* Pekka Savola: > If there is a transport protocol indication (either via ICMP or via a > refusal to send the datagram as in DCCP Section 14), then DTLS record > layer should inform the upper layer protocol of the error. > > .. is this too weak? I've have thought that it would be natural that if > DTSLS record layer gets this notification (which, in the case of ICMP and > omitting information, is not necessarily given), it MUST pass this > information up. Note that the refusal to send could also apply to UDP > if packet is bigger than PMTU and DF bit is set or IPv6 is used. > What is the alternative if it doesn't? It would be fine if > the alternative is that the DTLS record layer react to that information > itself, but completely ignoring e.g. ICMP packet too big would lead to > communication failure. ICMP packet too big is typically handled by the stack, not the application. The stack updates the stored path MTU, the application tries again, and this time, the stack produces smaller fragments. AFAIUI, requiring ICMP processing in applications prescribes an implementation model based on connected UDP sockets (in the terminology of the BSD sockets API). This is not always desirable or possible. -- Florian Weimer <fweimer@xxxxxx> BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstraße 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99 _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf