How Many IPs Does a US Mobile Proxy Rotate Through?

A single US mobile proxy rotates through the public IPv4 addresses that its carrier's regional gateway hands out, which in a large metro is typically a pool of several thousand addresses, of which one line will see tens to a few hundred distinct addresses in a day depending on how often it rotates. The exact number is set by the carrier, varies by city and gateway, and cannot be chosen by the proxy provider. This page explains where the pool comes from, how a rotation picks from it, why the same address comes back, and how to measure the pool a given Mobile Proxy USA line actually sees.

Where the pool comes from

Each carrier runs translation gateways that serve a region. A phone, or a proxy modem, holds a private address inside the carrier network and is mapped to one of the gateway's public addresses when its traffic leaves. The set of public addresses at a gateway is the pool. The carrier sizes it for the subscribers in that region, not for proxy users, and it is shared by all of them. A gateway serving a metro of several million people has a pool in the thousands of addresses; a smaller region has fewer.

The pool is therefore a property of the carrier, the region and the moment. AT&T, T-Mobile and Verizon each have their own, and the same carrier has a different pool in Chicago than in Miami. No provider can promise a particular pool size, and a provider that quotes one exact figure is describing a measurement, not a guarantee.

What a rotation does

A rotation on a Mobile Proxy USA line disconnects the modem's data session and reconnects it. The carrier assigns the new session a public mapping from whatever is free at the gateway. The new address is usually different from the previous one, but it is drawn from the same pool, so it can be one the line held earlier in the day. Rotation can be triggered by a link, by the API, from the dashboard, on a timer, or by hand, with no limit on how often. Each rotation takes a few seconds, during which the line is briefly unreachable.

Some Verizon gateways tend to return the same public address to a device that reconnects quickly. On such a line, a rotation that produces the same address is normal; a second rotation a short time later usually produces a new one.

How many distinct addresses one line sees

Rotating every few minutes for a full day on a line in a large metro commonly yields between a few dozen and a few hundred distinct addresses, with repeats increasing as the day goes on. Over a month the count grows but flattens, because the pool is finite and the line keeps meeting addresses it has already held. A line that is left alone sees far fewer: the carrier changes the address on its own only occasionally, so a sticky line may hold one address for many hours or days.

The count is not the same as the number of identities the line can present. Because the pool is shared with real subscribers, each address is also in use by many phones at once, and a website does not treat two visits from the same carrier address as the same person. Many jobs that seem to need a large pool actually need only a clean carrier address, which every rotation provides.

Measuring the pool on your own line

The measurement is simple. Call the rotation link, wait for the modem to reconnect, request an IP lookup through the line and record the address, then repeat on a fixed interval for a day. The number of distinct addresses divided by the number of rotations shows how quickly repeats appear. A script of a dozen lines does this; the Mobile Proxy USA API returns the current address so no external lookup is required. Running the same measurement on a line in a different city or carrier, which is free to move to, shows which pool suits the job.

When pool size matters and when it does not

Pool size matters for jobs that must spread many requests across many addresses in a short time, such as large-scale collection of public pages from a site that limits requests per address. Even then a carrier address tolerates far more requests than a datacenter address before a site reacts, because the site expects many users behind it. Pool size does not matter for account work, where one stable address per account is the goal, for ad verification, for localisation checks, or for any job that is about seeing what a user in a city sees. For those, a dedicated line with unlimited data and rotation on demand is the whole requirement, and the pool is simply where the next address comes from.

Mobile Proxy USA sells each line with unlimited rotation included. Buyers who need breadth run several lines in several cities, each drawing on a different pool, rather than paying by the gigabyte for a shared one.

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