[p2p-hackers] Ideas for an opensource Skype lookalike

[Greg Bildson]

The username and full name appear to be searchable.  The number of online users appears to be in the 100,000 to 200,000 range.  There is an advanced search that allows all profile information to be searchable.

I wouldn't be surprised if the main index is roughly divided up on keyword prefix ranges amongst the long uptime addressable hosts.  Then again, I wouldn't be surprised if it is a more formal DHT.  Actually, their ability to do full substring searches argues against both of these approaches.  They appear to be doing a broadcast search within a fully distributed index.  The broadcast search ends when a set number of matches are reached.  

Why does this sound ground breaking? 

Thanks
-greg

---------- Original Message ----------------------------------
From: Brad Neuberg <bradneuberg at yahoo.com>
Reply-To: "Peer-to-peer development." <p2p-hackers at zgp.org>
Date: Sat, 13 Mar 2004 15:03:18 -0800 (PST)

>The Skype page claims to have implemented something
>called a "Global Index".  From their web page:
>
>"Global decentralized user directory:
>
>Most instant message or communication software
>requires some form of centralized directory for the
>purposes of establishing a connection between end
>users in order to associate a static username and
>identity with an IP number that is likely to change.
>This change can occur when a user relocates or
>reconnects to a network with a dynamic IP address.
>Most Internet-based communication tools track users
>with a central directory which logs each username and
>IP number and keeps track of whether users are online
>or not. Central directories are extremely costly when
>the user base scales into the millions. By
>decentralizing this resource-hungry infrastructure,
>Skype is able to focus all of our resources on
>developing cutting-edge functionality.
>
>P2P network technologies such as FastTrack (used by
>KaZaA) would be suitable for decentralizing this, if
>not for the fact that these networks are fragmented in
>nature – a search does not reach all nodes in the
>network. Clearly, in order to deliver high quality
>telephony with the lowest possible costs, a third
>generation of P2P technology (“3G P2P”), or Global
>Index (GI) was a necessary development and represents
>yet another paradigm shift in the notion of scaleable
>networks. The Global Index technology is a
>multi-tiered network where supernodes communicate in
>such a way that every node in the network has full
>knowledge of all available users and resources with
>minimal latency."
>
>Does anyone have any idea how they have done this
>securely, reliably, and with low latency? Also, what
>exactly is the "key" into this index (the phone
>number?)  If they have truly achieved this then it is
>ground-breaking work on their part.
>
>Brad