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gmane.ietf.sigtran |
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<[email protected]> |
Brian,
Actually the traces were taken after the peer host crashed.
Since the M3UA ASPUP message is sent only after the lower layer SCTP
association is established (SCTP INIT and SCTP INIT ACK), does the
sending of the M3UA ASPUP message in this scenario indicate that the
SCTP association has been already established or is that undeterminable
on account of the peer host crashing.
Does it mean that the behavior of the ASP client in this case is normal
considering that the host had crashed?
Thanks
Edwin
>-----Original Message-----
>From: ext Brian F. G. Bidulock [mailto:[email protected]]
>Sent: Saturday, February 11, 2006 2:40 PM
>To: Premkumar Edwin (Nokia-NET/Dallas)
>Cc: [email protected]
>Subject: Re: [Sigtran] M3UA ASP UP message format
>
>Edwin,
>
>A little more information is in order: are these ASPUP
>messages (TSNs) being sent for the first time? If so, perhaps
>the designer took the "and resend ASP Up messages until it
>receives an ASP Up Ack message"
>too literally; the intention was to resend one ASP Up with
>each timer expiry. If they are being retransmitted (e.g.
>because the peer host crashed), it could be more normal.
>
>The retransmission of ASPUP is a purely optional procedure
>(the "MAY"), and is questionable at best on a reliable
>transport. (The M3UA spec leaves the door open, a crack, for
>unreliable transport.)
>
>A better procedure for reliable transport is to notify
>management on expiry of the timer rather than resending ASP Up
>(but note clearly the "MAY" on the procedure). Also, once the
>timer has expired a number of times, (say 60), generate a more
>critical alarm (but keep waiting).
>
>--brian
>
>
>[email protected] wrote: (Sat, 11 Feb
>2006 13:40:26)
>> Hi,
>>
>> I have a question regarding the format of the M3UA ASP UP message
>> initiated by the ASP to the SGP.
>>
>> I wanted to know if this is a valid format according to the
>specs. RFC
>> 3332 section 4.3.4 ASPM Procedures for Peer-to-Peer Messages
>mentions
>> that M3UA ASP UP can be retransmitted after Timer T(ack) expires.
>> "When the ASP sends an ASP Up message it starts timer T(ack). If the
>> ASP does not receive a response to an ASP Up message within T(ack),
>> the ASP MAY restart T(ack) and resend ASP Up messages until it
>> receives an ASP Up Ack message. T(ack) is provisionable,
>with a default of 2 seconds."
>>
>> No. Time Source Destination
>> Protocol Info
>> 23 2006-01-27 23:04:37 10.4.82.54 10.169.97.204
>M3UA (RFC
>> 3332) ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP
>> ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP ASPUP
>> ASPUP ASPUP ASPUP ASPUP
>>
>> The entire packet expanded has been attached in the text file.
>>
>>
>> <<m3ua_aspup.txt>>
>> Thanks
>> Edwin
>
>
>--
>Brian F. G. Bidulock
>[email protected]
>http://www.openss7.org/
>