FTTC and Skype

I have been on FTTC for just over a week, and my provider has an excellent bandwidth usage page that I can visit.

Before going to FTTC, My usage was always relatively small (3.4mbs connection). Now it is vastly higher. In part I have to admit this is me trying out a few new things.

The usage page shows traffic every ten minutes and there are lots of occasions when I know that there should have been very little traffic and there has been lots.

Today I have signed out of Skype and killed the process and the usage is minimal again.

Has anyone else noticed this behaviour? If my suspicion is right then it would use several GB of my peak time monthly usage allowance.

I probably ought to add I have used Skype for ages and think it is a great product.

Yes, Skype gobbles your bandwidth.

I see the same and stay signed out and only open Skype when I have a call scheduled - I don't use it for normal calls just international conference calls.

Read http://en.wikipedia.org/wiki/Skype_protocol

Suspect you may have because of your high bandwidth become a sharing node, particularly if your NAT is very open or non-existent.

In reply to a post by MrSaffron:

Read http://en.wikipedia.org/wiki/Skype_protocol

Suspect you may have because of your high bandwidth become a sharing node, particularly if your NAT is very open or non-existent.

But why? It would normally require a complete link and pushing traffic in and out on the same connection serves no purpose.

I have seen problems in the past where our transatlantic connections were having bandwidth "stolen" by Skype - a continuous stream of 10s of Mbps - until we banned Skype in the company and insisted on it being removed from all PCs.

http://yarwell.blogspot.com/2006/11/skype-stole-my-p...

its a P2P architecture I don't know if the actual voice or video flows through nodes but certainly the control does.

maybe I should packet sniff Skype chat

Thank you for your replies.

My router does NAT and connected to the router is my Linux box Firewall, to which I connect, so NAT on that as well. Confess the firewall was set up by my nephew and is beyond me, https://www.grc.com says I am in true stealth mode, but If Skpe is advertising itself from within my system I appreciate that will make no difference.

I did read lots of things about NAT stops you becoming a supernode, but they were all quite old messages (2005-2009) so wondered if Skype had modified their software.

I did read lots of things about NAT stops you becoming a supernode

I don't think they were true even then.

Skype probably uses uPNP (http://en.wikipedia.org/wiki/Universal_Plug_and_Play) on the router to open and close ports as required.

You can usually disable uPNP on the router's web interface, although doing so may make some applications and games play up.