Twilio / Retell Number & SIP Setup

@rajat07me

Your issue sounds less like a voice-AI problem and more like a Twilio routing layer mismatch: the number exists, but the call is not being handed off correctly into the SIP path that should reach Retell/Manas. In jobs like this, the fastest route is usually to trace the call path step by step—number config, trunk origination/termination, auth, codec, and routing targets—until we find the break and make test calls both ways. I’ve worked on telephony setups where Twilio numbers, SIP trunking, and external voice/IVR systems were all individually “fine” but one small trunk or credential setting stopped the entire flow. These are usually solved by careful Twilio-side validation rather than guesswork, and I can also leave you with a clean summary of what changed so you can repeat it for future client deployments. - Is the AU number already purchased in Twilio, or do you want me to source and configure it from scratch? - Are you using Twilio Elastic SIP Trunking specifically, or a SIP Domain / programmable voice route in front of Retell? - Do you already have the Retell SIP URI and preferred codec settings ready for testing?

@inventivedesigne

The issue sounds like the Twilio routing layer rather than the Manas/Retell conversation logic, so I’d trace the call path from the Australian Twilio number through SIP trunking to the Retell endpoint. I can handle the Twilio number configuration, inbound/outbound routing, SIP authentication, termination/origination settings, codec configuration, and call-flow testing. I’ll also check the points where the call could be getting dropped before reaching the AI pipeline rather than changing the working Manas/Retell setup unnecessarily. Once inbound and outbound calls are working reliably, I’ll document the Twilio/SIP configuration and testing steps so you can reproduce the setup for future clients. If you share the current Twilio setup and Retell SIP details, I can start by tracing the existing call path and identifying where it breaks. Hafiz S

@extreamcode

Hi there, The hidden failure point here is likely not the AI logic, it is the handoff between Twilio’s number configuration, SIP trunk routing, authentication, and Retell’s expected call path. I can trace that full chain and get inbound and outbound Australian calls reliably reaching your Manas AI pipeline. I’ll audit the Twilio number settings, SIP trunk origination and termination, credentials, routing, codecs, and webhook/API Integration touchpoints, then validate call flow and audio quality end to end. My PHP and API experience helps me document the configuration clearly, while Artificial Intelligence voice workflows keep the debugging focused on the actual SaaS behavior rather than isolated settings. I’ve shared an initial estimate based on your description, and once we go over a few technical or functional details, I’ll confirm the exact cost and delivery schedule. We can review the current Twilio and Retell configuration first, then I’ll implement the corrections and provide a concise replication guide. Playfully technical question: is Retell expecting a standard SIP URI with credential-based auth, or a Twilio Elastic SIP Trunk termination target already provisioned? Thanks, Asad Looking forward to your reply so we can finalize the exact plan.

@Synet

Hi, That silent call drop usually happens when Twilio tries to route the inbound webhook to the wrong endpoint or the SIP trunk credentials and termination URIs do not match what Retell expects to hear. I will open up your Twilio console right now and check the active numbers, webhook URLs, and the core SIP termination settings to find where the signal is getting lost. Once I spot the mismatch, I will configure a fresh Australian phone number, build the proper SIP trunk, and map the correct codecs so the audio stream hits Retell cleanly in both directions. While fixing this routing, I will also set up geo permissions for your numbers so you do not hit unexpected carrier blocks on outbound test calls later. After the phone rings and the AI answers smoothly, I will send you a short list of the exact steps and setting names I touched so you can repeat the process for your next users. Which region in Australia are you buying these numbers in, and are you using TLS or plain UDP for the trunk transport? Best, Salma Noreen

@starttechno

I’ll trace why the Australian Twilio number never reaches the Manas AI/Retell pipeline, starting with the number’s Voice webhook/SIP settings, trunk termination/origination rules, and the exact destination expected by Retell. I’ll correct or create the SIP trunk, configure authentication, routing, codecs, and caller-ID behavior, then verify both inbound and outbound call paths so audio reaches the AI layer cleanly. Within 2 days, you’ll receive a working Twilio number/SIP setup plus a concise configuration note covering each changed setting and how to repeat it for future clients. I’ll also distinguish any Twilio or Retell account limitation from a configuration issue rather than masking it with trial-and-error changes. Is the Retell SIP destination and authentication detail already available in your account, or should I first identify the required values from the current setup? Muhammad Saad

@ranjika08

The fact that calls never reach the Manas/Retell layer usually points to a Twilio config gap before the AI stack ever gets a chance to respond. I’d approach this by checking the Australian number assignment, inbound voice handling, SIP trunk auth and routing, then running controlled test calls to confirm clean two-way audio without delay or codec issues. I’ve handled setup and troubleshooting work where telephony providers, SIP trunks, and downstream voice systems were connected in theory but not in practice because of one routing rule, ACL, credential, or termination detail. For this kind of project, concise debugging beats a long process, and I can document the final working configuration in a short repeatable handoff note. - Is outbound calling also meant to present the same Australian Twilio number as caller ID? - Do you want credential-based auth, IP-based auth, or whichever is best supported by your current Retell side? - If you have any existing Twilio call logs or test attempts, can you share whether the calls fail before trunk handoff or after it?

@DeveloperStation

Hi, I've shipped multiple Twilio integrations, including SMS flows, REST API wiring, and voice routing across Laravel and CodeIgniter apps, all with 5 star reviews. On a silent-failure like yours, where calls never reach Manas/Retell with no error, I'd first check whether the number's Voice configuration is pointing at the SIP trunk versus a webhook, then verify the Origination URI and termination SIP URI match what Retell expects. Codec mismatch is the usual cause of audio distortion once the path connects, so I'd lock that early. Quick question: is the trunk Elastic SIP or a programmable voice setup? That changes where the break likely sits. I'll document every change so you can replicate it per client. I can start on a first milestone so you only release once the number rings through. Adil

@AITSoft

Hi, I understand you need an Australian Twilio number configured for reliable inbound and outbound calls, then connected through SIP so audio reaches the Manas AI and Retell pipeline without delays or distortion. I’ll check the number configuration, voice webhooks, SIP trunk termination and origination settings, authentication, routing, codecs, and any required API Integration points. I’ll test both call directions, trace where the call stops, and fix the settings rather than guessing. After it works, I’ll provide a short explanation of the changes so you can repeat the setup for future Australian clients. I have hands-on experience with Twilio and SIP-based voice flows, including troubleshooting multi-layer routing issues where calls appear active but never reach the final voice service. Is Retell expecting a specific SIP domain, transport type, codec list, and authentication method for this trunk? Thanks,

@Joya1996

You already have the AI pieces in place, so this looks like a telephony handoff problem inside Twilio rather than a build-from-zero situation. The key is to validate the number setup, trunk direction, auth method, routing destination, and audio settings in the right order so we can get a real call reaching Retell reliably instead of chasing symptoms. I’ve worked on SIP and provider-side configurations where everything appeared connected but the live call path still failed because of a subtle misconfiguration in the voice flow. Once fixed, these setups are usually very stable, and I can give you a short walkthrough of the final structure so you can clone it across future Australian client numbers. - Is this for one tenant/client right now, or do you want the setup done in a reusable way for multiple future numbers? - Are there any specific codec preferences from Retell’s side that must be enforced? - Do you want a simple written handoff, or a short step-by-step checklist you can reuse internally?

@naminghn

Hi there, I noticed you're looking for help with configuring your Twilio Australian phone number and establishing a functional SIP trunk for your AI phone-answering system. I have substantial experience in setting up Twilio integrations and SIP configurations. My background includes ensuring seamless audio through correct routing, authentication, and codec settings, which aligns well with the requirements you’ve outlined. I'll set up the phone number and SIP trunk to ensure flawless inbound and outbound call functionality to your AI stack. Additionally, I’ll provide documentation detailing the changes made, so you can replicate this for future clients. Let’s get this working smoothly for your project. Regards, Ali

@efanntyo

Hi there, I understand you're facing challenges with configuring Twilio for your AI phone-answering SaaS. With extensive experience in integrating Twilio with SIP trunking, particularly for AI-driven voice systems, I’m well-equipped to assist you. In a past project, I successfully set up Twilio numbers and SIP trunks for a contact center solution, ensuring seamless integration with AI interfaces. This experience taught me the intricacies of Twilio's multi-layer configuration, which seems to be the stumbling block in your current setup. Here's how I plan to tackle your issue: First, I'll procure and configure a Twilio Australian phone number to ensure it's operational for both inbound and outbound calls. Then, I'll establish a SIP trunk with the correct authentication, routing, and codec settings to ensure that audio is transmitted to Retell without any issues. Finally, I'll provide a concise documentation or a brief walkthrough of the changes for your future reference. I'm committed to delivering a smooth flow of calls through your AI pipeline, leveraging my past experiences to troubleshoot and resolve any configuration issues efficiently. Looking forward to the opportunity to collaborate and get your system running flawlessly. Best Regards,

@denisSolution

Hi, I'm Denis, a full-stack developer who's set up Twilio voice infrastructure for AI pipelines before. I've solved the exact problem you're describing—calls dropping before reaching the AI layer—and it's usually a SIP trunk routing or codec mismatch issue. I understand you have Manas and Retell connected, but Twilio isn't bridging inbound calls into that pipeline. The number exists, but calls don't get through. This typically points to incorrect SIP trunk credentials, missing inbound request URLs in Twilio, or audio codec negotiation failing between Twilio and Retell's endpoint. I've configured Twilio SIP trunks for voice AI systems before. Success requires three aligned elements: the Australian number provisioned to the trunk, the trunk authenticated and routed correctly, and Retell's SIP endpoint configured with proper codec settings. My approach is straightforward. I'd audit your current setup—number status, trunk configuration, inbound request URL, and authentication. Then verify the SIP trunk routes calls to Retell, check codec negotiation, and test end-to-end with a real call. I'll document what changed and why, so you can repeat it for new clients without friction. The key issues are usually whether Twilio's request URL points to Retell's SIP ingestion endpoint and whether trunk credentials match what Retell expects. Often it's just a missing parameter or URL typo breaking the chain. I can start right away. Let's discuss the details. Thanks, Denis.

@artiboria

As an experienced website developer and eCommerce expert, I am well-versed in handling complex software integrations. Specifically, I have a proven track record of setting up voice AI and contact center solutions for businesses using Twilio and SIP trunking. My understanding of these technologies combined with my previous work experience will ensure that the Twilio number is not only acquired and configured correctly but also fully operational for both inbound and outbound calls. Moreover, I'm accustomed to creating as well as rectifying SIP trunks with precise adjustments for optimal audio quality. Given that, integrating Retell into the existing stack—managing appropriate authentication, routing, and codec settings—is within my purview. Further, I understand your need for documentation precision. No worries, with me you can be assured of receiving an explicit step-by-step guide or a walkthrough detailing all the changes made so that you can easily replicate it in future with absolute reliability. I’m confident that my skills, expertise and diligent work ethic will be indispensable in getting your project unstuck. With all that being said, let's get your Twilio numbers to flawlessly ring through your AI pipeline!

@adeelpirzada

Hi, I am Adeel. I built MyHeartLine, a voice AI platform that places and receives scheduled calls to elderly patients and routes the audio through a conversational AI layer, so I spend a lot of time inside exactly this kind of telephony to AI pipeline. Most times a call reaches Twilio but never gets to the AI layer, the break is in the SIP trunk's origination or termination URI, or a codec mismatch between Twilio and the AI endpoint. I would check the trunk config, the number's voice webhook, and confirm the codec Retell expects before touching anything else. I can do the first fix free, around two hours, so you can see the number actually ringing through before committing further. Which side is failing right now, inbound calls to the number, outbound calls from the AI, or both?

@codefusion53

Hi I can configure and troubleshoot the complete Twilio voice flow for your Australian AI phone system, including the Twilio number, SIP trunk, authentication, routing, codecs, and connection to Retell. I have experience with Twilio Voice, SIP, API integrations, call routing, and AI voice workflows. I would systematically trace the call path from the Australian number through Twilio and SIP to Retell/Manas, identify the configuration issue, and test both inbound and outbound calls until the pipeline works reliably. I can also document the exact Twilio and SIP settings so you can replicate the setup for future clients without having to troubleshoot it again. I will focus specifically on getting the call flow operational and can work directly with your existing Twilio and Retell configuration. Best, Justin

@lazarr4

Hello, I can set up a Twilio SIP trunk for your AI phone system and ensure calls flow smoothly to Manas AI without audio issues. I’ve configured a similar SIP trunk for a voice AI client—once we fixed a codec mismatch, latency dropped from 500ms to 120ms. I’d approach this by first verifying the Twilio number’s inbound/outbound settings, then setting up the SIP trunk with G.711 codec and proper authentication. The key will be ensuring Retell’s WebSocket URL matches Twilio’s trunk configuration exactly. This setup will let your AI handle calls reliably, reducing dropped connections and improving response times. I’ll document every change so you can replicate it for other clients. After the project, I’ll provide a checklist of common Twilio/SIP issues to avoid in the future. If this approach makes sense, I’d be happy to review your current setup and suggest the best next steps. Thanks, Lazar.

@istkhar5

Hello, I hope this message finds you well. Your project caught my attention as I have recently worked on a similar project involving setting up Twilio numbers and SIP trunking for a voice AI solution. I understand the importance of ensuring that calls flow seamlessly to and from the AI layer without any disruptions. I have experience in configuring Twilio Australian phone numbers and setting up SIP trunks with the correct authentication, routing, and codec settings to ensure optimal audio quality. I can provide you with a quick walkthrough or a concise document detailing the changes made for future reference. I believe my expertise in this area aligns well with the requirements of your project. I would love to discuss how I can assist you further. Please feel free to reach out for a call to discuss the project in more detail. Best regards, Mehreen

@temoberishvili

Hey! It sounds like you're building something really interesting with the AI phone-answering SaaS for Australian businesses. I see you're looking for help with Twilio, SIP setup, and API integration. With my solid background in PHP and experience with Twilio, I can help you streamline the voice assistance features you need. Let’s work together to make this a success! Looking forward to chatting more.

@longngoc2307

Hi, there. "TWILIO SIP TRUNK CONFIGURATION" - you need the Australian number to reliably reach the Manas/Retell AI pipeline. I would trace the call path from Twilio number to SIP trunk to Retell, checking routing, authentication, codecs and inbound/outbound call handling. I would test the complete flow and leave you a short setup note so the same configuration can be repeated for future clients. The key edge case is one-way audio or failed outbound routing even after inbound calls work, so I would verify both directions before handoff. Is the Retell SIP endpoint already provisioned, or should I configure the Retell-side connection as well? Looking forward to working with you.