In some scenarios, an IP-based device is required to authenticate itself to the network prior to being authorized to use it. This authentication usually requires a protocol that can support various authentication methods, dynamic service provider selection, and roaming clients. In the absence of such an authentication protocol on most of the link-layers, architectures have resorted to filling the gap by using a number of inadequate methods. For example, inserting an additional layer between link-layer and network-layer mostly for client authentication purpose (e.g., PPPoE), overloading another network-layer protocol to achieve this goal (e.g., Mobile IPv4 with Registration- required flag), and even defining application-layer ad-hoc authentication mechanisms (e.g., http redirects with web-based login). In these and other cases, a network-layer authentication protocol may provide a cleaner solution to the authentication problem.
The goal of PANA is to define a protocol that allows clients to authenticate themselves to the access network using IP protocols. Such a protocol would allow a client to interact with a site's back-end AAA infrastructure to gain access without needing to understand the particular AAA infrastructure protocols that are in use at the site. It would also allow such interactions to take place without a link-layer specific mechanism. PANA would be applicable to both multi-access and point-to-point links. It would provide support for various authentication methods, dynamic service provider selection, and roaming clients.
Mobile IPv4 developed its own protocols for performing PANA-like functions (e.g., MN-FA interaction). Mobile IPv6 does not have the equivalent of a Foreign Agent (FA) that would allow the access/visited network to authenticate the MN before allowing access. The PANA authentication agent (PAA) can perform the authentication function attributed to the FA in Mobile IPv4, in Mobile IPv6 networks.
The WG will work with the assumption that a PANA client (PaC) is already configured with an IP address before using PANA. This IP address will provide limited reachability to the PaC until it is authenticated with the PAA. Upon successful authentication, PaC is granted broader network access possibly by either a new IP address assignment, or by enforcement points changing filtering rules for the same IP address.
PANA will neither define any new authentication protocol nor define key distribution, key agreement or key derivation protocols. It is believed that PANA will be able to meet its goals if it is able to carry EAP payloads. Note, however, that EAP may need to be extended in order for PANA to meet the need for all of its intended usages. Such extensions are outside the scope of the PANA WG.
PANA will develop an IP-based protocol that allows a device to authenticate itself with the network (and to a PAA in particular) in order to be granted network access. The PAA itself may interface with other AAA backend infrastructures for authenticating and authorizing the service being requested by the host, but such interactions are transparent to the PaC.
Network access authentication enables the client to be authorized for packet data service. However it is possible that the underlying link itself is insecure, i.e the packets being transmitted between the client (PaC) and the enforcement point (EP) in the network are not protected by any physical or cryptographic means. In such cases, PANA will enable the establishment of an IPsec SA between the PaC and the EP (a router) to enable access control. In networks that have physical security or ciphering as a link-layer feature, no such SA is required. Hence the establishment of the IPsec SA is optional. The WG will deliver a document that explains how such an IPsec SA is established by using IKE after successful PANA authentication. No enhancements to either IKE or IPsec are expected.
The PAA does not necessarily act as an enforcement point (EP) to prevent unauthorized access or usage of the network. When a PaC succesfully authenticates itself to the PAA, EP(s) (e.g., access routers) will need to be suitably notified. SNMP will be used by the PAA to deliver the authorization information to one or more EPs when the PAA is separated from EPs. The WG will document the solution based on SNMP for carrying the authorization information between the PAA and the EP.
The WG will also propose a solution of how the PaC discovers the IP address of PAA for sending the authentication request.
The PANA WG will deliver
- A mechanism for the PAC to discover the PAA on the link.
- The PANA protocol itself, capable of carrying multiple authentication methods (e.g. using EAP)
- A document that describes how SNMP is used to deliver authorization information from the PAA to the EP in the scenarios where the PAA and EP are separated.
- A document that explains the establishment of an IPsec SA between the client and a router (EP) subsequent to authentication for securing the data packets.
Submit MIB for PANA to the IESG
Submit PANA mobility optimizations to the IESG
Submit PANA-AAA interactions document to the IESG
Submit SNMP-based PAA-to-EP protocol specification to the IESG
Submit PANA state machine specification to the IESG
Submit PANA protocol specification to the IESG
Submit PANA framework to the IESG
Submit IPsec-based access control to the IESG
Submit protocol requirements to the IESG
Submit security threat analysis to the IESG
Submit usage scenarios and applicability statement to the IESG