Re: sending ASP UP in IPSP SE

Chris,

Management lockout of server and client retrying of server connectivity are
typical
of any client-server communication. It is always the client which is
expected to initiate
a connection by virtue of its role. Lockouts are special cases and there are
ways to deal
with it.

I see little value in keeping the SE ASP*M message exchanges open which
otherwise could
be easily fixed.

regards
Sunderjeet

On Tue, Nov 16, 2010 at 5:38 PM, Chris Benson <[email protected]> wrote:

> Sunderjeet,
>
> One might consider a case where one side is ready, but the
> other side is not.  There is the notion of Management Lockout
> in M3UA (fourth paragraph of RFC 4666 Section 4.3.4.1).
>
> In this case it might be the "server" who was not initially
> ready, and did not respond to the client's ASP Up with an
> ASP Up Ack.  Later, when this "server" becomes ready, it can
> initiate and indicate state change by sending its own ASP Up
> message.
>
> Either side can initiate this and similar state changes at
> any time, e.g. in response to local management actions.
> Your suggested simplification would lose such a capability.
>
> With best regards, from Chris Benson.
>
> On Tue, 16 Nov 2010, Sunderjeet Singh wrote:
>
> >>  Date: Tue, 16 Nov 2010 17:12:25 -0400
> >>  From: Sunderjeet Singh <[email protected]>
> >>  To: Chris Benson <[email protected]>
> >>  Cc: "Jaddu, Suresh (NSN - IN/Bangalore)" <[email protected]>,
> >>      <[email protected]>
> >>  Subject: Re: [Sigtran] sending ASP UP in IPSP SE
>  >>
> >>  As a simplification, can't the role of M3UA client be given to the end
> that
> >>  initiated SCTP association ?
> >>  Since SCTP client behaviour in IPSP communication should be configured
> >>  anyways, giving the same end
> >>  M3UA client fn would be pretty straight. So unless there are compelling
> >>  reasons to keep the ASPUP intiator open
> >>  for IPSP-SE case, this approach could generate a simpler
> implementation.
> >>
> >>
> >>  Sunderjeet, Tech Mgr
> >>  Aricent Technologies (Holdings) Ltd
> >>
> >>
> >>  On Mon, Nov 15, 2010 at 3:13 PM, Chris Benson <[email protected]>
> wrote:
> >>
> >>  > SJ,
> >>  >
> >>  > The short answer is that it doesn't matter much, and all
> >>  > is well if both sides try to come UP around the same time,
> >>  > providing that each receiver of an ASP Up responds with
> >>  > an ASP Up Ack.
> >>  >
> >>  > The state of each IPSP is maintained by the remote (not
> >>  > local) peer M3UA layer.  When one IPSP wishes to enter
> >>  > the UP/Inactive state, it issues a ASP Up message,
> >>  > indicating that it is ready for its state to be changed.
> >>  > If the receiver of the ASP Up "agrees", then it responds
> >>  > with ASP Up Ack.
> >>  >
> >>  > In the Single Exchange model, this SINGLE positive exchange
> >>  > carries the same meaning for the state of both sides.  The
> >>  > initiator is saying "I want to move to the UP/Inactive state
> >>  > and you can too". The [positive] responder is saying "you are
> >>  > now in the UP/Inactive state, and I am too".
> >>  >
> >>  > So to answer your direct question, if both sides initiate
> >>  > ASP Up messages around the same time, all is well, because
> >>  > the two meanings coincide (both sides want to be UP/Inactive).
> >>  > To be successful, the ASP Up message requires an ASP Up Ack
> >>  > message, so both sides respond to an ASP UP message with
> >>  > an ASP UP Ack, and both sides move to the UP/Inactive state.
> >>  >
> >>  > The same argument applies to ASP Active messages etc.
> >>  >
> >>  > This Single Exchange Model requires that there be one Routing
> >>  > Key which fully specifies traffic in both directions.
> >>  >
> >>  >
> >>  >
> >>  > Chris Benson, Software Engineer,
> >>  > Adax Inc., Berkeley, California, USA.
> >>  >    [email protected]
> >>  >    +1 510 548-7047 ext. 189
> >>  >    www.adax.com
> >>  >
> >>  > On Mon, 15 Nov 2010, Jaddu, Suresh (NSN - IN/Bangalore) wrote:
> >>  >
> >>  > >>  Date: Mon, 15 Nov 2010 23:10:01 +0800
> >>  > >>  From: "Jaddu, Suresh (NSN - IN/Bangalore)" <[email protected]
> >
> >>  > >>  To:  <[email protected]>
> >>  > >>  Subject: [Sigtran] sending ASP UP in IPSP SE
> >>  >  >>
> >>  > >>
> >>  > >>  Hi All,
> >>  > >>
> >>  > >>  I think this is very old discussion, I have searched through
> achieves
> >>  > >>  but could not find definitive answer. In IPSP single exchange
> mode how
> >>  > >>  to dentine that which side sends the ASP UP message during
> >>  > >>  initialization. From the archives and also the RFC it looks like
> either
> >>  > >>  side can initiate the M3UA messaging but in the absence of any
> >>  > >>  predefined roles or any prior agreement how to know that which
> side
> >>  > >>  sends the ASP UP.  In such situations it is certainly possible
> that
> >>  > both
> >>  > >>  sides may send the ASP UP if that happens how to handle that, is
> it a
> >>  > >>  valid case?? (if this is valid case then what is recommended
> handling).
> >>  > >>
> >>  > >>  Thanks,
> >>  > >>  SJ.
> >>  > >>
> >>  > _______________________________________________
> >>  > Sigtran mailing list
> >>  > [email protected]
> >>  > https://www.ietf.org/mailman/listinfo/sigtran
> >>  >
> >>
>

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