How does Bandwidth message queuing work?Follow
As Bandwidth receives SMS or MMS message requests that exceed your rate limit settings, these requests are queued for delivery. Rate Limit settings are relative to the number of sent segments, not messages (i.e., a 5-segment message is equal to 5 messages, not 1 message).
For HTTP, by default Bandwidth queues messages (segments) internally to be sent out. The default queue depth is a 15-minute queue across your entire account. The queue depth can be increased up to 4 hours as needed – please reach out to your account manager for queue depth increases. The number of messages (segments) in the queue will depend on your account-wide dequeue rate also known as your MPS (messages per second).Note: The queue size (15 minutes (900 seconds) up to 4 hours (14,400 seconds)) is across the entire account, and not per phone number.
You may send the message (segment) requests to Bandwidth at a high rate until your queue depth exceeds your dequeue limit x queue size (15 minutes to 4 hours depending on your individual settings). For example:
On HTTP, in the above example, where the dequeue rate limit is 5MPS, if you sent Bandwidth SMS requests at 100MPS for greater than 45 seconds, you would receive a rate limit error because you've exceeded the 15-minute queue depth when Bandwidth is dequeuing your messages (segments) to send at a rate of 5MPS.