On Thu, 13 Sep 2007, Keith Moore wrote: > Offhand I don't know why it should be necessary to build a mechanism > that spans several transport lifetimes. TLS session caches. HTTP cookies. FTP control connections. Apps that want to deal with concurrent data streams within one user's session currently have to establish and authenticate multiple TCP connections (e.g. HTTP, IMAP) or re-implement TCP's multiplexing and windowing at the application level (e.g. BEEP, ssh). A session layer would allow an app to establish a security context once then re-use it when establishing new transport connections, so that re-connecting can be cheap and concurrent data streams can be simple. Unfortunately TCP doesn't share congestion information between connections, which penalises new bulk-data streams and requires workarounds at the application level (e.g. HTTP/1.1 persistent connections). (I have been thinking along similar lines to Karl.) Tony. -- f.a.n.finch <dot@xxxxxxxx> http://dotat.at/ IRISH SEA: SOUTHERLY, BACKING NORTHEASTERLY FOR A TIME, 3 OR 4. SLIGHT OR MODERATE. SHOWERS. MODERATE OR GOOD, OCCASIONALLY POOR. _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf