Anecdotally I don't know of a single ISP that buys N x 10 Gbps transpacific or transatlantic waves/transport (ex: one Wilshire to Equinix Tokyo) that uses link layer crypto. In my example the ISPs are customers of the organizations that actually run the DWDM terminals.
Highly redundant core routers like an asr9010 with 2nd/3rd gen line cards, or an mx960 are already expensive enough without making a 24-port 10GbE linecard twice as costly to buy by having crypto features. It is super rare to see such hardware in production for commercial ISPs.
Highly redundant core routers like an asr9010 with 2nd/3rd gen line cards, or an mx960 are already expensive enough without making a 24-port 10GbE linecard twice as costly to buy by having crypto features. It is super rare to see such hardware in production for commercial ISPs.