AT&T proxies — AS20057 mobile and AS7018 fixed exits

AT&T is two ASNs, one strategy

AT&T operates a dual-ASN architecture that differs meaningfully from T-Mobile or Verizon. AS20057 is AT&T Mobility — the wireless-only ASN covering 4G LTE, 5G, and FirstNet allocations. AS7018 is AT&T Internet — the fiber and DSL residential backbone, plus business internet and Mid-Atlantic / Southern fiber transit. Historically these were separate companies (AT&T Mobility = Cingular + Bellsouth Mobility; AT&T Internet = SBC + legacy AT&T Corp + bits of Bellsouth Wireline). They share a brand and a parent, but they route separately on the public internet.

For Proxaro purposes this matters because an AT&T Mobility 4G exit (AS20057) and an AT&T Fiber residential exit (AS7018) both resolve to "AT&T" on commercial GeoIP — but fingerprint quite differently in trust-graph lookups. We separate them in the API: pass X-PX-Asn: as20057 for mobile, X-PX-Asn: as7018 for fixed.

Subscriber and footprint scale

As of AT&T's Q4 2024 10-K filing, AT&T Mobility carries approximately 120M US wireless subscribers — third-largest after T-Mobile and Verizon but with a significant gap. AT&T Internet has approximately 14M fiber + U-verse residential subscriptions, concentrated in Texas, California, and the Southeast.

AT&T's geographic core is the South — it's the direct corporate descendant of Southern Bell and SBC, and its density bias shows:

• Texas: AT&T's HQ state (Dallas-based) and the single densest AT&T Mobility + AT&T Fiber footprint in the country.
• Georgia: Atlanta is AT&T's second-largest operational metro; significant legacy BellSouth territory.
• Florida: Strong residential fiber and mobile density across the state.
• California: Legacy Pacific Bell / SBC territory; very dense in LA and the Central Valley.
• Tennessee: Nashville and Memphis are both AT&T-leading markets.

AT&T's 5G story

AT&T's standalone 5G rollout has been the slowest of the big three in 2025-26. Most AT&T "5G" in consumer-facing marketing is 5G NSA (non- standalone — it's 5G radio anchored to an LTE core). Standalone 5G is available only in select markets and not yet at the scale of T-Mobile SA. For most AT&T rotation on Proxaro in 2026, you're on NSA or on LTE Advanced, not on an SA core.

When AT&T is the right pick

• Texas-region work where the carrier's home-state density gives cleaner ZIP-level IP resolution and higher trust weight.
• Southeast metros (Atlanta, Nashville, Charlotte, Raleigh, Jacksonville) where AT&T is the dominant commercial carrier.
• Workflows against FirstNet-adjacent public-safety sites where AT&T's FirstNet allocation delivers the correct ASN.
• Brand-safety or creative-QA work where a target has historically weighted "AT&T legacy carrier" trust more than newer entrants.

FirstNet

AT&T runs the FirstNet network — a public-safety broadband allocation carried on a separate spectrum band (Band 14) and announced from a subset of AS20057 prefixes. FirstNet IPs resolve to "AT&T FirstNet" on detailed commercial GeoIP databases and are treated as distinct. Proxaro's standard AT&T Mobility pool excludes FirstNet prefixes — we don't route traffic through public-safety allocations, and we'd advise against it for compliance reasons.

MVNOs on AT&T

Cricket Wireless is AT&T's flagship prepaid MVNO and announces under AS21928 through the AT&T core. Consumer Cellular, H2O Wireless, and several regional resellers also sit on AT&T. MVNO fingerprinting is carrier-specific — some platforms weight Cricket as a lower-trust variant of AT&T. Proxaro's AT&T pool is host-only by default.

Pricing and pool access

AT&T ASN pinning is available on Carrier and above. Recommended starting state pools: Texas, Georgia, Florida, California, Tennessee.

References

• AT&T 2024 10-K: wireless subscriber counts and fiber footprint
• peeringdb.com — AS20057 AT&T Mobility, AS7018 AT&T Internet
• bgp.tools AS7018 — prefix announcement inventory, peering data
• Statista: US mobile carrier market share 2024-25