3 ms·

Er... why didn't they just use XMPP? I haven't used facebook chat much, but the times that I have used it, it has proven to be a lot more unreliable compared to

• mononcqc 17y ago
  Having evaluated some XMPP solutions (over BOSH), one of the problems I have had with it was about the openness of the protocol. You need to tweak the server a whole lot if you want to close down what your users can do and from where they can do it; it becomes complex to synchronize all the data from the backend of the site: who ignores who, privacy settings, friend lists, etc. Another problem that I had encountered was about BOSH. From what I had read in the RFCs, the BOSH session is based on random seed that you hash over and over in SHA (say 200 times). The server then just has to SHA your message to find the hash of the previous message. This, coupled with the basic session identifiers effectively makes it relatively complex to have the chat working over multiple windows or tabs. There might be other reasons, but those are the obvious ones to me.