A New Internet-Draft is available from the on-line Internet-Drafts directories. Title : Adaptation Layer Fragmentation Indication Author(s) : Carsten Bormann Filename : draft-bormann-intarea-alfi-00.txt Pages : 13 Date : 2012-04-25 IPv6 defines a minimum MTU of 1280 bytes. Many link layers are more limited in their choice of packet size. Typically, IP adaptation layers for these link layers define a segmentation or fragmentation scheme to transport larger IP packets in multiple link layer packets. Often, adaption layer fragmentation schemes reduce some performance metric, such as the packet delivery rate. Where application or transport protocols have a choice, it would therefore be desirable for them to know about any adaptation layer fragmentation that is going on, so they can choose packet sizes that minimize adaptation layer fragmentation. At the IP layer, fragmentation can be detected using a number of mechanisms used in Packetization Layer Path MTU Discovery [RFC4821]. However, adaptation later fragmentation schemes are often designed to be "transparent", i.e. there is no way at higher layers to find out they had to be employed (except maybe by elaborate measurement schemes targeting one of the impacted performance metrics; this approach does not appear to be viable) [WEI]. The present specification defines a mechanism for IPv6 adaptation layers to indicate the presence of adaptation layer fragmentation, as well as an indication of preferred packet sizes. The main objective of this version of the draft is to present a complete design in order to be able to gauge the complexity of the approach against the gains to be expected from implementing it. Comments are appreciated and should go to the intarea@ietf.org mailing list. A URL for this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-bormann-intarea-alfi-00.txt Internet-Drafts are also available by anonymous FTP at: ftp://ftp.ietf.org/internet-drafts/ This Internet-Draft can be retrieved at: ftp://ftp.ietf.org/internet-drafts/draft-bormann-intarea-alfi-00.txt The IETF datatracker page for this Internet-Draft is: https://datatracker.ietf.org/doc/draft-bormann-intarea-alfi/ _______________________________________________ I-D-Announce mailing list I-D-Announce@ietf.org https://www.ietf.org/mailman/listinfo/i-d-announce Internet-Draft directories: http://www.ietf.org/shadow.html or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
