Using one Twilio number and TaskRouter vs multiple numbers (flow and limits)

Question

I need to build a call center, from where agents needs to call the customers and customers needs to be able to call the agents. I am having doubts if I should have one Twilio phone number (for the call center) and then to instruct the incoming calls with the Twilio TaskRouter (to create a separate Worker for each agent) OR if each agent should have separate Twilio phone number. I am considering this from scalability point of view and the limits that Twilio has.

I saw a comment here that says:

For now reduce your batch size to 1 so that you only make 1 request at a time to the Twilio API.

The call center that I am considering to build, will have very high usage with a lot of agents making / receiving calls at the same time. It will also support SMS messages and conference calls (warm transfers).

So I have concern that I eventually may face limit issues if I use one Twilio number for the call center with the TaskRouter and agents as workers. Based on the Twilio docs, I was not able to figure out, what is the limit that I will have in the system for this case.

On the other hand, if I use separate Twilio numbers for each agent, will this be a better option to reduce the eventual limits I may face? I guess that limits are per Twilio number and the system will be able to scale better if I use separate phone numbers?

But in such a case, if each agent is having separate Twilio number, can I still use the TaskRouter and workers?

Answer 1

You don't need to have a number per worker (agent). There is no constraint for handling incoming or making outbound calls over a Twilio number. One thing to be aware of is for outbound calling, the terminating carrier may place analytics scoring on the CallerID, and thus based on calling patterns, may flag your number to dialed parties as SPAM/SCAM likely (you see this on calls to mobile carriers at times). If you are using one number, answer rate can suffer if it is marked.

Recommendations and Best Practices for Maintaining a Positive Caller Reputation

If all agents use the same outbound call, you will need to arrive at a way of routing the return calls back to the respective agent, maybe somehow capture this outbound activity in a datastore and when a inbound call comes in, use Twilio Studio to discover which agent places the outbound call (or pool of agents that can service that call) and send that in to Flex using Task Router attributes and Task Router logic to direct the task to the best worker.

The concurrency issue you quoted above is no longer an issue (1 concurrent API call a second). Every CPaaS provider has concurrency limits in place to protect their platform but not that low.

If you are making a larger volume of outbound calls (based on how many calls yo need to make over a period of time), you will need to work with Twilio to look at increasing your Calls Per Second (CPS) which defaults to 1 CPS. This impact how many concurrent calls you can place in a second, not the total number of concurrent calls you can have active at a time.

REST API: Best Practices

Twilio Flex powers large enterprise contact centers, so you shouldn't worry about capacity issues but I definitely suggest working with your Twilio Account Executive and Solution Engineer to make sure you account for all your requirements.