VoIP/SIP Engineer for AI Voice Integration

@farooqtahir2013

Having spent over a decade as a Network, Cybersecurity, VoIP and System Engineer, I am not only well-versed in the technical aspects of the job but also have a deep understanding of choosing the best tools for each unique project. The breadth of my experience spans from small setups to enterprise-level projects and I always work according to industry best practices. My proficiency with vendors such as Asterisk PBX, FreePBX, 3CX, Vodia and Cisco CUCM,CME equip me well to handle the scale and complexity of your task. With me as your VoIP/SBC architect, you can expect an unwavering commitment to ensuring that your telephony architecture is not only functional but scalable and secure. My expertise in Session Border Controllers (SBC), SIP trunking and Carrier Integrations, designing multi-tenant voice architectures are particularly relevant to the infrastructure you seek to build. Just like how you've already integrated with Eleven Labs and Retell AI, I am adept at understanding and working with various AI voice platforms. This blend of skills is crucial for leveraging both the voice integration challenge you face now as well as any future requirements that may come along as your platform scales up. Choose me for a comprehensive solution design based on deep familiarity with similar contexts plus resilience when it comes to trouble-shooting challenging scenarios.

@abusayed2004

I can solve your outbound voice call call problem, open chat for detailed discussion. I already build solutions with elevenlab and deepgram using asterisk.

@Herculesz

Hi I can review and optimize your VoIP/SIP architecture for inbound and outbound AI calling across Analog, SIP Trunk, PBX, Public IP, and CGNAT environments. The main technical issue appears to be outbound call reliability behind NAT/CGNAT, where SIP signaling, RTP media paths, contact headers, registration behavior, and carrier routing can break differently per network. My solution is to design a scalable SBC-centered architecture with proper NAT traversal, RTP anchoring, TLS/SRTP support, SIP trunk routing, failover, logging, and tenant-level isolation. I have hands-on experience with Asterisk, FreePBX, 3CX, Grandstream UCM/HT gateways, Yeastar, SIP trunks, PBX integrations, RTP troubleshooting, and carrier interconnects. I can also help align ElevenLabs and Retell AI call flows with your telephony layer so inbound and outbound sessions remain stable under concurrent load. For scaling to 100 concurrent calls and future multi-tenant growth, I would define SBC placement, HA design, media relay strategy, trunk capacity, monitoring, and operational best practices. This approach will give your platform a reliable foundation for customers connecting existing numbers from analog lines, mobile routes, PRI/E1, PBX systems, or SIP carriers. Thanks, Hercules

@C0RETECHIES

Hello, I see you've successfully integrated the AI voice layer (Retell/ElevenLabs) but need a carrier-grade telephony core to connect it to the real world. The key is building a scalable "front door" that normalizes inbound traffic from any customer setup (PBX, gateways, trunks) and resolves the outbound NAT/CGNAT issues for reliable call origination. Technical approach: We would design this around a centralized SBC like Kamailio with RTPEngine. This provides a multi-tenant platform to handle SIP registration, topology hiding, and critical NAT traversal (symmetric RTP). It becomes the single, secure interconnect between all customer endpoints and your AI platform. Core modules: A central SBC routing engine for call control and security. Standardized onboarding profiles for common customer equipment (Grandstream, Yeastar). Carrier trunking module for DID management. A media proxy for secure RTP stream handling to/from Retell AI. Relevant systems: We have hands-on experience with this exact domain, having built call management software on FreeSWITCH. We have also architected several outbound AI calling platforms, tackling similar real-world connectivity and call setup challenges. I can help architect and implement this solution. Let's discuss the specifics. Regards, Rohit

@kamran2012

Interesting project, I will tackle the outbound call failures under CGNAT and NAT — diagnosing SIP ALG interference, symmetric RTP issues, and far-end NAT traversal — then design the multi-tenant telephony architecture to support your 100 concurrent call target across Analog, SIP Trunk, PRI/E1, and PBX connections. For outbound under CGNAT, I will deploy an SBC layer that handles far-end NAT keepalives and forces symmetric RTP, ensuring media flows reliably regardless of the customer's network topology. This also gives you a single enforcement point for TLS/SRTP and tenant isolation as you scale to 1000 customers. Questions: 1) Are you running Asterisk/FreePBX or Grandstream UCM as your core PBX today? 2) For the SBC, do you have a preferred platform, or is selecting one part of this engagement? Looking forward to discussing further. Best regards, Kamran

@mohjib092

Hi! Your requirements align well with my experience in SIP/VoIP infrastructure, PBX systems, carrier integrations, NAT/CGNAT troubleshooting, and scalable telephony architectures. I can review the current ElevenLabs/Retell AI deployment, identify the outbound calling limitations, and design a robust multi-tenant architecture capable of supporting your target scale with high availability and future growth in mind. Best Regards

@trm66614

I have significant experience with VoIP and SIP technologies and can help optimize your AI voice integration. With integrations already set with ElevenLabs and Retell AI, I can assess your outbound call requirements specifically for Public IP connections. My knowledge in designing scalable telephony architectures will ensure seamless integration of existing phone numbers. I am experienced with Session Border Controllers and NAT troubleshooting, critical for optimizing both inbound and outbound traffic in your setup. I understand the importance of High Availability in telephony environments and will implement best practices for your infrastructure to support approximately 1000 potential customers with 100 concurrent calls. What specific challenges have you faced with the current system that you want me to address? Do you have a timeline for implementing these optimizations? How do you measure success with your AI voice platform? What current technologies are you using for SIP trunking and carrier integrations? This project sounds exciting, and I believe I can provide significant value to your team.

@huzaifa306

Hi, I have more than 3 years of experience building automation systems, AI powered workflows, voice automation solutions, and integrations across different industries. I can help review your current setup, identify the outbound calling limitations, and design a reliable, scalable telephony architecture that supports AI voice integrations, high call volumes, and long term growth.

@ahmedsud

Hello, I can assist with the VoIP/SIP architecture review, outbound calling assessment, and scalable AI voice telephony setup for your platform. My approach will be: Review your existing AI voice integration with ElevenLabs / Retell AI and current inbound/outbound call flow. Analyze why outbound calls work only on Public IP and identify issues related to NAT, CGNAT, RTP, SIP signaling, firewall, or carrier routing. Design a scalable architecture for connecting customer numbers through Analog gateways, SIP trunks, PBX, PRI/E1, mobile, and SBC-based routing. Recommend the right SBC/PBX model using tools such as Asterisk, FreePBX, 3CX, Grandstream UCM/HT, Yeastar, or dedicated SBCs. Implement and test inbound/outbound calling with proper SIP trunking, RTP handling, security, and failover planning. Provide best practices for supporting around 100 concurrent calls initially and scaling toward a multi-tenant customer environment. I have strong experience with Linux server management, SIP/VoIP troubleshooting, PBX systems, NAT/CGNAT issues, SIP trunk integrations, RTP debugging, and scalable telecom architecture planning. Estimated time: Initial assessment: 1–2 days Architecture design and recommendations: 2–4 days Hands-on implementation/support: depending on the existing setup and carrier/PBX requirements. I am available to review your current setup and help build a reliable, scalable AI voice telephony architecture.

@amadorjay

Hi, I can develop a scalable telephony architecture that connects various phone systems to your AI voice platform. The best solution is to optimize your existing outbound call capabilities while ensuring robust inbound call handling across all environments, including NAT and CGNAT. I’m comfortable with VoIP technologies like SIP, PBX, and SBCs, as well as platforms such as Asterisk and FreePBX. I’ll keep the solution reliable with a focus on high availability and performance optimization. Deliverables will include a detailed architecture review, solution design documentation, and implementation support to ensure smooth integration with your existing systems. Looking forward to collaborating on this project.

@ketanjadhav8109

Hello, I am very interested in this opportunity. I have 17+ years of experience in VoIP, SIP, and telecom solutions and 5+ years of experience building custom AI Voice Agents. I have extensive hands-on expertise designing, deploying, and optimizing scalable telephony infrastructures for AI-powered platforms. My experience includes Asterisk, FreePBX, 3CX, Grandstream UCM, Yeastar, SBCs, SIP Trunks, PRI/E1, Analog Gateways, and carrier integrations. I have also integrated AI voice platforms such as ElevenLabs, Retell AI, Vapi, and OpenAI Realtime for production environments. Your outbound calling challenges across Public IP, NAT, and CGNAT environments are areas I have solved multiple times. I can assess your existing infrastructure, troubleshoot SIP signaling, RTP flows, TLS/SRTP, firewall traversal, and optimize call routing for reliable performance. For your 1,000-customer environment and 100 concurrent calls requirement, I can design a secure, scalable, multi-tenant, and highly available telephony architecture that supports both inbound and outbound AI calling while allowing customers to connect their existing phone systems seamlessly. I would be happy to review your current setup and help build a long-term, production-ready solution. Best regards, Ketan Jadhav 17+ Years in VoIP/Telephony | 5+ Years in AI Voice Agent Development

@rafa099

Hello, Your project aligns closely with the type of AI voice infrastructure currently being adopted for scalable customer-facing voice automation. I understand that inbound calling is already operational across Analog, SIP, Public IP and CGNAT environments, while outbound calling remains limited to Public IP deployments. The key challenge appears to be designing a robust architecture that supports reliable inbound and outbound AI calling regardless of customer network topology. My approach would focus on: • Reviewing the current Retell AI and ElevenLabs integrations • Analysing SIP signalling and RTP media flow across NAT/CGNAT environments • Evaluating SBC requirements for secure multi-tenant deployments • Designing a scalable architecture capable of supporting 100+ concurrent calls initially and future growth • Defining best practices for SIP trunk integration, TLS/SRTP security and high availability • Supporting implementation, testing and optimisation Experience includes AI voice workflows, SIP-based communications infrastructure, Linux environments and scalable system architecture design. All recommendations will be documented with deployment guidance and operational considerations for future expansion. I would be happy to discuss your current topology, carrier setup and outbound call flow challenges in more detail. Kind regards

@techsty2014

Interesting project, We will diagnose your outbound call failures across NAT and CGNAT environments, then design the multi-tenant telephony architecture to support your 1,000 customer target. For outbound behind CGNAT, the fix typically involves placing an SBC (like Obt or Obt) at the edge to anchor SIP registration and handle symmetric RTP. This resolves one-way audio and registration timeouts without requiring public IPs on every endpoint. A couple of quick things to confirm: 1) Which SBC or proxy (if any) sits between your Grandstream gateways and Retell AI today? 2) Are your carrier SIP trunks registration based or IP authenticated? The number quoted here is a starting estimate. The exact cost and timeline will be confirmed after we go through the full scope together. Send me a message and we can go over the details. Best regards, Faizan

@johnc150

✅Hi, How are you? I can support you in stabilizing and scaling your AI VoIP architecture, especially focusing on the outbound call limitations you’re currently experiencing. My approach would start with a deep dive into your SIP routing path, NAT traversal setup, and SBC configuration to identify why outbound calls fail on CGNAT/private network scenarios while inbound calls remain stable. From there, I would help design a scalable multi-tenant telephony architecture that properly separates signaling and media layers, ensuring reliable SIP trunking across Analog, PBX, and cloud environments. I also have experience working with Asterisk/FreePBX-style systems and AI voice integrations, so I can help align your ElevenLabs and Retell AI flow with a robust SIP infrastructure that supports high concurrency, TLS/SRTP security, and carrier-grade reliability. Best Regard, John

@SherozKhalid9

Hi I’m an experienced VoIP/SIP engineer with deep expertise in SBCs, SIP trunking, PBX platforms (Asterisk, FreePBX, 3CX), and gateways (Grandstream, Yeastar). I’ve designed scalable, multi-tenant telephony architectures with HA and RTP/TLS/SRTP best practices for carrier-grade deployments. I’ll review your current ElevenLabs and Retell AI integrations and optimize outbound call flows across Public IP, NAT, and CGNAT environments. I’ll assess SIP trunk and carrier integrations, recommend SBC placement/configuration, and implement NAT traversal and media anchoring solutions. I’ll provide a detailed architecture design, capacity planning for 100 concurrent calls (scalable to your growth), and failover strategies. I’ll deliver hands-on implementation support, testing (SIP OPTIONS, RTP streams), and monitoring recommendations for production readiness. I’m comfortable working with analog gateways, PRI/E1, mobile termination, and PBX migrations to your AI voice platform. My approach focuses on reliability, security (TLS/SRTP), and minimizing call setup failures and media issues. I can start with an architecture review and a prioritized implementation plan within your timeline and budget. Looking forward to helping you build a robust, scalable AI telephony platform. best regard khalid

@mubeenm5026

As a seasoned VoIP/SBC architect and founder of Web Crest, I'm confident that I bring the comprehensive skill set necessary to not only fulfill your project requirements but exceed expectations. My team and I have extensive experience in the areas crucial to this project, such as SIP, VoIP, PBX, SBC technologies, session border controllers (SBC), carrier integrations, AI voice platforms like ElevenLabs and Retell AI, to name just a few. With a successful history of integrating AI personal assistant platforms into telephony infrastructures across multiple environments, including NAT and CGNAT ones like you're dealing with, our proficiency in troubleshooting the complexities of these systems is unmatched. Additionally, my team's ability to design scalable multi-tenant voice architectures that prioritize high availability (HA) environments lays the perfect foundation for your needs. Working with us means leveraging well-rounded professionals committed to delivering secure, future-ready, and high-performing solutions tailored to your exact necessities. We value transparent communication with timely responses and always prioritize providing long-term technical support; we want to be there for you throughout the lifespan of your platform. Let's collaborate on your project and create something truly exceptional together.

@krupnovdenis

Hello! We can help design and implement a scalable telephony setup for your AI voice platform. 1. Which part needs to be improved first: outbound calls, scaling, or NAT/CGNAT handling? 2. Do you already have a target architecture or preferred SBC/PBX setup? — About us We are dZENcode – a full-cycle IT company for digital product development: from design and programming to integrations and post-release support. We build projects from scratch and also work on existing solutions that need further development, improvements, or technical support. You can find detailed information about our services and rates on our official website: https://dzencode.com. Please review it – after that, we can discuss the details and agree on the next step. ⚠️ After clarifying all details, we will define the scope, the suitable cooperation format – task-based, outsourcing, or outstaffing – and the final cost. Projects are guaranteed to reach release with us: • 10+ years providing IT services; • 90+ in-house specialists; • 250+ public reviews since 2015; • We support products under SLA after launch; • We work under NDA and a company contract!

@mobasherreza10

With over a decade of experience in VoIP/SBC technologies and a solid track record of successful integrations with platforms like ElevenLabs and Retell AI, I am confident that I have the skillset necessary to optimize your outbound calling and create a scalable telephony architecture that can fully leverage your AI voice platform. Having worked extensively with Grandstream UCM, Yeastar, 3CX, Asterisk, FreePBX and mastered the uses of Session Border Controllers (SBC) and SIP Trunking, I understand the unique challenges faced when connecting various phone systems—a skill that will be vital when integrating existing phone numbers from Analog to SIP Trunk and beyond.

@Mazhar2976

Hi there, ​I understand you are looking for an experienced VoIP/SIP engineer to optimize your AI voice integration platform. I have a strong background in telephony architecture and can help you resolve the outbound calling issues you are facing with your current Public IP setup. ​My core expertise aligns with your requirements: ​Infrastructure: Deep experience with Asterisk, FreePBX, and SIP trunking architectures. ​Troubleshooting: Expert level knowledge in NAT, CGNAT, and TLS/SRTP environments to ensure reliable outbound connectivity. ​Scalability: I have designed multi-tenant voice architectures and can support your target of 100+ concurrent calls effectively. ​AI Integration: Familiarity with integrating ElevenLabs and Retell AI into existing telephony flows. ​I am ready to review your current architecture and provide a roadmap for the scalability and optimization you need. Let’s discuss how I can help stabilize your platform for your 1000+ potential customers. ​Best regards,