Subject: RE: [SUA Issue] Hop Counter

From: Verwimp Gery <[email-masked]>
Date: Fri, 31 Aug 2001 10:04:11 +0200

Klaus,

I agree with your arguments. There's no reason why SUA couldn't adopt hop
counter as mandatory. The SCCP-user has no control over it, so there's no
interface issue with existing applications on either SG or AS. Also, when
hop counter is not used in the SS7 network (strictly UDT) the NIF just
strips it off. If no hop counter is received (UDT), the NIF populates it
with zero or any value it deems fit before sending CLDT to the ASP.

However, I could live with this parameter being optional, since the "simple"
architectures (backhaul etc.) do not really need it. At least it's there and
it must be handled when received !

____________________________

Gery Verwimp
> SIEMENS ATEA
> ICN D CS D5
> Tel. : +32 14 25 3424
Fax : +32 14 25 3212
mailto:[email-masked]
____________________________________

-----Original Message-----
From: Gradischnig, Klaus [mailto:[email-masked]]
Sent: donderdag 30 augustus 2001 22:43
To: sigtran
Subject: RE: [SUA Issue] Hop Counter

Sorry, but these are not valid arguments. With these arguments the hop
counter would have been prevented to be mandatory in (L/X)UDT(S) messages.
Making the hop counter mandatory in SUA does not pose any interworking
problems. The SUA can always add it with a default value, or drop it in the
SG, if not provided/supported. 

Klaus

> -----Original Message-----
> From: Brian F. G. Bidulock [mailto:[email-masked]]
> Sent: August 30, 2001 3:16 PM
> To: sigtran
> Subject: Re: [SUA Issue] Hop Counter
> 
> 
> John,
> 
> It is optional for connection-less unitdata in that the
> implementation can always choose to send UDT(S) where
> conditions permit and which does not include hop counter.
> 
> Also, don't assume that the most current version of a
> standard is the only version in operation.
> 
> Hop counter should be optional (not mandatory) in CLDT,
> CLDR and CORE.
> 
> --brian
> 
> John Schantz wrote:                           (Thu, 30 Aug 
> 2001 11:57:55)
> > You have to be aware of the timeline of when all of this 
> happened.  UDT,
> > UDTS, CR, etc. were around long time before it was decided 
> that messages are
> > getting bigger and there was a need to handle larger 
> messages.  Hence, the
> > creation of XUDT and XUDTS.  When these were created, it 
> was decided that a
> > "hop counter" would be added to address the concern about 
> circular routes
> > that could exist by GTT.  Therefore, we fixed what was 
> missing from before.
> > LUDT and LUDTS came out even later.
> > 
> > It is only optional in the XUDT(S) & LUDT(S) in that it can 
> be set to 0
> > (zero).  It is a fixed parameter that is always present in 
> the XUDT(S) &
> > LUDT(S).  It is only required to be set to a non-zero value 
> if the message
> > is to be routed on GT.
> > 
> > > -----Original Message-----
> > > From: Brian F. G. Bidulock [mailto:[email-masked]]
> > > Sent: Thursday, August 30, 2001 1:46 PM
> > > To: sigtran
> > > Subject: Re: [SUA Issue] Hop Counter
> > > 
> > > 
> > > Klaus,
> > > 
> > > In SS7 Hop Counter is optional in CR, mandatory in 
> > > XUDT/XUDTS/LUDT/LUDTS,
> > > but is not present in any other messages (that includes 
> UDT/UDTS).  No
> > > procedure which includes Hop Counter can be made mandatory at 
> > > all times.
> > > The procedure is optional even in SS7.
> > > 
> > > It is clear that Hop Counter should be optional in CORE, CLDR 
> > > and CORE,
> > > as it is in SS7.
> > > 
> > > --brian
> > > 
> > > Gradischnig, Klaus wrote:                            (Thu, 30 
> > > Aug 2001 08:46:22)
> > > >
> > > > Gery,
> > > > 
> > > > I fully support your position. The hop counter and its use 
> > > as described by
> > > > you has to be made mandatory in SUA. Anything else defeats 
> > > its purpose.
> > > > 
> > > > Klaus
> > > > 
> > > > > -----Original Message-----
> > > > > From: Verwimp Gery [mailto:[email-masked]]
> > > > > Sent: August 28, 2001 9:32 AM
> > > > > To: sigtran
> > > > > Subject: RE: [SUA Issue] Hop Counter
> > > > > 
> > > > > 
> > > > > John,
> > > > > 
> > > > > Hop counter is mandatory for CLDT, CLDR and CORE (all 
> > > that can be routed
> > > > > on GT).  Procedures apply to decrement the hop counter 
> > > whenever GTT/AMF is
> > > > > invoked to prevent loops.
> > > > > 
> > > > > There's also no reason why the hop counter value can't be 
> > > transparently
> > > > > passed between SCCP and SUA at the SG. The perceived 
> > > "impossibility" again
> > > > > comes from an incorrect view of the NIF as "SCCP or 
> > > SUA-user", which
> > > > > doesn't have the hop counter in the "user interface". But 
> > > the NIF is any
> > > > > possible interworking between SCCP and SUA at the SG.
> > > > > 
> > > > > Regards,
> > > > > 
> > > > > ____________________________
> > > > > 
> > > > > Gery Verwimp
> > > > > > SIEMENS ATEA
> > > > > > ICN D CS D5
> > > > > > 
> > > > > > Tel. : +32 14 25 3424
> > > > > Fax : +32 14 25 3212
> > > > > mailto:[email-masked]
> > > > > ____________________________________
> > > > > 
> > > > > 
> > > > > -----Original Message-----
> > > > > From: [email-masked] [mailto:[email-masked]]
> > > > > Sent: dinsdag 28 augustus 2001 14:18
> > > > > To: sigtran
> > > > > Subject: [SUA Issue] Hop Counter
> > > > > 
> > > > > 
> > > > > Hi all,
> > > > > 
> > > > > Currently, Hop Counter has no home.  It has been 
> removed from the 
> > > > > Flags/QoS Parameter.
> > > > > 
> > > > > I will entertain discussion on this for the next few days.
> > > > > 
> > > > > The issue is: 
> > > > > 
> > > > > Is a Hop Counter needed.  If so, what messages 
> > > (mandatory/option) is
> > > > > it present in & when is it decremented.
> > > > > 
> > > > > John
> > > > > 
> > > > > 
> > > 
> > > -- 
> > > Brian F. G. Bidulock
> > > [email-masked]
> > > http://www.openss7.org/
> > > 
> > > 
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> -- 
> Brian F. G. Bidulock
> [email-masked]
> http://www.openss7.org/
> 
> 
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