Re: Re: Traffic handling modes of SGPs

Ilie,

1.5.2.  Address Mapping at the ASP

   To direct messages to the SS7 network, the ASP MAY perform an address
   mapping to choose the proper SGP for a given message.  This is
   accomplished by observing the Destination Point Code and other
   elements of the outgoing message, SS7 network status, SGP
   availability, and Routing Context configuration tables.

   A Signalling Gateway may be composed of one or more SGPs.  There is,
   however, no SUA messaging to manage the status of an SGP.  Whenever
   an SCTP association to an SGP exists, it is assumed to be available.
   Also, every SGP of one SG communicating with one ASP regarding one AS
   provides identical SS7 connectivity to this ASP.

   An ASP routes responses to the SGP that it received messages from;
   within the routing context which it is currently active and receiving
   traffic.

ASPs need to know the distribution method to SGPs by configuration.

There are no management messages to manage the state of an SGP.

When an association exists to an SGP, the ASP assumes that it is capable
of processing traffic for the AS that the ASP has activated to it.

For active-standby, your active SGP could have an association to the
ASP and the standby SGP would not.  If the standby goes active, the
standby would form an association and the previously active SGP would
drop its association.

Alternatively, to act as active-standby within an AS, the stanby SGP can
refuse ASP-ACTIVE for the AS with ERR(Management Blocking) or simply
withhold ASP-ACTIVE Ack and let the ASP fall back to periodic procedure.
When the standby goes active, it can then send ASP-ACTIVE-Ack and the
previously active SGP can send unsolicited ASP-INACTIVE-Ack. (Look in
the spec as to what happens when the ASP receives ASP-INACTIVE-Ack in
the ASP-ACTIVE state for an AS.)

Typically, however, SGPs run in loadshare mode, by nature of the design
of the SS7 network to which they attach.

--brian

Ilie Glib wrote:                            (Fri, 02 Dec 2005 08:35:20)
> Hello Folks,
> 
> is my mail out of topic?
> 
> If you need that I introduce myself, here is some info:
> - at the moment I am looking at SIGTRAN from operation and maintenance
> perspective
> - for a couple of years I am working as a telecommunication engineer
> and SW designer of TMN products in ADD s.r.l. Chisinau
> 
> Of course I am asking about a definition, which is an informative part
> of the SUA RFC, I assume.
> 
> Nevertheless, shall the ASP be able to broadcast its messages to all
> SGPs of an SG? According to the SGP definition in SUA RFC, it seems so
> to me.
> 
> Regards
> 
> Ilie
> 
> On 11/29/05, Ilie Glib <[email protected]> wrote:
> > Hello,
> >
> > SGP concept in RFC 3868 sais
> >
> > "Signalling Gateway Process (SGP) - A process instance of a Signalling
> > Gateway. It serves as an active, load-sharing or broadcast process of
> > a Signalling Gateway"
> >
> > It seems that no other part of the RFC allows SGPs to act in different
> > traffic modes.
> >
> > Is this just a leftover?
> > Or, shall ASPs know the traffic mode type of SGP by configuration?
> > How override can be supported without a NTFY sent from ASPs to SGPs?
> >
> > Thank you in advance
> >
> > Ilie
> >
> 
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-- 
Brian F. G. Bidulock
[email protected]
http://www.openss7.org/