A number of IETF documents(*) state that there are some service providers that place a NAT box in front of their entire network, so all their customers get private addresses rather than public address. It is often stated that these are primarily cable-based providers. I am trying to get a handle on how common this practice is. No one that I have asked seems to know any provider that does this, and a search of a few FAQs plus about an hour of Googling hasn't turned up anything definite (but maybe I am using the wrong keywords ...). Can anyone give me some names of providers that do this? Can anyone point me at any documents that indicate how common this practice is? - Philip (*) Some IETF documents that mention this practice: - RFC 3489 - draft-ietf-sipping-nat-scenarios-00.txt (now expired, but available at http://www.ietf.org/proceedings/02jul/I-D/draft-ietf-sipping-nat-scenarios-0...