initiate new
outbound sessions, courtesy their NAT devices. All traffic in this
scenario is UDP based.

1. A initiates session to C
2. B initiates session to C

A wants to talk directly to B

3. A says to C, "please tell B to talk to me"
4. C passes this message on, using the session started by B in #2
5. A starts talking to B

At this stage, packets from A are discarded by B's NAT firewall

6 B starts talking to A

Now, since A's NAT firewall thinks it is already talking to B, it
lets the packets back in. Further, since B is already talking to A,
A's packets to B are also let in by B's firewall

7. A and B are now talking directly to each other, and C is no longer
required

Chris

On Tue, 10 Oct 2006 21:24:29 +0100, Chris Davies <chris-usenet@roaima.co.uk> wrote:
>Soruk <soruk@bitbucket.eridani.co.uk> wrote:
>> It could well be (it's encrypted though, if you believe Skype), it's the
>> only way to route traffic between two users who are both behind NAT setups
>> (e.g. router users) without one of them doing a port-forward.
>
>There are certain circumstances when it /is/ possible for two users,
>both behind NAT devices, to communicate directly with each other. This
>is well-understood P2P technology.
>
>Consider two users, A and B, and a supernode C. A can talk to C. B can
>talk to C. Neither A nor B can receive new inbound sessions as they
>are both behind NAT firewalls. However, either A or B can initiate new
>outbound sessions, courtesy their NAT devices. All traffic in this
>scenario is UDP based.
>
>1. A initiates session to C
>2. B initiates session to C
>
>A wants to talk directly to B
>
>3. A says to C, "please tell B to talk to me"
>4. C passes this message on, using the session started by B in #2
>5. A starts talking to B
>
>At this stage, packets from A are discarded by B's NAT firewall
>
>6 B starts talking to A
>
>Now, since A's NAT firewall thinks it is already talking to B, it
>lets the packets back in. Further, since B is already talking to A,
>A's packets to B are also let in by B's firewall
>
>7. A and B are now talking directly to each other, and C is no longer
>required

Thank you for that explanation. I was trying to imagine how it could work
without any losses - but I see at stage 5 of your illustration there is
indeed some loss (though, being part of the design, the lost packets
should hopefully contain nothing important).

--
-- Michael "Soruk" McConnell
Eridani Star System

MailStripper - http://www.MailStripper.eu/ - SMTP spam filter
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On Tue, 10 Oct 2006 21:24:29 +0100, Chris Davies <chris-usenet@roaima.co.uk> wrote:
>5. A starts talking to B
>At this stage, packets from A are discarded by B's NAT firewall
>6. B starts talking to A

Soruk <soruk@bitbucket.eridani.co.uk> wrote:
> Thank you for that explanation. I was trying to imagine how it could work
> without any losses - but I see at stage 5 of your illustration there is
> indeed some loss (though, being part of the design, the lost packets
> should hopefully contain nothing important).

That's correct.

Essentially A keeps saying "Hello B, are you there (yet)?" until it gets a
message from B (via C) to say it's given up trying or a timeout's reached.

Chris