Oration Supplier

Telephony Channel Calculator

Estimate how many channels and CPS you need to run your AI voice agent campaigns.

Campaign parameters

Total calls = leads × (1 + re-attempts)

e.g. 480 min = 8 hrs

Your desired floor for parallel calls

For answered calls only

Channel held until unanswered call drops

Standard is 20 channels : 1 CPS

Safety margin added to final channel count

Count ringing channels
ON = channel is held while the phone rings (most providers). OFF = channel is only occupied once the call is answered.

Results

Channels required

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CPS required

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Total calls

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Bottleneck & channel breakdown

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Inbound parameters

e.g. 600 min = 10 hrs

Max parallel calls at any instant

Sets the minimum channel floor

Results

Channels required

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CPS (provisioned)

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Derived from channel count

Inbound CPS (traffic)

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Bottleneck & channel breakdown

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Two concepts you need to understand first

Every number this calculator produces comes from two telephony concepts. It is important to understand the difference between them before reading the formulas.

Channels — parallel calls

A channel is one live telephone connection. If you have 50 channels, you can have 50 calls happening at the same time. Think of it like lanes on a highway — more lanes, more simultaneous traffic.

CPS — dialing speed

CPS (Calls Per Second) is how fast you can start new calls. Even if you have enough channels, a low CPS limit will slow down how quickly your campaign can dial. Think of it like the rate of cars entering the highway per second.

The key rule: Most telephony providers enforce a ratio of 20 channels per 1 CPS. This means if your traffic needs 2 CPS of dialing speed, the provider will require you to have at least 40 channels provisioned — even if your call volume alone would only need 30. The two numbers are always linked.

Outbound — how the channel count is calculated

For outbound campaigns, the calculator works out three independent requirements and then takes the largest one as the final answer. Here is each step explained.

Step 1 — total calls & required CPS

Total calls = Leads × (1 + Re-attempts)
Required CPS = Total calls ÷ (Calling window in seconds)
Calling window in seconds = Calling window in minutes × 60

First we count all the calls your campaign needs to make. If you have 5,000 leads and want to try each one 2 more times if they do not pick up, that is 5,000 × 3 = 15,000 total calls.

Then we divide by the window length in seconds to find your Required CPS — the minimum dialing speed your campaign needs to complete all those calls in time. For example, 15,000 calls in 8 hours (28,800 seconds) needs 0.52 CPS.

Step 2 — channels from call traffic

At any given moment, your channels are occupied by two kinds of calls — ones that got picked up and are actively being handled, and ones that are still ringing but have not been answered yet. Both types hold a channel open.

Answered CPS = Required CPS × Pickup rate
Unanswered CPS = Required CPS × (1 − Pickup rate)
Channels (answered calls) = Answered CPS × Avg call duration (seconds)
Channels (ringing calls) = Unanswered CPS × Ring time (seconds)
Channels from Traffic = Channels (answered) + Channels (ringing)

This uses a principle from queuing theory called Little's Law: the average number of things in a system equals the rate they arrive multiplied by the average time each one spends there.

Example: if 0.13 calls per second get answered and each call lasts 240 seconds, you need 0.13 × 240 ≈ 31 channels just for active conversations. Plus, if 0.39 calls per second ring without being answered and each rings for 30 seconds, that is another 0.39 × 30 ≈ 12 channels just for ringing. Total traffic requirement: roughly 43 channels.

Step 3 — channels from the CPS ratio

Channels from CPS = ⌈Required CPS⌉ × 20
⌈ ⌉ means round up to the nearest whole CPS unit

Your telephony provider enforces a hard link between CPS and channels. If your campaign needs 0.52 CPS, the provider rounds that up to 1 CPS and requires you to have at least 20 channels provisioned for it — regardless of what the traffic calculation says.

This constraint often surprises customers. A campaign with very short calls and high volume can demand surprisingly little concurrent channel load from a traffic perspective, but still need a large channel count just to support the dialing speed.

Step 4 — minimum concurrency floor

Channels from Concurrency = Your minimum setting (entered directly)

Sometimes a customer knows they want a minimum number of parallel calls running regardless of what the math says — for example, to maintain a consistent campaign pace. This number is taken directly from your input and compared against the other two constraints.

Step 5 — final answer & bottleneck

Raw channels = Maximum of (Traffic, CPS ratio, Concurrency)
Final channels = ⌈Raw channels × (1 + Buffer %)⌉
Final CPS = ⌈Final channels ÷ 20⌉

We take the largest of the three requirements — that is the bottleneck, the constraint actually limiting your campaign. A buffer (default 20%) is added on top to handle unexpected spikes. The final CPS is then derived back from the final channel count.

What each bottleneck means

Bottleneck What it means What to do
Call traffic volume Your combination of call volume, pickup rate, and duration is the main driver. Your calls stay on the line long enough to stack up. Reduce call duration, narrow the calling window, or lower re-attempts to free up channels.
CPS-to-channel ratio Your required dialing speed is forcing a higher channel count than the traffic alone would need. Your calls are probably short or your pickup rate is low. Spread the same volume over a longer calling window to lower your required CPS.
Minimum concurrency Your manually set floor is higher than what traffic or CPS requires. You are buying extra capacity intentionally. No action needed — this is a deliberate choice. Reduce it if you want to optimise costs.

Inbound — how the channel count is calculated

Inbound is simpler. You are not driving the calls — your customers are. So instead of estimating dialing load, we look at two constraints that define the minimum number of channels you must always have open.

The two constraints

Channels from Peak = Peak concurrent calls (entered directly)
Channels from Agents = Number of human agents (the minimum floor)
Raw channels = Maximum of (Peak concurrent, Human agents)
Final channels = ⌈Raw channels × (1 + Buffer %)⌉
Final CPS = ⌈Final channels ÷ 20⌉

Peak concurrent calls is the maximum number of calls you expect to be live at the same moment. If that number is 50, you need at least 50 channels — otherwise some callers will get a busy signal.

Human agents floor exists because of how AI-to-human transfer works. When the AI decides to hand off a call to a human agent, a channel must be available for that transfer. If you have 20 agents sitting and waiting, you need at least 20 channels reserved to cover those potential transfers — even during quiet periods. The channel count can never be lower than your agent headcount.

Why daily volume and calling window are shown: These inputs let you see the average incoming CPS across your operating hours. This is not a constraint — it is informational, helping you check whether your peak concurrency estimate is realistic given how many calls you expect per day.

What each bottleneck means (inbound)

Bottleneck What it means What to do
Peak concurrent calls Your busiest moment — how many callers are on hold or talking simultaneously — is driving the channel requirement. Consider load balancing, call deflection strategies, or accepting that channels must match your peak demand.
Human agent floor You have more agents than your peak concurrent call estimate. Every agent represents a potential transfer that needs a live channel. Either increase your peak concurrent estimate (it may be underestimated) or review whether all agents need to be simultaneously reachable.

Advanced assumptions — what the defaults mean

These values can be changed in the Advanced section of each calculator tab. Here is what each one does and why the default was chosen.

Ring time (default: 30 seconds)
How long a call rings before being treated as unanswered and dropped. A channel is occupied for this entire duration even if nobody picks up. At high dial rates, ringing calls can consume a surprising number of channels. Only relevant when "Count ringing channels" is ON.
Count ringing channels (default: ON)
Controls whether unanswered calls consume a channel while the phone is ringing. ON — The channel is reserved from the moment the call is dialled until the caller hangs up or the ring time elapses. This is the conservative, safe assumption and reflects how most telephony providers work. OFF — The channel is only counted once the call is answered. Some providers handle the ring phase on their own infrastructure and only assign you a channel slot at the point of pickup. Switch this OFF only if your provider has explicitly confirmed this behaviour. Toggling this OFF will lower your traffic-based channel estimate, sometimes significantly — especially at low pickup rates with long ring times.
CPS to channels ratio (default: 20)
The standard ratio enforced by most telephony carriers. If your provider uses a different ratio, override this value here. Changing it affects how many channels the CPS constraint demands.
Headroom buffer (default: 20%)
A safety margin added on top of the calculated channel count. Real-world traffic has spikes — this buffer prevents dropped calls during surges. 10% is reasonable for predictable outbound lists; 30%+ for volatile inbound traffic.