Hi, Gerhard Thanks for your comments, I read the proposals, I can see it's a good idea to solve the dtls/udp's flaw. "time-out" is a solution, but it's disadvantage here is hard to decide an appropriate least round trip times, A short "time-out" will cost the dtls client large calculation expense. Providing a "heart-beat" solution the sender needn't renegotiation at each round trip time of "heart-beat", which may set a longer resume-session time and renegotiation time according to its strategy. I prefer a "heart-beat" solution than a "time-out" solution for this issue.
The only thing left here for syslog-dlts is if we need specific using "heart-beat" in a syslog-dtls proposal? It's a problem of dtls/udp, which can be fixed in the implementation of dtls and as a part of dtls protocol. There's anything need syslog-dtls to do to support it? what's your consideration? Thanks Linda ----- Original Mail ----- 发件人: [email protected] 日期: 2009年 7月 29日, 星期三, 上午3:02 主题: Syslog Digest, Vol 47, Issue 9 收件人: [email protected] > If you have received this digest without all the individual message > attachments you will need to update your digest options in your list > subscription. To do so, go to > > https://www.ietf.org/mailman/listinfo/syslog > > Click the 'Unsubscribe or edit options' button, log in, and set "Get > MIME or Plain Text Digests?" to MIME. You can set this option > globally for all the list digests you receive at this point. > > > > Send Syslog mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.ietf.org/mailman/listinfo/syslog > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Syslog digest..." > > > Today's Topics: > > 1. Missing dead peer detection in DTLS (Gerhard Muenz) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 28 Jul 2009 10:41:31 +0200 > From: Gerhard Muenz <[email protected]> > Subject: [Syslog] Missing dead peer detection in DTLS > To: [email protected], "[email protected]" <[email protected]> > Cc: Michael Tuexen <[email protected]>, Robin Seggelmann > <[email protected]>, Daniel Mentz <[email protected]> > Message-ID: <[email protected]> > Content-Type: text/plain; charset="iso-8859-1" > > > Hi, > > This mail goes to the ipfix and syslog mailing lists in order to > summarize the common issues regarding DTLS. > > IPFIX specifies support of DTLS as mandatory for transport over UDP and > SCTP in RFC5101. In SYSLOG, it is intended to standardize DTLS for > transport over UDP. > > In IPFIX, we have a first implementation of IPFIX-over-DTLS/UDP, and > we > will have a first implementation of IPFIX-over-DTLS/SCTP very soon. > During this implementation effort, we found that the current > specification of DTLS/UDP has a severe flaw when used with > unidirectional protocols (like IPFIX): The sender cannot recognize if > the receiver has crashed and lost the DTLS state. > > We discuss this issue in a draft: > http://tools.ietf.org/html/draft-mentz-ipfix-dtls-recommendations-00 > http://www.ietf.org/proceedings/75/slides/ipfix-6.pdf > > I've had a look at draft-feng-syslog-transport-dtls-01 and > draft-petch-gerhards-syslog-transport-dtls-02. It seems that this > problem has not yet been covered, although the problem should be the > same for SYSLOG. > > As a solution, the DTLS Heartbeat Extension has been proposed very recently: > http://tools.ietf.org/html/draft-seggelmann-tls-dtls-heartbeat-00 > A feature patch for OpenSSL is available: > http://sctp.fh-muenster.de/dtls-patches.html#features > > So, I think that we should support this standardization initiative as > it > solves our problem. For IPFIX and SYSLOG over DTLS/UDP, we then can > specify that the DTLS Heartbeat Extension MUST be implemented. > > Dan suggested to have a single document solving the DTLS issues > regarding unidirectional protocols. I think that such a document is not > needed if we have DTLS Heartbeat Extension. > > Regards, > Gerhard > > -- > Dipl.-Ing. Gerhard M?nz > Chair for Network Architectures and Services (I8) > Department of Informatics > Technische Universit?t M?nchen > Boltzmannstr. 3, 85748 Garching bei M?nchen, Germany > Phone: +49 89 289-18008 Fax: +49 89 289-18033 > E-mail: [email protected] WWW: http://www.net.in.tum.de/~muenz > > > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: smime.p7s > Type: application/x-pkcs7-signature > Size: 3467 bytes > Desc: S/MIME Cryptographic Signature > Url : < > > ------------------------------ > > _______________________________________________ > Syslog mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/syslog > > > End of Syslog Digest, Vol 47, Issue 9 > ************************************* > _______________________________________________ Syslog mailing list [email protected] https://www.ietf.org/mailman/listinfo/syslog
