An AAA based Architecture for Providing Differentiated Services to Mobile IP Users

Current Differentiated Services (DiffServ) are not yet fully adapted and integrated with mobile environments, especially when Mobile IP \cite{Mobile} is used as the mobility management protocol in the Internet. When a mobile node (MN) visits a foreign network and requests services based on Service Level Agreements (SLAs), the DiffServ Internet Services Providers (ISPs) must care about how to charge the mobile user. In addition, SLAs have to be renegotiated between home / foreign links and their ISPs. Additional authentication, authorization and accounting (AAA) procedures must be provided for this case. This paper proposes a concept to combine the Service Location Protocol (SLP) and the Mobile IP AAA based architecture and presents a new extended AAA architecture which is independent of the availability of a foreign agent (FA) and works for IPv4 or IPv6 in a uniform manner. In this model, the MN becomes truly able to roam throughout the Internet, while needing substantially less administrative overhead. It only needs a password and a NAI to formulate its global passport. We provide a new feasible method of transferring the MN's SLA stored in the home domain to the foreign domain in a more secure and scalable manner. Meanwhile, several new IP options are also proposed in order to allow the MN to flexibly renegotiate the service level. In particular, the architecture supports mobile telephony over packet-based IP networks without having the need for GSM-like mobility management and accounting schemes. To conclude, a detailed specification about Quality-of-Service (QoS) signaling protocol for Mobile IP nodes is included. Once available, the AAA protocol and infrastructure will provide the economic incentive for a wide-ranging deployment of DiffServ in mobile environments.