3 ms·

While I congratulate Skype on reaching 40M simultaneous users, I am somewhat disappointed that there was no mention of how the 40M people can stay online withou

While I congratulate Skype on reaching 40M simultaneous users, I am somewhat disappointed that there was no mention of how the 40M people can stay online without melting Skype's servers. Some architectural insight would have been nice from an article posted on the front page of HN...

rprasad 15y ago
Skype uses P2P to handle the majority of "call" data, so the load on their servers increases less than proportionately as the number of users increases.
TazeTSchnitzel 15y ago
Skype only gives the appearance of being centralised. It's almost all P2P.
danyork 15y ago
Skype uses a peer-to-peer network for the majority of the connections and really only uses servers for authentication and for gateways to other services/networks (such as the regular phone network). A couple of years ago I wrote a brief description of the technology underlying Skype: http://www.disruptivetelephony.com/2010/11/a-brief-primer-on-the-tech-behind-skype-p2psip-and-p2p-networks.html http://www.disruptivetelephony.com/2010/11/a-brief-primer-on... (I have no connection to Skype myself, but have worked in the VoIP industry for 10 years and have been writing about Skype for a good portion of that time.)
- mirkules 15y ago
  Cool, thanks for the link. If I understood correctly from your article, supernodes are basically Skype clients that act as distributed servers used for discovery of other clients. But I imagine authentication has to happen against a Skype server, and the clients would have to constantly communicate with that server to stay online, to get the current balance, etc... That's 40M requests at any given time. Since it's semi-distributed, and you have to pay for the service (to call a landline or internationally, for example), how does this fit into the distributed model and how do they keep track of everyone?

3 ms·

While I congratulate Skype on reaching 40M simultaneous users, I am somewhat disappointed that there was no mention of how the 40M people can stay online withou

by mirkules 15y ago

rprasad 15y ago
Skype uses P2P to handle the majority of "call" data, so the load on their servers increases less than proportionately as the number of users increases.
TazeTSchnitzel 15y ago
Skype only gives the appearance of being centralised. It's almost all P2P.
danyork 15y ago
Skype uses a peer-to-peer network for the majority of the connections and really only uses servers for authentication and for gateways to other services/networks (such as the regular phone network). A couple of years ago I wrote a brief description of the technology underlying Skype: http://www.disruptivetelephony.com/2010/11/a-brief-primer-on-the-tech-behind-skype-p2psip-and-p2p-networks.html http://www.disruptivetelephony.com/2010/11/a-brief-primer-on... (I have no connection to Skype myself, but have worked in the VoIP industry for 10 years and have been writing about Skype for a good portion of that time.)
- mirkules 15y ago
  Cool, thanks for the link. If I understood correctly from your article, supernodes are basically Skype clients that act as distributed servers used for discovery of other clients. But I imagine authentication has to happen against a Skype server, and the clients would have to constantly communicate with that server to stay online, to get the current balance, etc... That's 40M requests at any given time. Since it's semi-distributed, and you have to pay for the service (to call a landline or internationally, for example), how does this fit into the distributed model and how do they keep track of everyone?