Are You a Skype Supernode?

If you run Skype outside of a NAT configuration, you may be passing traffic as a supernode. Skype’s documentation claims the impact of this extra traffic is negligible, but you can prevent your Skype client / connection from becoming a supernode altogether:

  • Beginning with Skype 3.0, an explicit switch is provided in the registry settings to allow the disabling of supernode functionality.
  • Any computer hosted on a network that is behind a network address translation (NAT) device or restrictive firewall will disable supernode functionality.
  • Skype clients behind an HTTP or SOCKS5 proxy will not serve as supernodes.

I’m guessing that most of you are behind a router with NAT, but the University of Waterloo has a fantastic wiki page with further Skype tweaks in relation to the supernode feature.

6 thoughts on “Are You a Skype Supernode?”

  1. Some studies have show that if you don’t allow skype to start on boot you don’t qualify as a supernode…

  2. Your University of Waterloo reference contradicts your statement that Skype will not become a supernode if behind a NAT device.

    Who is correct?
    Thanks
    HB

    https://www.cs.uwaterloo.ca/twiki/view/CF/SkypeConfiguration
    Using Skype behind a NAT – note for home users of Skype behind a router
    “A firewall that blocks inbound traffic or uses NAT (Network
    Address Translation) also won’t stop Skype. When a Skype client starts,
    it opens a session with a supernode in the Skype network.

    If the client cannot be contacted from the Internet, the supernode will
    notify the client when a call comes in?via the open connection. If the
    recipient cannot directly contact the sender, the supernode or a relay
    agent can then act as a proxy between the two callers. “

  3. Skype has created about 50 NAT sessions+, and since we have 30 users in the building that has killed our Router (somehow a bunch of our users became supernodes, or at least, are opening up a bunch of useless active NAT sessions). The
    https://www.cs.uwaterloo.ca/twiki/view/CF/SkypeConfiguration
    registry fix does not seem to help (perhaps the clients aren’t supernodes, but that many NAT sessions is wrong).

  4. “Your University of Waterloo reference contradicts your statement that Skype will not become a supernode if behind a NAT device.

    Who is correct?
    Thanks
    HB”

    That is not a contradiction. The UofW site says that NAT won’t stop Skype, it does NOT say that “NAT won’t stop you from becoming a supernode”

    Forgive me for the double negatives above, but that is how I can logically define how HB has misinterpreted the UofW site.

    Basically, HB, you are confusing “using Skype” with “being a supernode”. You can do the first without being the latter.

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