SNS Destinations

Service Name:	Simple Notification Service (SNS)
ARN Format:	`arn:aws:sns:{region}:{account}:{name of topic}`
Style:	Async (Write)
Actions (required Permissions):	`sns:Publish` (also grants access to `sns:PublishBatch`)
Payload Format:	JSON Packet, one message per packet

Proxylity's integration with SNS writes batches of packets arriving at your listener as messages to your topic. Writing packets to SNS enables fan-out notification patterns for moderate to high rate workloads, allowing multiple subscribers to process the same UDP traffic independently.

Technical Details

UDP Gateway uses the sns:PublishBatch API to efficiently write packets to your topic. This batch API allows up to 10 messages to be published in a single API call, reducing costs and improving throughput when handling high packet rates.

Important: The sns:Publish permission implicitly grants access to sns:PublishBatch as well, so you only need to specify sns:Publish in your IAM policy. While UDP Gateway batches packets for efficient transmission to SNS, each SNS message contains exactly one packet. When your topic subscribers receive notifications, each message body will be a single JSON packet object, not an array. This design ensures that individual packets can be processed independently by each subscriber, supporting diverse processing patterns across multiple endpoints.

The message body contains the complete request packet with all metadata including source/destination addresses, arrival time, and the UDP payload data. Your topic subscribers can process these messages using Lambda subscriptions, SQS queue subscriptions, HTTP/HTTPS endpoints, email, SMS, or any other SNS-supported protocol.

Best Practices

Batching Configuration: Set your destination's batching count to a multiple of 10 (the SNS batch limit) for optimal cost efficiency. For example, values like 10, 20, 30, or 40 packets minimize API calls while maintaining low latency. Consider the 256KB total message size limit when configuring batch sizes for large packets.
Topic Type: Standard topics provide the highest throughput and support multiple subscription protocols. FIFO topics preserve packet ordering and guarantee exactly-once delivery to SQS FIFO subscribers, but have lower throughput limits.
Permissions: Ensure your IAM role has the sns:Publish permission, which provides access to both single and batch publish operations.
Message Attributes: SNS messages include standard attributes that can be used for subscription filtering, allowing selective delivery based on packet characteristics.