AS20057 107.90.136.0/21 CIDR and IP Range Summary.ASN: 20057 - AT&T Mobility LLCHost Count: 2046Addressable IPs: 2048107.90.136.0/24107.90.137.0/24107.90.138.0/24107.90.139.0/24107.90.140.0/24107.90.141.0/24107.90.142.0/24107.90.143.0/24