Hello everyone, if we integrate our SIP Trunk on 3CX over Twilio, how are the costs managed? I am not sure, because we would like to use our sip trunk to save costs, but don't we pay double then?

Hi there! 👋 I understand your concern about potentially paying double when integrating your SIP Trunk on 3CX via Twilio. Let me help clarify how the costs work in this setup. When you integrate a SIP Trunk on 3CX via Twilio, here's how the costs are typically managed: ## Cost Structure When using Twilio as a SIP bridge between 3CX and other services: - Twilio charges for inbound/outbound calls (approximately $0.02/min for inbound, toll-free calls) [according to billing examples](https://docs.vapi.ai/billing/examples) - Your existing SIP trunk provider will still charge their fees - If you're also using another platform (like Vapi), there may be additional platform fees ## Potential Double Charges Yes, there is potential for double charges in this setup: - When Twilio acts as an intermediary, you're essentially paying for both your SIP trunk and Twilio's services for routing the same calls - As noted in [cost routing documentation](https://docs.vapi.ai/billing/cost-routing), charges for inbound/outbound phone calling will always end up where the phone number was provisioned - The total cost per call becomes the combination of platform fees and telephony charges from different providers ## Cost-Saving Strategies To avoid double charges and optimize costs: 1. **Use BYOC (Bring Your Own Carrier)**: Leverage your existing telephony infrastructure to minimize costs [as mentioned in user discussions](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1333747605628391434) 2. **Consider Alternatives**: Some users have found that using Asterisk instead of Twilio can lower costs significantly (up to 1/10th of Twilio's costs in some regions) 3. **Understand the Complete Cost Structure**: Check billing details from all providers involved to get a clear picture of your total costs 4. **Use Web Calls When Possible**: Web calls don't incur per-minute telephony costs, unlike phone calls

When integrating a SIP Trunk with 3CX via Twilio, there are several cost components to consider: 1. Your existing SIP Trunk costs 2. Twilio's fees for routing calls 3. 3CX licensing costs The cost structure depends on how you configure the integration. You have options to minimize redundant costs. When you connect your SIP Trunk to 3CX through Twilio, here's how the costs typically work: - **SIP Trunk Provider Costs**: You'll continue paying your SIP Trunk provider for the trunk itself and any associated minutes/services. - **Twilio Costs**: You'll pay Twilio for: - SIP interface usage (typically a small per-minute fee) - Any additional Twilio services you use (SMS, transcription, etc.) - **Traffic Flow Options**: 1. **Direct Integration**: You can configure 3CX to connect directly to your SIP Trunk provider for outbound calls, bypassing Twilio for those calls to avoid double fees. 2. **Selective Routing**: Route only specific call types through Twilio (like those needing special features) while sending standard calls directly through your SIP Trunk. - **Cost Optimization Strategies**: - Use Twilio only for specialized features your SIP Trunk doesn't provide - Configure call routing rules in 3CX to use the most cost-effective path for each call type - Negotiate volume-based discounts with both your SIP provider and Twilio