Forward InitialDPRequest

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barbos...@gmail.com

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Dec 24, 2020, 5:33:53 AM12/24/20
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Hello to all,

Does anybody know how to forward CAMEL call correctly?
I have to note that forward should be done after InitialDPRequest event will be received, analyzed and the decision to forward would take place.

I've tried to create a new capDialog with localTxId same as remoteTxId of initial capDialog and forward that way, but here I have the problem that localTxId can exist in active TCAP dialogs, and as a result, I may get an exception: TCAPException("Suggested local TransactionId is already present in system: " + id)
This way can cause problems in the production platform as we can't guarantee the unexistence of localTxId same as remoteTxId.

Any help would be kindly appreciated.

Best regards,
Sergey Yashchenkov

Vilius Panevėžys

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Jan 5, 2021, 6:54:43 AM1/5/21
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On Thu, 24 Dec 2020 02:33:53 -0800 (PST)
"barbos...@gmail.com" <barbos...@gmail.com> wrote:

> Does anybody know how to forward CAMEL call correctly?
> I have to note that forward should be done after InitialDPRequest
> event will be received, analyzed and the decision to forward would
> take place.

Hello Sergey,
call forwarding would typically be done using CAP Connect.

> I've tried to create a new capDialog with localTxId same as
> remoteTxId of initial capDialog and forward that way, but here I have
> the problem that localTxId can exist in active TCAP dialogs, and as a
> result, I may get an exception: TCAPException("Suggested local
> TransactionId is already present in system: " + id)
> This way can cause problems in the production platform as we can't
> guarantee the unexistence of localTxId same as remoteTxId.

I suppose you're actually thinking about proxying TCAP payload
transparently. That should be easier by working at one level below TCAP
- SCCP. You would then likely have to parse up to CAP manually (which,
of course, does not mean re-implementing anything that's already
available in jSS7), but otherwise you have the problems you've
outlined above.

My knowledge of jSS7 APIs is limited and rusty, so I can only offer
basic ideas. It could be a little simpler if jSS7 allows you to access
raw TCAP payload when working at CAP level. That way you could work at
CAP level on the "incoming" side for easy IDP analysis and at SCCP level
on the "outgoing" side. You'll have to check the APIs to see if that's
feasible, though. Otherwise, it would have to be SCCP on both sides and
a little bit more glue to parse the payload up to CAP to then possibly
forward the raw TCAP payload.

Happy proxying!


--
Vilius Panevėžys
Elitnet
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