Re: [EME] The virtual circuit trap mentioned in the EME charter - need for clarification
Joe Touch <touch@ISI.EDU> Wed, 15 November 2006 16:30 UTC
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Date: Wed, 15 Nov 2006 08:30:12 -0800
From: Joe Touch <touch@ISI.EDU>
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To: Rémi Després <remi.despres@rd-iptech.com>
Subject: Re: [EME] The virtual circuit trap mentioned in the EME charter - need for clarification
References: <E6F7A586E0A3F94D921755964F6BE00662575C@EXCHANGE2.cs.cornell.edu> <4559FC5C.1090803@rd-iptech.com> <455A14AA.6010007@isi.edu> <455B3DDC.2060903@rd-iptech.com>
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Rémi Després wrote: > Thanks for the clear case description. > > IMHO it should be considered more a problem of "NATs that may be passed > around with rerouting" than as a problem of "NATs" as such. > (Most private NATs, that are the majority, cannot be passed around. No > one would say that rerouting creates problems just because it can create > problems when combined with NATs.) Right. It's the NAT that creates the problem, because it's not tolerant of the rerouting. Hard state in the middle of the network is dangerous when paths are not pinned. (e.g., pinning can happen with explicit signalling, or happens with proxies because of the termination of the transport connection). > Also, automatic reestablishment of a broken TCP connection is AFAIK > systematic in common applications (mail, web, FTP etc.). > It can thus be deemed that this failure case not only is "recoverable" > but is even "recovered" in the practical world. > (The recovery is even fast in general if the NAT which takes over, > receiving a non-SYN TCP packet on an unknown connection, does return the > RST which, if not lost, immediately clears the connection.) It'd be useful to decide whether recovery includes the assumption that the app layer will reconnect and restore E2E context. If that's _assumed_ here, it'd be a first IMO. Joe > Joe Touch a écrit : >> Rémi Després wrote: >> >>> 2. I am not aware, personally, of failures of classical NATs that cannot >>> be recovered (I mean those NATs that all of us use extensively).. >>> >> >> When there are multiple NATs that could be used for egress or ingress. >> >> An outgoing SYN establishes state at one NAT that is typically not >> shared with the other NATs; if the routing changes behind the NAT to the >> egress, or in front of the NAT on the return path, the connection >> breaks. FWIW, that routing can change for many reasons, including >> failure of a NAT box itself. >> >> Whether that's recoverable depends on whether you're willing to >> reestablish a connection as part of recovery. >> >> Joe >> >> -- ---------------------------------------- Joe Touch Sr. Network Engineer, USAF TSAT Space Segment
_______________________________________________ EME mailing list EME@irtf.org https://www1.ietf.org/mailman/listinfo/eme
- [EME] The virtual circuit trap mentioned in the E… Rémi Després
- Re: [Fwd: [EME] The virtual circuit trap mentione… Rémi Després
- RE: [EME] The virtual circuit trap mentioned in t… Paul Francis
- Re: [EME] The virtual circuit trap mentioned in t… Rémi Després
- Re: [EME] The virtual circuit trap mentioned in t… Joe Touch
- Re: [EME] The virtual circuit trap mentioned in t… Scott W Brim
- Re: [EME] The virtual circuit trap mentioned in t… Rémi Després
- RE: [EME] The virtual circuit trap mentioned in t… Paul Francis
- Re: [EME] The virtual circuit trap mentioned in t… Rémi Després
- Re: [EME] The virtual circuit trap mentioned in t… Rémi Després
- Re: [EME] The virtual circuit trap mentioned in t… Rémi Després
- Re: [EME] The virtual circuit trap mentioned in t… Joe Touch
- [EME] transport recovery at the APP layer ? Rémi Després
- [EME] Re: transport recovery at the APP layer ? Joe Touch
- RE: [EME] Re: transport recovery at the APP layer… Henry Sinnreich
- Re: [EME] Re: transport recovery at the APP layer… Joe Touch
- [EME] Re: transport recovery at the APP layer ? Rémi Després
- RE: [EME] Re: transport recovery at the APP layer… Paul Francis
- Re: [EME] Re: transport recovery at the APP layer… Rémi Després
- RE: [EME] Re: transport recovery at the APP layer… Paul Francis
- [EME] Re: transport recovery at the APP layer ? Joe Touch
- Re: [EME] Re: transport recovery at the APP layer… Joe Touch
- Re: [EME] Re: transport recovery at the APP layer… Yangwoo Ko
- [EME] Re: transport recovery at the APP layer ? Rémi Després
- Re: [EME] Re: transport recovery at the APP layer… Saikat Guha
- Re: [EME] Re: transport recovery at the APP layer… Joe Touch
- Re: [EME] Re: transport recovery at the APP layer… Mark Baker
- Re: [EME] Re: transport recovery at the APP layer… Joe Touch
- Re: [EME] Re: transport recovery at the APP layer… Mark Baker
- Re: [EME] Re: transport recovery at the APP layer… Joe Touch
- Re: [EME] Re: transport recovery at the APP layer… Mark Baker
- Re: [EME] Re: transport recovery at the APP layer… Saikat Guha
- Re: [EME] Re: transport recovery at the APP layer… Joe Touch
- [EME] Relationship betwen Rémi Després
- [EME] TCP close semantics Rémi Després
- [EME] Re: TCP close semantics Joe Touch
- [EME] Re: TCP close semantics Rémi Després
- Re: [EME] Relationship betwen Lars Eggert