AS20057 166.171.48.0/21 CIDR and IP Range Summary.ASN: 20057 - AT&T Mobility LLCHost Count: 2046Addressable IPs: 2048166.171.48.0/24166.171.49.0/24166.171.50.0/24166.171.51.0/24166.171.52.0/24166.171.53.0/24166.171.54.0/24166.171.55.0/24