Re: DRAFT Montreal minutes - X#NodeArchitecture comments
Paul Koning <[email protected]>
| Newsgroups | gmane.ietf.ips |
|---|---|
| Message-ID | <[email protected]> |
>>>>> "William" == William Studenmund <[email protected]> writes: William> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 William> On Aug 17, 2006, at 6:43 AM, Paul Koning wrote: >> A good way to fix this is to add two rules: >> >> 1. If a key is not understood, it is assumed to be a negotiation >> key (and a NotUnderstood reply must be sent). 2. If a declarative >> key is sent, and a reply is received from the other end with that >> key and a value of NotUnderstood, this is a protocol violation >> only if the key is required to be implemented. If it was not >> required (i.e., X# keys) then a NotUnderstood reply must be >> silently ignored. William> I like the proposed fix. The two comments I have are: William> 1) While X# keys are not required to be understood, any William> future "normal" keys we define will also fall into this William> category for existing devices. True. So replace "i.e." by "e.g.". William> 2) I note that a device may chose to pretend it doesn't William> understand a key that isn't mandatory, even though it really William> does. For X#NodeArchitecture, a device may answer with William> differing levels of detail. The lowest level may well be to William> pretend that the key's not understood. In such a case, the William> device MUST fully pretend it doesn't understand, and as per William> rule (1) above, it MUST not offer the key and MUST respond William> with "NotUnderstood." William> Note: this is a different behavior from understanding William> X#NodeArchitecture and choosing not to declare a value to William> the other side. I'm not sure whether that is a distinction without a difference. Does it matter whether you can do that? Do we need any extra text to make it legal to do that? I don't think so; if a key is optional then not implementing it is allowed. "Not implementing" may be a runtime choice, not just a design-time choice. If we do need that text for X#NodeArchitecture, it belongs in the spec for that key, it isn't part of the 3720 fix. paul _______________________________________________ Ips mailing list [email protected] https://www1.ietf.org/mailman/listinfo/ips