Murus and Skype - any way to throttle?

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Joined: Mon May 02, 2016 6:24 am

Murus and Skype - any way to throttle?

Post by eskachig » Mon May 02, 2016 6:28 am

I'm trying to limit Skype's uploading bandwith. I understand the application creates new threads and opens random ports. But I have no idea how to create a rule that would connect them through a slowed down pipe.

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Joined: Wed Dec 10, 2014 5:20 pm

Re: Murus and Skype - any way to throttle?

Post by hany » Fri May 06, 2016 12:10 pm

Yes you can do this, but it has some culprits. I mean, Murus is a front end for pf, and pf is a network firewall. So, being a “network firewall”, is unable to recognize which application is connecting to the Internet, it is only able to filter traffic to/from specific ports/addresses.
So, to effectively limit Skype bandwidth you have to identify which ports Skype is actually using. And, unfortunately, Skype uses a different port for each call, in a “hidden” fashion, so you have to make a trick.
You need to limit port over a range of ports, not only a single port. And this port range should be quite big. Doing this will have a side effect: all applications that make use of this ports will have a limited bandwidth. Luckily, a lot of common services (like web browsing and email) do not use these ports, so they are not limited.
So, at the end, you can browse and mail at full speed while having a very low Skype bandwidth.

To do it in Murus:
- create a custom service for Skype, name it “SKYPE" and assign ports from 10000 to 65535, protocol ALL (use 2000:65535 in case it does not work)
- drag this service to outbound managed services
- create a 150 Kbits/s pipe within the Murus bandwidth throttle view
- select the SKYPE service in outbound managed services and click the Bandwidth button (it’s a small round grey button with a meter inside, on the top-left of selected service)
- in the SKYPE bandwidth view assign your pipe to both download and upload
- click PLAY in Murus toolbar to start pf
- Make a Skype call and monitor your bandwidth with OS X’s Activity Monitor (found in Applications/Utility) or using your favourite bandwidth meter tool.

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