80208: No Available Unused Proxy

This error occurs when Proxy cannot assign a compatible masked number to the participant from the Service phone number pool. Proxy does not assign the same proxy number to the same participant across concurrent open or in-progress Sessions, and it selects numbers based on routing rules such as country matching, GeoMatchLevel, and the capabilities required for the conversation type.

• The Service does not have enough available proxy numbers for the number of concurrent Sessions that include the same participant. If one participant is active in overlapping Sessions, that participant needs different proxy numbers for those concurrent assignments.
• All compatible proxy numbers for this participant are already in use in other open or in-progress Sessions, so Proxy cannot safely reuse one without risking conversation collisions.
• The phone number pool does not contain a number that matches the participant's country or the Service GeoMatchLevel requirements. Proxy matches participants to same-country numbers by default, and stricter GeoMatchLevel settings can reduce the set of eligible numbers further.
• The phone number pool does not contain a number with the required capabilities for the interaction. Proxy selects numbers appropriate to the conversation type, and number capabilities vary by country.

• Add more unreserved Twilio phone numbers to the Proxy Service so Proxy has more eligible numbers to assign. Add the numbers to the Service phone number pool before creating more participant assignments.
• Size your pool for concurrency. If the same participant can be active in multiple concurrent Sessions, add at least one additional proxy number for each overlapping Session that participant must support.
• Review your Service GeoMatchLevel and make sure your pool includes numbers in the countries or area codes your participants require. If your current matching rules are stricter than your use case needs, relax them so more numbers qualify.
• Verify that your pool includes numbers with the capabilities your workflow needs, such as Voice, SMS, or both. In countries where capabilities differ by number type, add numbers that match the communication channels you support.
• Close Sessions as soon as they are no longer needed. Because this error occurs when compatible numbers are already in use in other Sessions, shorter overlap windows can reduce allocation failures.

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