Re: Question related with DAUD Message

On 1/31/07, Barry Nagelberg <[email protected]> wrote:
>
> Oscar,
>
> There is nothing in the RFC which states that "there is no limit to the
> number of point codes in the DAUD (or DUNA or
> DAVA)".


Max limit could be calculated from the  max value of 'length'  parameter

This is an interoperability bug in the RFC, because obviously there must be
> some limit - an SGP could run out of
> resources if the ASP sends it a DAUD msg with a billion point codes. A
> limit of 1024 sounds reasonable to me.


Not billion...we could send maximum 16382 point codes in a DAUD

The main point facing us now is that the size of the limit is an
> implementation decision for each vendor. I suggest that
> the RFC be updated to state explicity what the limit is - otherwise this
> will continue to cause interoperability
> problems.


I agree with you...

Barry Nagelberg
>
> -----Original Message-----
> From: Colmenares, Oscar (Oscar) [mailto:[email protected]]
> Sent: Wednesday, January 31, 2007 12:23 PM
> To: Ankit Kumar Sharma; Colmenares, Oscar (Oscar)
> Cc: Andrew Booth; [email protected]
> Subject: RE: [Sigtran] Question related with DAUD Message
>
>
>
> Ankit
>
>     This part sound better for me, do you have the RFC that mentioned that
> there is not limit on the number of point
> codes in DAUD message, I will need this in order to talk with our SG
> provider??
>
>     Also can I share your email with people from my company and the
> customer???? Or this could be a problem for you?
>
> Regards
>
> Oscar
> -----Original Message-----
> From: Ankit Kumar Sharma [mailto:[email protected]]
> Sent: Miércoles, 31 de Enero de 2007 01:15 p.m.
> To: Colmenares, Oscar (Oscar)
> Cc: Andrew Booth; [email protected]
> Subject: Re: [Sigtran] Question related with DAUD Message
>
>
> I have also faced this problem in past. Some stack vendors limit it on no.
> of point codes in DAUD message and some on
> the length of DAUD message(DAUD message greater than xx limit would get
> discarded).
> If I am not wrong then as per RFC, there isn't any limit on number of
> Point codes in DAUD. If any vendor is not
> following this then its a bug in their stack.
> I think there should be some upper limit set on number of Point codes in
> DAUD for better interworking.
>
> cheers,
> Ankit
>
>
> On 1/31/07, Colmenares, Oscar (Oscar) <[email protected]>
> wrote:
>
> Andrew
>
>         My concern here is that is multiple ASP and SG providers are
> having
> their own interpretation to the standard and we can have inter-operability
> problems in the future.
>
>         So far we as an ASP we are trying to implement multiple point
> codes
> in the same DAUD message and we can support up to 1024 point codes but the
> SG interpretation was to set a limit in the numbers of point codes per
> DAUD
> message up to 16, so we are facing some developments problems due
> different
> interpretations.
>
>         I think it will be a good idea to have a recommendation from the
> Sigtran expert as how this should work in order to align all the ASP and
> SG
> and define a way to use this kind of message.
>
>         So my answer here will be, this help but not enough due there is
> no
> way to decide who is right or wrong performing this setting in the
> message.
>
>         Please if you or your team have recomendations in how to set this
> (something official) please let us know, because this is very important
> for
> us.
>
> Regards
>
> Oscar
>
> -----Original Message-----
> From: Andrew Booth [mailto:[email protected] ]
> Sent: Miércoles, 31 de Enero de 2007 12:18 p.m.
> To: Colmenares, Oscar (Oscar)
> Cc: [email protected]
> Subject: Re: [Sigtran] Question related with DAUD Message
>
>
> I think the ASP can send DAUD in any way it sees fit, according to the
> RFC.
>
> The following comments are my own and are not specified in the RFC.
>
> I think assuming that state is always synchronized is a dangerous
> assumption.  For instance, what if the SG is in overload and discards a
> DAVA?  What if there's a bug on one end or the other?  What if the ASP
> is connected to two SGPs and receives DUNA + DAVA from SGP1 and DUNA +
> association loss from SGP2, in that order?
> The main risk would probably be a missing DAVA, since a missing DUNA
> would get discovered by a response DUNA if traffic is sent to the
> destination.
>
> >From an operational standpoint I'd be careful sending DAUD with a big
> wildcard, since it's difficult to estimate how many responses you might
> get and how fast, so it's hard to avoid potential overloads.  Also, you
> won't necessarily know when you have all the responses (if you care).
>
> Other than that, it's more bandwidth efficient to send multiple affected
> PCs in one message, but that's only a concern if you're running over
> bandwidth constrained networks or auditing many PCs.  So, take your pick.
>
> Does that help?
> Andrew
>
> Colmenares, Oscar (Oscar) wrote:
> > Sigtran Experts
> >
> >       I was looking for some help related with how to set the DAUD
> > message, I was reading some message from HS Jang related when the ASP
> need
> > to use the DAUD message, explain as follow
> >
> > Let me summarize about DAUD in SUA ASP with your postings and my
> > understanding. first of all,
> >  1) ASP does not need to send DAUD in normal situation. because SCCP in
> SG
> > cares it with its mechanism and inform the ASP of the changes in DPC/SSN
> > with SSNM message. i.e. the state information about destinations are
> > synchronized all the time.
> >  2) the only time ASP needs to send DAUD is when the ASP is recovered
> from
> > isolation because ASP has no state information about destinations now. (
> but
> > this is also not necessary for normal operation of data transfer. it is
> only
> > necessary when ASP really wants to know the state information of
> > destinations for example, in the respect of OAM or something )
> > 3) there are mentions about sending DAUD periodically in RFC but it is
> > somewhat wrong.
> >
> >       Now base on these explanation and related with point 2, send DAUD
> > message when the ASP is recovered from isolation, my question is there
> is
> > any rules in other to how to send these point codes?? do we have or must
> > send multiple messages with one point code information per message, or
> send
> > just one message with all the point codes information???
> >
> >       The main idea here is understand if I have a system with multiple
> > point codes, for example 25 point codes, how the standard said we need
> to
> > send the DAUD message, just one message with all the point codes inside
> or
> > 25 single messages with just one point code per message.
> >
> > I really appreciate your help on this question
> >
> > Best regards
> >
> > Oscar
>
>
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