On 28/06/12 05:22, Kurt Zeilenga wrote: > I guess bandwidth-challedged XMPP networks should be fair and, if they > want to block one real-tine conversation method, block them all.
RTT and audio/video do have a significant technical difference: RTT is in-band, and audio/video (at least as implemented in Jingle) are out-of-band. For in-band protocols the extra traffic (stream of partial messages) goes through the server, whereas in out-of-band protocols, the vast majority of the extra traffic is out-of-band, and the XMPP server only sees some relatively lightweight signalling, which is O(number of calls) rather than O(total length of calls). If Alice and Bob communicate via (say) jabber.org, the Jingle traffic is a cost for Alice, Bob and their respective ISPs, whereas the in-band XMPP traffic is a cost for Alice, Bob and their ISPs, but also for jabber.org. RTT over Jingle + ICE-TCP would be a closer equivalent, if there was a finished XEP for Jingle + ICE-TCP; or in principle, RTT could even go over ICE-UDP like audio and video do, if it can survive packet loss/re-ordering. Now, RTT is considerably "lighter" than audio/video, so it's not necessarily a *significant* bandwidth cost for jabber.org (or whatever server Alice and Bob are using) - but it is extra bandwidth that jabber.org would not otherwise be using. S