Maximum concurrent call limit in Asterisk

Hi guys,

I want to know the maximum number of concurrent calls handled by Asterisk.

I know that it can be configured by using “maxcalls” parameter in asterisk.conf. But don’t know the maximum value for that parameter. So in spite of enough memory configurations, can anyone tell me the maximum call limit value for both audio and video calls.


There’s no hard-coded value. The practical limit will depend on your hardware, your specific use cases, etc. Doing things like transcoding or large conference bridges will obviously take more CPU than not. Doing call recordings will take more I/O than not.

At some point (likely above the “hundreds of calls”) point, you’ll start running into CPU or disk I/O limitations – but again, that depends on your hardware and your use cases. I’ve seen hardware successfully run thousands of calls in some cases, and fall over with a couple dozens in others, simply based on the hardware and the specific uses of Asterisk.


The magic number may depend on your business model.

Suppose you do build some unicorn host that can handle x,000,000 simultaneous calls. How will your boss react when it crashes and you go from hero to zero?

How will you handle hardware maintenance and software upgrades?

How will you roll out bug fixes? How will you roll back bad bug fixes?

Recovering from an issue that affects 10% of your business is easier than 100%.

How will you grow your capacity when you need 20% more but can’t afford 100% more and haven’t developed an architecture or infrastructure that works with more than 1 host?

A load balancer in front of a server farm may make a lot more sense.

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There’s no limit hard coded into Asterisk, limits will fall on your hardware and bandwidth


If you are able to stabilize the system then thats all you need to push the limit. I have seen close to 5k (g729 codec) simultaneous calls without any issues. Of course it depends on hardware and bandwidth as @jsmith and @lostpacket pointed out correctly. Thank you.

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