Subject: [Fwd: Re: [Pana] Another issue in draft-ietf-pana-statemachine-00]

From: Victor Fajardo <[email-masked]>
Date: Thu, 07 Jul 2005 12:31:30 -0400

Subject: Re: [Pana] Another issue in draft-ietf-pana-statemachine-00
From: Victor Fajardo <[email-masked]>
To: Sasikanth Bharadwaj <[email-masked]>
Cc: [email-masked]
Date: Thu, 07 Jul 2005 09:07:39 -0400

>This looks like an issue to me in the PaC state machine
>
>In WAIT_EAP_MSG State
>
>EAP_RESP_TIMEOUT         if (key_available())       WAIT_PAA
>                              PAN.insert_avp("MAC");
>                            PAN.S_flag=PAR.S_flag;
>                            PAN.N_flag=PAR.N_flag;
>                            Tx:PAN();The PAN goes without EAP payload when
>EAP_RESP_TIMEOUT occurs. Whenthe EAP_RESPONSE event occurs, the PaC is in
>the WAIT_PAA state whichdoes not handle this event. The PAA receives the PAN
>and waits for thePAR which never comes. Think this event has to be handled
>in theWAIT_PAA stateThanksSasikanth
>  
>
I think it migth be better if we don't handle EAP_RESP_TIMEOUT in 
WAIT_PAA for the following reasons:

1. The PANA fsm should only anticipate any EAP events and interaction 
within WAIT_EAP_MSG or other PANA-EAP interface states. Adding EAP 
interface events on states where the PANA FSM is not expecting any EAP 
interaction creates overly complex fsm and breaks the syncrhonicity of 
the protocol. Imagine trying to send a PAN when handling 
EAP_RESP_TIMEOUT in WAIT_PAA when your actually waiting for the PAR ...

2. In the scenario stated above, if EAP_RESP_TIMEOUT occurs and the PaC 
sends an PAN without an EAP payload then the EAP fsm on the PAA should 
re-transmitt the last EAP request and hopefully the EAP fsm on the PaC 
will respond before EAP_RESP_TIMEOUT. If the EAP fsm on the PaC always 
responds after an EAP_RESP_TIMEOUT then there must be something wrong 
with the implementation :) ....

3. In your scenario, you mentioned the PAA receives the PAN and waits 
for the PAR. As noted in (2), the PAA should use a new PAR when the EAP 
fsm retransmitts the EAP request.

regards,
-- victor fajardo

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