A startup's application team is deploying a new multi-tier app to AWS. The app will run on Amazon EC2 instances in an Auto Scaling group behind a public Network Load Balancer (NLB) and must support both UDP and TCP traffic. Initially it will serve users in one geographic area, but the team plans to expand to multiple AWS Regions so deployments can be placed closer to end users. They want to control how much traffic each Region receives during phased rollouts of new versions, and they must minimize first-byte latency and jitter for users. How should the team design the network architecture to meet these requirements?

AWS Global Accelerator is the correct choice because it provides static IP addresses that act as a fixed entry point to your application, improving availability and performance by routing user traffic through the AWS global network. It supports both TCP and UDP protocols, which is a key requirement. The traffic dial feature allows for precise control over the percentage of traffic directed to each regional endpoint, facilitating phased rollouts. By routing traffic over the AWS backbone, Global Accelerator minimizes first-byte latency and jitter. CloudFront is primarily a content delivery network (CDN) for caching static and dynamic web content, and while it can improve latency for HTTP/S traffic, it doesn't natively support UDP and isn't designed for fine-grained traffic shifting between regional origins in the same way Global Accelerator is. S3 Transfer Acceleration is for accelerating uploads to S3 buckets, not for general application traffic routing.