[145655] in North American Network Operators' Group
Re: How Skype uses the network [was: News item: Blackberry services
daemon@ATHENA.MIT.EDU (Cameron Byrne)
Fri Oct 14 15:19:17 2011
In-Reply-To: <AB07788A-A060-48F0-BC27-9A0F69DB4921@ianai.net>
Date: Fri, 14 Oct 2011 12:17:41 -0700
From: Cameron Byrne <cb.list6@gmail.com>
To: "Patrick W. Gilmore" <patrick@ianai.net>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Fri, Oct 14, 2011 at 12:11 PM, Patrick W. Gilmore <patrick@ianai.net> wr=
ote:
> On Oct 13, 2011, at 7:26 PM, Matthew Kaufman wrote:
>> On 10/13/11 3:30 PM, Patrick W. Gilmore wrote:
>>> In fact, Skype, just as a for instance, is worse on hotel wifi as launc=
hing the app on a laptop makes you a middle node for some conversations.
>>
>> Per the Skype IT administrator guide, a Skype node will not become a sup=
ernode unless it has a public IP address and meets the memory, bandwidth, a=
nd uptime requirements. It will not become a relay node unless it has a pub=
lic IP address and is directly reachable from the Internet.
>>
>> It is very unlikely that launching the Skype app on a laptop on hotel wi=
-fi would meet these requirements.
>
> In the last 5 seconds, without touching Skype or having any active voice =
or chat sessions open, my computer has had communication with 14 IP address=
es. =A0Here is a sample of some:
>
> =A0 =A0 =A0 =A0TiggerAir-i7-2:~ patrick$ host 94.193.99.152
> =A0 =A0 =A0 =A0152.99.193.94.in-addr.arpa domain name pointer 94-193-99-1=
52.zone7.bethere.co.uk.
> =A0 =A0 =A0 =A0TiggerAir-i7-2:~ patrick$ host 78.90.137.244
> =A0 =A0 =A0 =A0Host 244.137.90.78.in-addr.arpa. not found: 3(NXDOMAIN)
> =A0 =A0 =A0 =A0TiggerAir-i7-2:~ patrick$ host 175.129.63.150
> =A0 =A0 =A0 =A0150.63.129.175.in-addr.arpa domain name pointer KD17512906=
3150.ppp-bb.dion.ne.jp.
> =A0 =A0 =A0 =A0TiggerAir-i7-2:~ patrick$ host 218.190.29.244
> =A0 =A0 =A0 =A0Host 244.29.190.218.in-addr.arpa. not found: 3(NXDOMAIN)
> =A0 =A0 =A0 =A0TiggerAir-i7-2:~ patrick$ host 128.2.238.215
> =A0 =A0 =A0 =A0215.238.2.128.in-addr.arpa domain name pointer ETC-NALZAYE=
R.ETC.CMU.EDU.
> =A0 =A0 =A0 =A0TiggerAir-i7-2:~ patrick$ host 212.187.172.66
> =A0 =A0 =A0 =A0Host 66.172.187.212.in-addr.arpa. not found: 3(NXDOMAIN)
>
> Those do not look like Skype servers. =A0I guess it is possible everyone =
in my contact list is somehow pinging me, but that seems a little bit silly=
.
>
> My IP address is 172.30.19.19, hopefully I do not have to explain that th=
is is not a "public IP address". =A0I have been online a few minutes, so un=
less their uptime requirements are about the same as a regular phone call, =
it is too short. =A0I will admit, I have plenty of bandwidth available, tho=
ugh.
>
And, then there is the increasing prevalence of squat space which may
muddy common heuristics.
> In short, while they can claim my laptop is not being used as a supernode=
or relay, Skype is still randomly talking to a slew of IP addresses. =A0An=
yone know what Skype is doing?
>
>
>>> Does Skype on $HANDHELD have the same property?
>> Not as far as I know, for the obvious reason that handheld devices have =
network connections that are suboptimal for this.
>
> The above happens to my laptop when I am on 3G / EDGE, even when I have a=
10-net address. =A0In fact, one of the first things I do on 3G is kill Sky=
pe because it noticeably increases my network performance.
>
> I haven't checked on my iPhone 'cause I don't have things like tcpdump & =
little snitch.
>
> --
> TTFN,
> patrick
>
>
>
