Proxy Limits

Each service can have a maximum of 5000 Reserved numbers and 500 dynamic/non-reserved numbers.

We recommend, but do not enforce, a limit of 100 participants associated with a given number in active sessions at any given time. See https://www.twilio.com/docs/proxy/phone-numbers-needed for more information on proxy number management.

Limits of this type will impact the number of simultaneous actions that can be performed within a Service Instance.

RPS is the guaranteed Requests Per Second against a given endpoint that a Service instance will support. All Service instances have a baseline of 30 RPS per endpoint. Proxy will allow short bursts above the baseline RPS - up to 5x the baseline. If the bursts become sustained throughput, the Service will start rejecting requests.

The request limit is based on the average request rate in 5s sliding window. For example, for 30 req/s limit we allow bursts up to 150 req/s. After this, your application client request logic needs to wait until the average goes below the threshold to make any query requests again against that endpoint.

Requests that go over the RPS threshold are rejected with HTTP status code 429 Too Many Requests.

For reliable handling of short-term bursts of requests towards the Proxy REST API, please make sure your backend application implements a retry logic. When your application receives HTTP status code 429 back from the Proxy service, it should repeat the request several times, using a good exponential back-off algorithm like the one advocated by Amazon.

Limits for user provided data in UTF-8 characters. If a payload limit is specified in bytes, we assume that the data is serialized using UTF-8 encoding where each character (e.g. emoticon) may take more than one byte.