The IP Multicast service model extends the traditional best effort Internet datagram delivery service for efficient multi-point packet delivery. However, in spite of a decade of research on multicast protocols and applications, a globally deployed multicast service is nowhere in sight, hindered by multitudes of problems such as manageability, lack of a robust inter-domain multicast routing protocol, scalability, and heterogeneity. In this work, we propose a new model for Internet multicast where we view multi-point delivery not as a network primitive but rather as an application-level infrastructure service. Our architecture relies on a collection of strategically placed network agents that collaboratively provides the multicast service for a session. Clients locate a nearby agent and tap into the session via that agent. Agents organize themselves into an overlay network of unicast connections and build data distribution trees on top of this overlay structure. This model effectively pa...

The cost savings and novel features associated with Voice over IP (VoIP) are driving its adoption by service providers. Such a transition however can successfully happen only if the quality and reliability offered is comparable to the existing PSTN. Unfortunately, the Internet’s best effort service model provides no inherent quality of service guarantees. Because low latency and jitter is the key requirement for supporting high quality interactive conversations, VoIP applications use UDP to transfer data, thereby subjecting themselves to performance degradations caused by packet loss and network failures. In this paper we describe two algorithms to improve the performance of such VoIP applications. These mechanisms are used for localized packet loss recovery and rapid rerouting in the event of network failures. The algorithms are deployed on the routers of an application-level overlay network and require no changes to the underlying infrastructure. Initial experimental results indicate that these two approaches can be composed to yield voice quality on par with the PSTN.

The combined force behind ubiquitous mobile computing and storage devices and universal network access has created a unique era of mobile network computing, in which computation units ranging from a single process to an entire host can move while communicating with each other across the network. A key problem therefore is how to preserve the ongoing network communication between two computation units when they move from one place to another; because current network infrastructure and protocols are designed to support stationary commu-nication endpoints only. We have developed MOVE, a fine-grain end-to-end connection migration architec-ture, to address the problem. The most distinguishing characteristic of MOVE is that MOVE achieves, in a single system, several essential goals of a mobile commu-nication architecture including: (1) entirely end system only without any infra-structure demand, transport protocol independence, and backward compatibility; (2) fine-grain connection migration and unlimited mobility scope; (3) secure migration with both handoff and suspension/resumption support; and (4) very

Abstract — The cost savings and novel features associated with Voice over IP (VoIP) are driving its adoption by service providers. Unfortunately, the Internet’s best effort service model provides no quality of service guarantees. Because low latency and jitter is the key requirement for supporting high quality interactive conversations, VoIP applications use UDP to transfer data, thereby subjecting themselves to quality degradations caused by packet loss and network failures. In this paper we describe an architecture to improve the performance of such VoIP applications. Two protocols are used for localized packet loss recovery and rapid rerouting in the event of network failures. The protocols are deployed on the nodes of an application-level overlay network and require no changes to the underlying infrastructure. Experimental results indicate that the architecture and protocols can be combined to yield voice quality on par with the PSTN. I.

This paper addresses the issue of defining a location service suitable for very dynamic and highly populated networks (millions of users), where services might experience highly correlated peaks of traffic or synchronized access to specific servers. A cooperative mobile agent solution is proposed to solve the major problems, allowing the dynamic deployment of new application servers when needed. But it requires an adequate location service to route the clients to the application servers, which scales to a large number of clients and still allows a high number of updates. This paper presents a very dynamic location service, which adapts to overload situations by modifying the routing information distribution and (possibly) its servers ’ internal structure. The responsive and fast route update results in a load redistribution, which allows it to scale to a broader range compared to other alternative approaches. I.

This paper presents three new mechanisms for the Service Location Protocol (SLP): mesh enhancement, preference filters and global attributes. The mesh enhancement simplifies Service Agent (SA) registrations and improves consistency among Directory Agents (DAs) by defining an interaction scheme for DAs and supporting automatic registration distribution among peer DAs. Preference filters facilitate processing of search results (e.g., finding the best match) in SLP servers (DAs and SAs) to reduce the amount of data transferred to the client for saving network bandwidth. Global attributes allow using a single query to search services across multiple types. These mechanisms can improve SLP efficiency and scalability and support advanced discovery such as discovering multi-access-point services and multi-function devices. We expect that these techniques can also be applied to other service discovery systems.

We present the Internet Key Service (IKS), a distributed architecture for authenticated distribution of public keys, layered on Secure DNS (DNSSEC). Clients use DNSSEC to securely discover the identities of the relevant IKS servers, and send key lookup or management requests directly to these servers using a special-purpose protocol. Clients authenticate keys retrieved from IKS servers using key commitments published in DNSSEC. IKS derives its authentication authority from the authority DNS domains have over Internet names. The IKS architecture is loosely coupled with DNS to minimize overhead on DNS servers. We also present RIKS, a prototype IKS implementation. 1.

Abstract—The Host Identity Protocol (HIP) is an internetworking architecture and an associated set of protocols, developed at the IETF since 1999 and reaching their first stable version in 2007. HIP enhances the original Internet architecture by adding a name space used between the IP layer and the transport protocols. This new name space consists of cryptographic identifiers, thereby implementing the so-called identifier / locator split. In the new architecture, the new identifiers are used in naming application level end-points (sockets), replacing the prior identification role of IP addresses in applications, sockets, TCP connections, and UDP-based send and receive system calls. IPv4 and IPv6 addresses are still used, but only as names for topological locations in the network. HIP can be deployed such that no changes are needed in applications or routers. Almost all pre-compiled legacy applications continue to work, without modifications, for communicating with both HIP-enabled and non-HIP-enabled peer hosts. The architectural enhancement implemented by HIP has profound consequences. A number of the previously hard networking problems become suddenly much easier. Mobility, multi-homing, and baseline end-to-end security integrate neatly into the new architecture. The use of cryptographic identifiers allows enhanced accountability, thereby providing a base for easier build up of trust. With privacy enhancements, HIP allows good location anonymity, assuring strong identity only towards relevant trusted parties. Finally, the HIP protocols have been carefully designed to take middle boxes into account, providing for overlay networks and enterprise deployment concerns. This article provides an in-depth look at HIP, discussing its architecture, design, benefits, potential drawbacks, and ongoing work.

Abstract — This paper proposes a name service called name directory announcing the information of neighbors who are reachable in IPv6 mobile ad hoc network partition. Neighbor information consists of ad hoc user profile, DNS name and IPv6 address. Through name directory, ad hoc users can know who is reachable in the connected network partition and connect to the user’s mobile node with host DNS name. I.

This specification defines how HTTP Digest Authentication [Digest] can be used as a SASL [RFC 2222] mechanism for any protocol that has a SASL profile. It is intended both as an improvement over CRAM-MD5 [RFC 2195] and as a convenient way to support a single authentication mechanism for web, mail, LDAP, and other protocols.