I have run across an interesting question for doing validation of subscriptions that I would like to get an opinion on.
When doing a publish, there is not an issue. One simply takes the set of values in the scope field as topic filters and checks the publication topic against the set of permissible publication topic filters in the scope. When doing a subscribe, there are four distinct cases that can arise: 1. The subscription is for a single topic and either is or is not successfully matched against the scope topic filter. 2. The subscription is for a topic filter and it is identical to the scope topic filter. 3. Both are topic filters and are not the same. Is one supposed to do some type of subset matching on the two filters or does one always say that this is not a match. This is not addressed in the MQTT document and I am not sure where it would be addressed. As an example: Scope value is subscribe_sport/# Subscription topic is sport/tennis/# The second is clearly a subset of the first and thus it would seem logical to include it, but it gets more complicated if one instead asks for Subscription topic is sport/+ In this case the two wild cards are not the same value. Jim _______________________________________________ Ace mailing list Ace@ietf.org https://www.ietf.org/mailman/listinfo/ace
