Roland, At 2017-02-22 20:57:34 +0000 Roland Perry <roland@internetpolicyagency.com> wrote:
In message <4C47D72B-8A25-4CFE-AF61-B7347F726579@ripe.net>, at 12:32:33 on Thu, 16 Feb 2017, Chris Buckridge <chrisb@ripe.net> writes
LEA interest in reducing the use of CGN also came up for discussion at the recent RIPE NCC Roundtable Meeting for Governments and Regulators (held in Brussels on 24 January)
The UK's approach, as expressed in the 2016 IP[1] Act, is not to prohibit CGN, but require operators to log who was using which IP, when.
IP+port, right?
This is exactly the same as when Internet access was primarily by dial-up to banks of modems, and customers shared the IP Address of the modem. The ISPs were expected to log who had been online at a specific IP address at a specific time.
It's not exactly the same, because a dial-up session was expected to be several minutes or even hours. A single IP+port may be used for less than a second. Plus there is likely an extra layer of indirection. A NAT device may know the customer private IP address and the public IP address, but might not necessarily have access to the database which assigned the customer to the private IP address. So that data also needs to be logged & correlated. If LEA are expected to pay for all of this extra storage and processing - or even if it just makes investigations slower - then I can easily understand why they would want to reduce the use of CGN. (If that cost gets eaten by ISP, then the push will naturally go towards fewer CGN without any encouragement by the LEA.) Cheers, -- Shane