Re: M3UA notify following ASP-up-ack

David,
see my comments below.

----- Original Message ----- 
From: "David Laight" <[email protected]>
To: "sigtran" <[email protected]>
Sent: Tuesday, February 17, 2009 10:02 PM
Subject: Re: [Sigtran] M3UA notify following ASP-up-ack


>> yes, it should, provided this ASP Up Ack message follows the ASP
> transition
>> from ASP-Down to ASP-Inactive, see Section 4.3.4.5 of RFC 4666:
>>
>> "When an ASP moves from ASP-DOWN to ASP-INACTIVE within a particular
> AS, a
>> Notify message SHOULD be sent, by the ASP-UP receptor, after sending
> the
>> ASP-UP-ACK, in order to inform the ASP of the current AS state."
>
> That doesn't explain the presence of the 2nd (and 3rd)
> NOTIFY(AS-INACTIVE)
> in sections 5.1.3 (and 5.1.4).

Don't confuse AS state changes and ASP state changes. These ASPs move from 
ASP-Down to ASP-Inactive and they are sent NOTIFY about the current AS 
state. Regardless of the AS state change.


>
> There is also the presumable assumption that they would be replaced
> by NOTIFY(AS-ACTIVE) if the AS is already active.

NOTIFY always reports the actual AS state, of course. Regardless of state of 
any specific ASP.

>
> If a NOTIFY() isn't generated followning every ASP-UP-ACK [1] then
> with slight reordering of the requests the example in 5.1.4 leaves
> the latter connections no idea of the actual AS state and whether
> they should be sending traffic.

Normally any ASP always learns AS state whenever that ASP moves from 
ASP-Down to ASP-Inactive (I assume that 'SHOULD' is respected in 4.3.4.5). 
Then the ASP will receive notifications on the AS state changes, as long as 
this ASP is not in ASP-Down.


>
> We don't send traffic until we've received an explicit indication
> of AS-ACTIVE. But on a loadshare config the latter connections
> aren't receiving the indication.

Once again: they do receive, as soon as they move from ASP-Down to 
ASP-Inactive.


Sergey Mikhailov.