A: Great question — Japan is one of the few markets where caller-ID behavior is very sensitive to routing, so you’re absolutely right to ask this up front.

I’ll answer each point directly and precisely.

Short version (TL;DR)
• Yes, JP → JP calls must stay on domestic Japan routing (Tokyo edge) to preserve Caller ID.
• Dialora supports this, but Caller ID preservation in Japan depends on the number source and how it’s configured.
• Porting your Japanese business number is the safest option.
• “Verified Caller ID” is not reliable for JP domestic calls.

Now the details.

1. JP → JP outbound: does Dialora use Tokyo edge / domestic routing?

Yes — when using a Japanese number that is provisioned correctly, Dialora routes JP → JP calls domestically via Japan (Tokyo) voice edges, not international gateways.

However, this is number-dependent, not just account-dependent.

Caller ID preservation in Japan requires:
• A Japanese-originating number
• Domestic SIP routing inside Japan
• Compliance with Japanese telecom rules (CLI validation)

If any leg goes international, caller ID can be dropped or replaced — exactly as Twilio warns.

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2. Dialora numbers vs your own Twilio number

Dialora-provided Japanese numbers
• If the number is JP-local (03, 06, 050, etc.) and fully KYC-approved
• And is used for JP → JP calls
➡ Caller ID is preserved

Your own Twilio number / subaccount
• Works only if:
• The number is a Japanese domestic number
• It is routed via Japan edge
• It is not using international termination
• If the number is just “verified caller ID” (not owned/ported), caller ID may be stripped

So the behavior is the same for both — the number and routing matter more than the platform.

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3. Using your existing Japanese business number as outbound Caller ID

Strong recommendation: PORT the number.

In Japan:
• Ported numbers → stable caller ID
• Verified caller ID → unreliable / often stripped

Why:
• Japanese carriers expect ownership + domestic routing
• “Verified” IDs do not satisfy domestic CLI validation rules

If this is a customer-facing business line, porting is the only production-grade solution.

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4. If Caller ID stripping occurs — what’s the workaround?

Here are the only reliable options:

Option A (Best)

Port your Japanese business number into Dialora/Telnyx/Twilio
→ Guaranteed domestic routing
→ Caller ID preserved

Option B

Use a Dialora-provided JP number for outbound calls
→ Display that number consistently
→ Forward inbound calls to your main line if needed

Option C (Not recommended for production)

Use verified caller ID
→ May work sometimes
→ Will fail silently depending on carrier

There is no software-only fix if a call is being routed internationally — this is a carrier-level rule in Japan.

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Important reality check (being transparent)

Japan, Korea, and a few EU countries are carrier-regulated markets.
No AI platform — Dialora, Twilio, Telnyx, or anyone else — can override:
• Domestic routing rules
• CLI validation
• Carrier enforcement

What we can do (and do correctly):
• Ensure Japan domestic routing when possible
• Advise on the correct number strategy
• Help you port numbers cleanly
• Avoid configurations that cause silent CID drops

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Next step (recommended)

If this is mission-critical:
• Email [email protected]
• Subject: Japan Caller ID – Domestic Routing
• Include:
• Whether you plan to port a number
• Number type (03 / 050 / toll-free)
• Dialora number vs your own

We’ll confirm the routing path before you go live.

You’re asking the right questions — Japan is one of those markets where getting this right upfront saves weeks of frustration later.