Resilient VoIP architecture on AWS is delivered by three types of providers, depending on what you are building. AWS Partner Network telephony specialists (AVOXI, Convergia, DrVoIP) implement Amazon Connect and CCaaS workloads.
AWS Premier and Advanced Tier consulting partners (Deloitte, CloudHesive, Mission Cloud, N-iX, Brainvire) handle broader cloud migrations that include voice components.
Specialist VoIP engineering firms (Ecosmob, ICT Innovations, Magic Technolabs) design and deploy custom telephony stacks, FreeSWITCH, Kamailio, and OpenSIPS, on AWS infrastructure with multi-AZ and multi-region resilience patterns.
The right provider depends on whether you are deploying Amazon Connect, modernizing an existing telephony stack onto AWS, or building a new VoIP platform from open-source components.
Almost every project in this space falls into one of two paths, and the partners that fit each path are different. Below is how to tell which path you are on, who builds for each, and what resilience actually means in both cases.
Which Path Are You On?
One question separates them. Are you deploying Amazon Connect (AWS’s managed contact center service) or are you deploying your own telephony stack on AWS infrastructure?
If the answer is Amazon Connect, you’re on Path A. The work is integration, custom routing, IVR design, CRM connections, and number management. AWS owns the underlying media plane.
If the answer is your own stack (FreeSWITCH, Asterisk, Kamailio, OpenSIPS, or commercial softswitch), you’re on Path B. The work is infrastructure design across Availability Zones, SIP routing, RTP networking inside Kubernetes or EC2, and the operational practices that keep voice running when AWS components fail.
Path A: You’re Deploying Amazon Connect
Who builds this
AWS Service Delivery Partners with Amazon Connect specialization are the natural fit. The named firms doing this work most visibly are AVOXI (global SIP trunking integrated with Connect, voice coverage in 60+ countries), Convergia (SIP trunking and integrations for the Americas region), DrVoIP (Connect contact center implementations and IP telephony architecture), and the broader pool of AWS Premier consulting partners like CloudHesive and Mission Cloud that include Amazon Connect in their AWS practice.
What “resilient” means here
Amazon Connect itself is multi-AZ and multi-region by design. Per AWS’s own architecture documentation, the service spreads across multiple Availability Zones with multiple telephony provider links into each AZ. Your job is not to build resilience into Connect; AWS built that. Your job is to build resilience into everything around Connect: your CRM integrations, your IVR logic, your number routing, your data flows, and your failover playbook if a region itself goes down.
What to ask the partner
Ask three questions in the first call. First, what’s their pattern for multi-region failover of Connect contact flows. Second, how do they handle DID number portability between regions. Third, where does their integration code run (Lambda, ECS, on-prem), and what’s the failover behavior of that code. Generic AWS partners often answer well on Lambda and ECS but stumble on the number-level questions.
Path B: You’re Deploying Your Own Telephony Stack on AWS
Who builds this
Specialist VoIP engineering firms. The pool is small because the skill set sits at the intersection of two domains that almost never combine in one team: deep SIP and RTP engineering, and cloud-native AWS architecture.
Ecosmob operates in this space, with VoIP infrastructure migration services specifically for AWS-based telephony deployments and DevOps consulting for the operational layer. ICT Innovations and Magic Technolabs work the same intersection. Generic AWS Premier partners can sometimes deliver this when they have a dedicated telephony cell internally, but the talent is concentrated, and you want that cell, not the generic one.
What “resilient” means here
This is where most architects get it wrong. AWS gives you the building blocks, but voice does not survive lift-and-shift onto generic cloud infrastructure. Resilience for a telephony stack on AWS requires several specific design decisions, drawn directly from AWS’s own real-time communication architecture guidance:
Multi-AZ deployment with SIP-aware load balancing. SBCs and PBX nodes deployed across at least two Availability Zones in each region. Failover between AZs works by IP reassignment for public IPs or by SIP client re-registration with the backup SBC for private IPs.
Availability Zone affinity for media. RTP media should stay within one AZ when possible, because cross-AZ traffic adds latency and cost. AWS specifically recommends EC2 placement groups within each AZ for the highest-bandwidth, lowest-latency intra-AZ paths.
Multi-region SIP routing for catastrophic failover. Deploying SIP infrastructure across multiple AWS regions allows traffic engineering at the call-control layer, so a call from one geography to another can pick the best route rather than going through the default AWS backbone.
RTP inside Kubernetes is its own problem. If you’re running FreeSWITCH or Asterisk on EKS, standard Kubernetes networking will silently break RTP media flow. Solutions involve Multus CNI for direct pod network interfaces or hostNetwork patterns at the SIP edge. A partner that hasn’t shipped this in production will not know.
What to ask the partner
Ask the same three questions everyone asks AWS partners (multi-AZ patterns, IaC approach, observability stack), then ask the four that filter for telephony depth: How do you handle RTP NAT traversal across AZs? Which SBC do you deploy and why? How do you monitor SIP transaction success rates and RTP packet loss per call? What’s your runbook for an AZ failure during peak call volume?
Partners who have done this answer in specifics. Partners who haven’t reach for terms like “AWS Well-Architected” without ever naming a SIP-level pattern.
