Wednesday, October 13, 2010


Ok, here's something slightly interesting. It has to do with Skype - the only traffic I can see here that isn't building business, or something I'm doing (webpages, ftp, updates, etc.) is Skype, so I guess that's what I live with until I go figure out something new.

Anyways, I've mentioned before about how my Skype account seems to use port 34268 to advertise its existence - UDP packets go in and out through that port, and sometimes a link gets established with one of the associated addresses, and a conversation starts - i.e. my computer gets used as a relay in the Skype network. Sometimes I see the UDP packets go out, looking for another node, and nothing comes back - they go out a few more times, and give up.

So, what I noticed is that tonight, my computer is sending RTP packets, which I haven't seen before, rather than UDP packets. RTP is apparently used for transferring video and audio, especially with VOIP applications. So, Skype is looking for someone accepting video/audio streams, trying to establish an RTP network? I have no idea.

Each of those RTP messages was reciprocated with a UDP response, by the way. Nothing else followed, however - there's a single conversation going on through Skype, leisurely exchanging TCP packets every few dozen seconds, so I would assume this is a text conversation - but it's a one-sided conversation, since my computer is communicating only with one other address! If I were relaying a conversation, I should see connections with two other hosts, not one. Maybe some sort of routing table content is being transferred, updated, etc., very slowly?

That's all I've got.

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