How Many IPs Does a New York Carrier Line Rotate Through?

Customers want a number. How many different addresses will my line give me in a day, a week, a month? We can give you the shape of the answer and some observations from our own racks, but not a fixed figure, because the carrier decides and the carrier does not publish it. What follows is what we actually know from running Verizon, AT&T and T-Mobile lines in Brooklyn, Queens and Manhattan.

Where the addresses come from

When a modem registers on the network, the carrier's packet core assigns it a private address and maps it to a public one at a gateway. That gateway serves a region, not a tower, and it owns a set of public blocks. Every public address your line will ever see comes from that regional set. For the New York metro the sets are large on all three carriers, because the carriers have to serve millions of subscribers in the area at once.

You will see these addresses attributed to the carrier's network: AT&T Mobility on AS20057, T-Mobile USA on AS21928, and Verizon Wireless as Cellco on AS6167 and AS22394. Geolocation reads them as New York. Not Brooklyn, not Queens, not a ZIP code that means anything; the city, because the gateway is where the traffic leaves.

What a rotation actually does

A rotation on our side tears down the modem's data session and brings it back up. The carrier then assigns an address from the pool again. Often it is a different one. Sometimes, especially on a quiet line at a quiet hour, it is the one you just had, because the gateway reused the slot. There is no waiting time between rotations on our side, so if you get a repeat you can simply rotate again.

Rotation is triggered from the dashboard button, from a rotation link you can call from anything, from the API, from a timer you set on the line, or by hand if you like doing things by hand. All of them do the same thing underneath.

Repeats, and why you should expect them

People sometimes count distinct addresses over a day of rotating every few minutes and are surprised to see some come back. That is the pool working as designed. The gateway hands out addresses from a finite set, and many thousands of phones are drawing from the same set, so the one you release goes back in the pile and might come out again later. On a busy weekday in New York we see fewer repeats in a given hour than at four in the morning, which fits what you would expect from how many phones are active.

A repeat does not hurt you. A real phone in the city sees repeats too. Sites that track addresses see a carrier address that was used by many people earlier and is used by many people now.

Rough observations from our racks

We are deliberately not giving you a count, because any count would be true for one line on one day and false the next. What we can say is this. On Verizon in Brooklyn, rotating every ten minutes through a working day, a line typically moves through a wide spread of addresses across several of Verizon's New York blocks before repeats become common. On AT&T in Queens the spread is similar, with sessions that tend to change on their own more often even without a rotation request. T-Mobile sits between the two. Across a month, a line that rotates regularly will have touched a large share of the pool it can reach, and will have repeated plenty of them.

• The pool is regional and shared, so distinct-address counts depend on the hour and the day
• Repeats are normal and increase the more often you rotate
• Rotating more than once every few minutes mostly gives you repeats faster, not more addresses

Sticky time: the other half of the question

The flip side of how many is how long. If you never rotate, the address stays until the carrier reassigns it. On Verizon lines in Brooklyn that is often most of a day and sometimes longer. AT&T lines in Queens change on their own more frequently; a few hours is common. T-Mobile is in the middle. None of this is a promise, it is what the monitoring shows most days. If your job needs a fixed address for a long stretch, Verizon is the better bet, and you should avoid anything that triggers a rotation, including timers you forgot you set.

Choosing a rotation strategy for a New York job

For account work, do not rotate during a session. Rotate between sessions at most, and only if the job needs it. For reading many pages on one site, rotate on a timer that matches how a person would behave, not every request; a real visitor's address does not change on each click. For checking how a listing, a price or an ad shows to different New York carrier users, rotate between checks and consider a line on each carrier, since the carrier is a bigger difference than the address within a carrier.

And if you want more distinct addresses per hour than one line can give, the honest answer is a second line, not a faster rotation timer. Lines are $5 a day on 4G or $65 a month, and two lines on two carriers double your spread in a way one line never can.

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