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Re: [Sigtran] In IPSP-IPSP mode what should be the behavior on receiving Notify(AS-PENDING) when AS is already AS-ACTIVE
Hi,
We are not using the latest version of the lksctp. It is the version 1.0.2 which is being used in our product.
I can certainly think of moving to newer version but before that just wanted to confirm if I am not missing something at my end either at M3UA stack or at Application level?
Regards
Deepak
-----Original Message-----
From: Ashwani Kathuria [mailto:ashwani.grps at gmail.com]
Sent: Monday, October 12, 2009 11:41 AM
To: bidulock at openss7.org; Deepak Gunjal; Ashwani Kathuria; sigtran at ietf.org
Subject: Re: [Sigtran] In IPSP-IPSP mode what should be the behavior on receiving Notify(AS-PENDING) when AS is already AS-ACTIVE
Deepak:
Are you using the latest version of Linux kernel SCTP available. If
yes, you can raise this this issue with them else try using latest
version.
--Ashwani
On Sat, Oct 10, 2009 at 1:05 AM, Brian F. G. Bidulock
<bidulock at openss7.org> wrote:
> Deepak,
>
> An SCTP that cannot provide SCTP RI is not usable for
> SIGTRAN for this very reason.
>
> --brian
>
> Deepak Gunjal wrote: (Fri, 09 Oct 2009 20:22:59)
>>
>> Hi Ashwini,
>>
>>
>> Thanks for the response.
>>
>>
>> Now here the problem is that my local SCTP which is nothing but linux
>> kernel SCTP (lksctp) has not sent any kind of notification to local
>> M3UA that the connection is down due to network restart so my M3UA
>> always assumes that everything is up and running fine hence takes no
>> action.
>>
>> My peer is Spectra tool emulating the role of IPSP.
>>
>>
>>
>> Now this leads to a situation where both parties assumes they are
>> behaving correctly and user data can not be exchanged.
>>
>>
>> Strangely Spectra2 though says that ASP is down but it sends the
>> Notify on the existing connection!!
>>
>>
>> Is there a way out to come out of this loop? As per the RFC and
>> mentioned section by you I could not found a resolve to this
>> situation? Any suggestions are welcome.
>>
>>
>> Regards
>>
>> Deepak
>>
>>
>> -----Original Message-----
>> From: Ashwani Kathuria [mailto:ashwani.grps at gmail.com]
>> Sent: Friday, October 09, 2009 6:33 PM
>> To: Deepak Gunjal
>> Cc: sigtran at ietf.org
>> Subject: Re: [Sigtran] In IPSP-IPSP mode what should be the behavior
>> on receving Notify(AS-PENDING) when AS is already AS-ACTIVE
>>
>>
>> Hi Deepak,
>>
>>
>> I think your M3UA stack is correct in sending the Error message but
>>
>> your underlying SCTP should send some restart or down indication to
>>
>> your M3UA stack.
>>
>>
>> 5.2.1. 1+1 Sparing, Withdrawal of ASP, Backup Override
>>
>> ...
>>
>> Note: If the SGP M3UA layer detects the loss of the M3UA peer
>> (e.g.,
>>
>> M3UA heartbeat loss or detection of SCTP failure), the initial ASP
>>
>> Inactive message exchange (i.e., SGP to ASP1) would not occur.
>>
>>
>> So peer M3UA is correct in sending NOTIFY (AS-PENDING) messages but
>>
>>
>> in section 4.3.3
>>
>> If the M3UA layer subsequently receives an SCTP-COMMUNICATION_DOWN
>> or
>>
>> SCTP-RESTART indication primitive from the underlying SCTP layer,
>> it
>>
>> will inform the Layer Management by invoking the M-SCTP_STATUS
>>
>> indication primitive. The state of the ASP will be moved to ASP-
>>
>> DOWN.
>>
>> and in section 4.3.4.5
>>
>> A Notify message reflecting a change in the AS state MUST be sent
>> to
>>
>> all ASPs in the AS, except those in the ASP-DOWN state, with
>>
>> appropriate Status Information and any ASP Identifier of the failed
>>
>> ASP.
>>
>>
>> The question is:
>>
>> As per section 4.3.3 M3UA should change the ASP to DOWN upon detecting
>>
>> SCTP failure and as per section 4.3.4.5 NOTIFY messages are not sent
>>
>> to DOWN ASPs. So why in section 5.2.1 NOTIFY messages are sent to DOWN
>>
>> marked ASPs?
>>
>>
>> -- Ashwani
>>
>>
>>
>> On Fri, Oct 9, 2009 at 2:53 PM, Deepak Gunjal
>> <deepak.gunjal at aricent.com> wrote:
>>
>> >
>>
>> > Hi,
>>
>> >
>>
>> >
>>
>> >
>>
>> > Here is the brief description:
>>
>> >
>>
>> >
>>
>> >
>>
>> > I am running my application emulating the role of a AS having 2 ASP
>> in override mode. Out of 2 ASP one ASP is ACTIVE and other is down.
>>
>> >
>>
>> >
>>
>> >
>>
>> > My application has sent the ASP-ACTIVE to peer IPSP node and
>> received the Notify(AS-ACTIVE). Now I restarted the IP network
>> services and as a result remote IPSP node marks the state of my AS as
>> down and sends an Notify(AS-PENDING) which my M3UA stack treats as
>> "UNEXPECTED" message and does nothing as it has not received any
>> notification from SCTP that connection was down so it keeps the local
>> AS ACTIVE and responds with ERROR message with error code "UNEXPECTED
>> message".
>>
>> >
>>
>> >
>>
>> >
>>
>> > My question is what should be my behavior when AS-PENDING is
>> received?
>>
>> >
>>
>> >
>>
>> >
>>
>> > Regards
>>
>> >
>>
>> > Deepak
>>
>> >
>>
>> > ________________________________
>>
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>> >
>>
>> > _______________________________________________
>>
>> > Sigtran mailing list
>>
>> > Sigtran at ietf.org
>>
>> > https://www.ietf.org/mailman/listinfo/sigtran
>>
>> >
>> _________________________________________________________________
>>
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>
>
> --
> Brian F. G. Bidulock
> bidulock at openss7.org
> http://www.openss7.org/
>
"DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error,please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus."