RE: CIC as a RK

Lincoln,

I agree with your concerns and as a general strategy I would think one can
follow (for the case where CIC ranges are used to define different RKs):

a)Using Override trafic mode for each AS. The standby instance may actually
take over control of the CIC after a failover or just reply back with the
appropriate answer.

b)Using a default fauilure handling ASP, everything, which is received for
an AS, for which there is no ACTIVE ASP is forwarded there. That ASP
constructs the appropriate answer.

c)The SG constructs the appropriate answer and sends it back.


I believe, as long as ASP/SG agree on which model is followed, there
shouldn't be a problem from interoperability point of view. Probably that
agreement could be provisioned both at SG and ASP.

    Thanks,
    Tolga

> -----Original Message-----
> From: Haresign Lincoln [mailto:[email protected]]
> Sent: Wednesday, November 08, 2006 4:07 PM
> To: Ilie Glib
> Cc: [email protected]
> Subject: [Sigtran] CIC as a RK
>
>
> Ilie,
>
> I'm not sure that we have ever answered this basic issue:
>
> Do we want to use CIC as a Routing Key (meaning that I can have separate
> AS with all the same RKs except CIC range).  CIC range will be the
> determining factor for how the SG routes between AS.
>
> Or, do we want to use CIC for loadsharing.  Meaning that the SG will
> choose AS based upon other criteria besides CIC (DPC, OPC, SI), and then
> use CIC to distribute within the AS (similar to TID/DRN in SUA).
>
> I think the second is more practical as it avoids issues of CIC
> management that are apparent in the first case.  To illustrate, I have
> this simple scenario.  We have two different AS.  Each with a single
> ASP.  They share the same PC as the SG, but use a CIC range as RK to
> differentiate the two.
>
>
> ---------
> | AS1   |\
> | PC=1  | \
> | CIC=1 |  \
> ---------   \ |------|
>              \| SG   |
>              /| PC=1 |<====SS7 Network===>
> ---------   / |------|
> | AS2   |  /
> | PC=1  | /
> | CIC=2 |/
> ---------
>
> When AS1 loses the association to SG, how does it handle an incoming IAM
> for CIC=1?
>
> Or if there is a call in progress, how does it handle an incoming REL
> for CIC=1?
>
> These are real scenarios that, if not handled, either affect billing or
> use of network resources.  No network provider will be happy if these
> problems are not solved.  If you expect your SG to interface to somebody
> else's AS, they must be solved in an agreed upon manner.  If it is your
> SG and your AS, no problem.  You can determine some internal solution.
>
> Regards,
> Lincoln
>
>
>
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