Subject: Re: RE: [Sigtran] Re: M3UA Notify message

From: "TOLGA ASVEREN" <[email-masked]>
Date: Tue, 25 Feb 2003 08:39:11 +0200

Not necessarily because I disagree with some change, but just to clarify
where the changes might take us:
NTFY was used till now only as an advisory message, this will be changed.
Starting/stopping(till now we focused more on starting but why not stopping
also? So SG can decide based on load/other dynamic conditions when to stop
traffic to/from AS) traffic will be controlled by SGP with NTFY.
IMO, this requires still a change to the original AS state machine for
transitions from INACTIVE to ACTIVE and possibly from ACTIVE to PENDING.
In general all this will change the meaning of ASPAC/ASPAC-ACK exchange, it
will mean that ASP is ready to be triggered to send/receive traffic for a
specific AS (something to be determined just by ASP, when the triggering
will happen will be decided by SGP)rather than ASP can start to
send/receive traffic for a specific AS(something to be determined by both
ASP and SGP). I believe this migth require some other changes throughout
the document. For example instead of unsolicited ASPIA-ACK, I would think
SGP should send NTFY(INACTIVE). My opinion is, if we are changing
something, let's do it clean and correct.

IMO, overall this is more than just a clarification, let's decide carefully
to prevent rollbacks (as much as possible).

    Tolga

--- "Srivats P." <[email-masked]> wrote:
> All,
>
> Where do we go from here on this one ? Should we put
> it to a vote or
> something ?
>
> IMO, not stopping traffic when #ASPs < n makes more
> sense to me ...
> however since different people are reading it in
> different ways ...
> the IG should clarify this point.

_______________________________________________
Sigtran mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/sigtran

---

From: "Brian F. G. Bidulock" <[email-masked]>
Date: Tue, 25 Feb 2003 02:15:03 -0700

TOLGA,

TOLGA ASVEREN wrote:                                                                 (Tue, 25 Feb 2003 08:39:11)
> where the changes might take us:

If we cannot agree, we let the RFC stand.

> NTFY was used till now only as an advisory message, this will be changed.

No it will not.  An ASP is not forbidden from acting on any Notify message.
All Notify messages are still advisory.  The ASP can take into consideration
Notify messages, information that it has about other ASPs, the time of day,
direction of the wind, etc.

> traffic to/from AS) traffic will be controlled by SGP with NTFY.

The SG has always been permitted to start or stop traffic when it considers
it necessary and has always been permitted to perform its necessary functions
with the SS7 network.  The SGP can send ASPIA Ack or drop associations any
time it wishes to stop traffic.

> transitions from INACTIVE to ACTIVE and possibly from ACTIVE to PENDING.

It does not.  The SG is only withholding a Notify message as proscribed
by the RFC.

> something, let's do it clean and correct.

No nothing changes here because withholding NTFY(ACTIVE) is already part
of the RFC.  Nothing in the RFC changes.

> to prevent rollbacks (as much as possible).

Not even clarification is required.  The RFC details the necessary actions.

The only thing that needs to be done is strike section 3.15 from the IG
because it conflicts with the RFC (which is fine as it is).

--brian

-- 
Brian F. G. Bidulock
[email-masked]
http://www.openss7.org/

---

From: "Samuel Dur D. Jeyaseelan" <[email-masked]>
Date: Tue, 25 Feb 2003 03:56:07 -0600 (CST)

Brian,

  Alcatel USA, Inc.                  Internet: <userid>@ssd.usa.alcatel.com
  1000 Coit Road, Plano, Texas 75075
  ******* The opinions expressed are not those of Alcatel USA, Inc. *******

> time it wishes to stop traffic.

Please let me know what are we achieving by stopping the traffic in the
following case(n+k - reduntancy)

When 'n' ASPs are active
------------------------
SLS-X  ---->ASP1
SLS-Y  ---->ASP2

When ASP1 goes down
-------------------
SLS-(Y,X)  ----->ASP2

Here 3 cases can be dealt

case 1) If SG receives  message with SLS Y - this traffic can be
        successfully (100%) handled by ASP2 according to the configured
        databse.
 
case 2) If SG receives messages with SLS X and Y - this traffic can be
        successfully (100%) handled by ASP2, provided congestion has not
        occured(according to q.704 section 3.8.2)

case 3) Don't allow SG to process the traffic when n<2 ?????????.
        SG disallows traffic when n=0.

IMO, SG has capability to reroute the traffic to ASP1 and there is no
meaning if SG stops traffic when n < 2.

This is just like a MTP3 link failure concept when link1 goes down ,
traffic carried by link1 will be rerouted to available link. 
All we need to do at SG is just change the SLS-ASP dynamic table to carry
SLS X.

--Samuel

---

From: "Brian F. G. Bidulock" <[email-masked]>
Date: Tue, 25 Feb 2003 03:17:47 -0700

Samuel,

Samuel Dur D. Jeyaseelan wrote:                                                     (Tue, 25 Feb 2003 03:56:07)
> following case(n+k - reduntancy)

I agree.   That is what is provided for in the RFC.  However, section 3.15 of
the IG would require the SG to stop traffic when n < 2.  So, it must be
struck.

--brian