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ADSL (6 Mbps / 768 Kbps )

D-Link DIR-625 Router

Hi Guys,

Whenever one of my family members uses skype video to chat with friends it interferes with other internet tasks... particularly:

  • SIP / Asterisk Voip Phone calls (conversations are broken up)
  • GoToMeeting screen sharing connections get interrupted
  • General downloads

I'd like to adjust my QOS rules to reduce the amount of bandwidth Skype consumes but I'm not sure what port its using for outbound communication. Any ideas? Or perhaps there's a better way to handle this? I don't see any throttling options in the Skype config itself.

Any/all suggestions are welcome.

share|improve this question
I'd switch to Google Talk video. It uses far less bandwidth than Skype. Failing that, you could probably shape your traffic at the router level for whichever port / protocol Skype uses as the highest priority. – user3463 Dec 1 '09 at 7:51
up vote 1 down vote accepted

As Randolph Potter commented, you can shape at the router level, or you can use something like netlimiter to shape traffic on the particular machine.

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Worth nothing that the free version of netlimiter does not allow shaping, you need to buy the full version. – John T Dec 3 '09 at 20:10
Whats wrong with buying something the User needs? – Jakub Dec 3 '09 at 20:16
i think, John T. wanted to say 'worth noting'. and of course there is nothing wrong with buying a program that is worth using. some people write code for a living :) oh, and +1 – Molly7244 Dec 3 '09 at 20:52
Thanks guys. I'm going to build a pfsense box and try more traffic shaping that way. – Mike B Dec 4 '09 at 0:51
Just an update: the pfsense box has done wonders... still need to test more (and bandwidth has been more limited) but I don't have to worry about it monopolizing all of my network's bandwidth. – Mike B Dec 9 '09 at 19:38

This was one of the posts that I came across while in vain trying to control Skype's bandwidth on Linux.

Finally I got to a way to do that and have explained it here (the post has moved). See if it works for you.

Here is the text from that post:

The Solution

After hours of searching and hair pulling action, I came up with an addition to Solution 2 – use iptables to block access to skype. Now, iptables doesn't really have per application rules (like what people are used to from Windows Firewall etc) but it can filter on user/group. Using this, I did the following-

  • Install and start squid
  • Create a group called nonet
  • Use the following iptables rules to block all communication for the group nonet, but still allow access to where squid runs (order is important)-
sudo iptables -A OUTPUT -p tcp -s –dport 3128 -m owner –gid-owner nonet -j ACCEPT
sudo iptables -A OUTPUT -m owner –gid-owner nonet -j REJECT –reject-with icmp-net-unreachable
  • Run Skype as the nonet group like this-
sudo -g nonet PULSE_LATENCY_MSEC=60 /usr/bin/skype

Skype should not be able to login. Goto Options>Advanced and set the HTTPS proxy to point to squid (default port 3128).

Skype should now be able to login using the proxy (it takes a minute or two though). If not, try restarting Skype.

(Note that you don't even need to enable delay queues for squid to control the bandwidth, at least for me Skype doesn't go over 20KBps Upload/Download when using a proxy.)

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Note that what this is doing is forcing Skype traffic through a Squid proxy. To achieve this, you need to run both a IPTABLES and a Squid proxy, both run on Linux. You could do this on the same machine as Skype (as in this example) or could, with some tweaking, use other servers. – Julian Knight May 29 '15 at 19:15

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