Related Work EDNS0 is recommended here: In practice, you will have problems if it is not supported Particularly over “long pipes” such as cellular access networks, using TCP fallback is painful, and will result in unacceptably long delays (seconds) Given that some territories regulate the maximum time before a call is placed, this may be a problem unless EDNS0 is available Parallel Effort to produce a document just for EDNS0 Status is still under discussion with DNSOPS Reviewer (Lars-Johan Liman) to decide on capitalisation of MUSTs New version will be issued once this is completed |