Logic of SIP call routing for Retell AI + Jambonz.cloud (dynamic number substitution)

Java — incorrectly specified categories?

223 USD

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Call SIP Routing Logic for Retell AI + Jambonz.cloud (Dynamic Number Replacement)
Brief Description

I have built (already ready) an outbound calling system using Retell AI.
The flow works as follows:

n8n initiates a call to Retell
Retell makes the call through Jambonz.cloud (important: this is a cloud application, not a self-hosted instance)
Jambonz then sends the call to the local telecom operator
Jambonz is needed because Retell uses elastic SIP trunking, while the local operator does not

Now I need to add additional routing logic between Jambonz and the operator:

Retell can pass a custom SIP header with metadata
For one specific destination number, it is necessary to:
- extract the target number from this metadata
- replace the original dialed number with the extracted one
- then perform the usual call routing
All other calls should go through unchanged

If a certain tag is present in the metadata:
- the number replacement should be as follows: prefix (from metadata) + original subscriber number

Analyze the current architecture and advise where it is better to implement the logic: through Jambonz (task, hook, app) or through a separate webhook server
Implement a simple handler (Node.js or Python) that:
- accepts SIP headers
- applies routing and number replacement rules
- returns the updated destination number
Ensure that this logic applies only to one specific number, while all other calls go through unchanged

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Budget: 10000 UAH Deadline: 2 days

Hello! I am ready to complete this project and have extensive experience in developing various applications.

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