The Domain Policy DDDS Application draft-lendl-domain-policy-ddds-00 draft-lendl-speermint-federations-00 Otmar Lendl Otmar.Lendl@enum.at 2006/03/15 Domain Policy DDDS

Introduction Interconnect SIP-based networks (enterprise and service providers) directly via SIP Avoid transcoding, enable wideband codecs Avoid service limitations (presence, IM, Video, …) Cost saving Avoid drawbacks of the open Internet model Spam/Spit Lack of trusted CallerID Selective and controlled association 2006/03/15 Domain Policy DDDS

Evolution (1) VoIP Service Providers interconnect via PSTN using E.164 numbers for addressing VSP VSP VSP VSP VSP PSTN Plane +4315056416 2006/03/15 Domain Policy DDDS

Evolution (2) User ENUM can be used to route calls over the public Internet. Public Internet User ENUM sip:office@enum.at VSP VSP VSP VSP VSP PSTN Plane 2006/03/15 Domain Policy DDDS

Evolution (3) The reality is more complex: Public Internet PSTN Plane Private Interconnection Network Private Interconnection Network sip:office@enum.at VSP VSP VSP VSP VSP Public Internet Closed SIP federation PSTN Plane 2006/03/15 Domain Policy DDDS

Problem Statement Destination VSP Calling VSP can be member of several VoIP peering fabrics. may also accept calls over the Internet from certain parties. Calling VSP needs to find a path to the destination VSP. can also be member of some (potentially different) VoIP peering fabrics. Trial and Error during call-setup is not a good idea. Thus he needs to discover which peering fabrics they share. How does the calling VSP do this? 2006/03/15 Domain Policy DDDS

Proposed Solution Destination VSP publishes his reachability List of his federation memberships Other ways of reaching him Calling VSPs Fetches this policy set Compares this to his own membership list Protocol DDDS Application to map domains to policy sets. 2006/03/15 Domain Policy DDDS

Big picture Dialstring normalization E.164 based dialing starts here Dialstring normalization Destination URI Discovery (I-ENUM) Destination URI Policy Discovery Path (fabric) selection Call setup over discovered path Call admission … URI based dialing starts here 2006/03/15 Domain Policy DDDS

Federations A Federation is a group of VoIP service providers / enterprises which agree to receive calls from each other via SIP agree on a set of administrative rules for such calls (settlement, abuse-handling, ...), and agree on specific rules for the technical details of the interconnection. Federations have a unique identifier 2006/03/15 Domain Policy DDDS

Federation examples TLS based Private Network Public Internet, SIP over TLS, Federation acts as X.509 Certification Authority. Private Network Federation builds its own network (the GRX case), members connect directly over this network. SIP Hubs / Transit networks Calls are routed via a central SIP proxy 2006/03/15 Domain Policy DDDS

Domain Policy DDDS basics The domain is the key to the destination policy Use the DNS as rule store No special translation rules necessary Infrastructure is in place Example: example.com. IN NAPTR 10 50 "U" "D2P+SIP:fed" "!^.*$!http://sipxconnect.example.org/!" . “Regarding SIP, example.com is a member of the federation identified by this URI.” Non-terminal NAPTR for customer domains referring to provider domains Protocol agnostic SIP is just a special case 2006/03/15 Domain Policy DDDS

Policy Rule Elements A NAPTR record contains a single policy rule Examples A federation membership draft-lendl-speermint-federations-00 A technical restriction e.g. a specific anti-SPIT rule examples in draft-lendl-sip-peering-policy-00 A reference to an external policy document e.g. SAML or XACML 2006/03/15 Domain Policy DDDS

Complex Rule Sets A NAPTR RRSet defines the policy of a domain. “order” and “preference” define a Boolean expression of individual policy rules. Example: $ORIGIN example.com. ; order pref flags service regexp replacement (1) IN NAPTR 10 50 "U" "D2P+SIP:fed" "!^.*$!http://sipxconnect.example.org/!" . (2) IN NAPTR 20 10 "U" "D2P+SIP:std" "!^.*$!urn:ietf:rfc:2246!" . (3) IN NAPTR 20 15 "U" "D2P+SIP:std" "!^.*$!urn:ietf:rfc:3711!" . (1) OR ( (2) AND (3) ) RFC2246: TLS RFC3711: srtp 2006/03/15 Domain Policy DDDS

Summary draft-lendl-domain-policy-ddds-00 solves: Out of scope: Policy announcement (“I am member of federations X and Y”) Policy discovery (“I’ll reach the destination through federation Y”) Enables ad-hoc peering under clearly defined rules One step towards satisfying the requirements of draft-ietf- speermint-reqs-and-terminology-01 Out of scope: Peering rules within federations It’s not about how to peer, but how to select which peering method/fabric to use. 2006/03/15 Domain Policy DDDS