Christian Amsüss wrote: > This is something that servers, especially proxies, should not try to > enforce, because every case of a request with differing options (or > FETCH payload) could just as well be a new observation from the client > on the token whose observation cancellation got lost, or the client > simply rebooted.
If it's a new observation, then the client should not use a token that is still in use. RFC 7252 Section 5.3.1: The client SHOULD generate tokens in such a way that tokens currently in use for a given source/destination endpoint pair are unique. This requirement is slightly relaxed when a client wants to re-register its interest in a resource, but only under narrow circumstances: namely that the request is (almost) identical. This is a requirement for clients, however. In case a server (or proxy in the role of a server) receives an observation request with a token that is still in use, it must kill the existing observation. RFC 7641 Section 4.1: The entry in the list of observers is keyed by the client endpoint and the token specified by the client in the request. If an entry with a matching endpoint/token pair is already present in the list (which, for example, happens when the client wishes to reinforce its interest in a resource), the server MUST NOT add a new entry but MUST replace or update the existing one. So the server already doesn't enforce the client requirement. Klaus _______________________________________________ Lwip mailing list [email protected] https://www.ietf.org/mailman/listinfo/lwip
