eap Mailing List: RE: Proposed Resolution of Issue 188: Packet ordering

[Pasi.Eronen (Pasi.Eronen]

Lauri Tarkkala wrote:
> Am I missing something here, but the bis specification
> is currently stating that EAP is a lock-step protocol.
> 
> In this case, assuming nobody is doing optimizations
> based on predicting peer responses, there should
> be no need for an ordering guarantee. 
> 
> That said, requiring that the lower layer provides
> an ordering guarantee is a good idea considering the
> heritage of EAP. I do not however see this as much
> of an issue for new (or upto-date) implementations,
> which we would be talking about here.

Lower layer ordering guarantees are needed because the 
Identifier field is not required to be ordered. If messages
can be reordered, the peer can't necessarily distinguish
a new EAP Request from a reordered retransmission of an
old request.

See http://www.ietf.org/internet-drafts/draft-ietf-pana-pana-02.txt,
Appendix A for a concrete example.

Best regards,
Pasi