Comment Re:Wish they would use ANI instead of CID (Score 5, Informative) 206
Still, although ANI may not be "spoofable," it can be manipulated or uninformative. For example, any call placed from any phone in my office carries a general company ANI even though the call could be originated from any of hundreds of phone numbers owned by the firm. We also have off-premise extensions (OPXs) that connect to the office PBX via SIP. Calls placed from those OPXs have the same ANI as calls made from the physical office, which would be deleterious if a call was placed to 911 from one of these phone. (We have implemented a safety workaround for this, but the point still stands.)