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We propose 4+4, a simple address extension architecture for Internet that provides an evolutionary approach to extending the existing IPv4 address space in comparison to more complex and disruptive approaches best exemplified by IPv6 deployment. The 4+4 architecture leverages the existence of Network Address Translators (NATs) and private address r...
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Context 1
... private realms connect to the public realm via NATs. Figure 1 shows a typical network scenario assumed by 4+4. The "grey colored" networks belong to the public address realm and each "white colored" network represents a separate private realm. ...
Context 2
... Figure 1 private realm A and B are connected to the public net- work 2 via realm gateways with public addresses A and B, respec- tively. These addresses are separate from the address pool assigned for the address translation function. ...
Context 3
... figure also shows four hosts, two in the public realm (nodes C and D) and two in private address realms (nodes X and Y). IPv4 addresses in the public realm are called level 1 addresses (ad- dresses A, B, C and D in Figure 1), while addresses in private realms are called level 2 addresses (X and Y). In the remainder of this paper bold capitals are used to denote 32-bit IPv4 addresses and the nodes having those addresses. ...
Context 4
... routers inside private address realms are configured with the routing information for both private and public addresses; that is, they know how to route toward both level 1 and level 2 destina- tions. For example, assume that node D in network 6 posts a packet to node C in network 2, as illustrated in Figure 1. The packet uses public source and destination addresses and is delivered unaltered to the destination through the routers and realm gateways of net- work 3. ...
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This article presents the simulation of an IPv4 network connected to two IPv6 isles. Those protocols are not compatible; therefore, transition mechanisms were implemented to fulfill a fundamental role. Meanwhile, this reaches the total deployment of IPv6, such as: Tunneling and Address translation. The first, encapsulates an IPv6 packet inside an I...
Citations
... 4+4 [24]: A 4+4 extended address is formed by concatenating a 32-bit public address with a 32-bit private address. They are also called "level 1" and "level 2" ...
One of the major challenges in the evolution of the Internet architecture is the definition of a protocol architecture that allows to solve the following major issues in Internet routing and traffic forwarding capabilities, (i) keeping a routing state that is manageable with current and forthcoming computing infrastructure – i.e., with few millions of states, (ii) offering a scalable pull architecture in support of data-plane programmability, (iii) offering a scalable forwarding plane able to be regularly optimized with only active flows information, (iv) offering locator/identifier separation for advanced IP mobility, (v) is incrementally deployable, (vi) can enhance the support of over-the-top services. The Locator/Identifier Separation Protocol (LISP) has been identified as one of the rising protocols in this respect. In its current status, it supports the above mentioned requirements at a level that is acceptable for basic networking environments. However, it shows too limited capacities when it comes to take into consideration fault resiliency and capability to react fast to network state updates. These shortcomings can be compensated by enhancing the control-plane architecture, and the routing algorithms therein. In this dissertation, we propose new protocol features and experiment novel control-plane primitives, as well as hybrid distributed-centralized routing state dissemination algorithms, to scale with different network conditions. We first design and build own open source LISP data-plane and control plane node, comparing it with other implementations, showing how our implementation can scale for large networks and reach performances suitable for real deployments. We present how our implementation served to operate all network nodes (data-plane and control-plane nodes) of a large scale experimentation testbed, the LISP-Lab testbed. Then we propose a novel LISP-based solution for VM live migrations across geographically separated datacenters over wide area IP networks. Experimenting it at large scale, we show that with our approach we can easily reach sub-second downtimes upon Internet-wide migration, even for very distant clients. Moreover, we investigate cross-layer network optimization protocols, in particular in relation with the Multipath Transport Control Protocol (MPTCP) to which LISP can deliver path diversity in support of bandwidth increase, confidentiality support and connection reliability, also using LISP traffic engineering network overlays. Despite we could benefit from only few overlay network nodes, we could experimentally evaluate our proposals showing the positive impact by using our solution, the negative impact of long round-trip times on some MPTCP subflows, and the strong correlation between the differential round-trip time among subflows and the throughput performance. Finally, we worked on a framework to improve LISP operation at the Internet scale, by facilitating cooperation between LISP Mapping Systems and introducing more automation in the LISP connectivity service delivery procedure. We believe such optimization could raise awareness among the service providers’ community, yielding new business opportunities related to LISP mapping services and the enforcement of advanced inter-domain traffic engineering policies for the sake of better quality of service guarantees.
... 4+4 is an addressing architecture [36] that aims to extend the IPv4 address space while retaining the original endto-end semantics of the Internet. A 4+4 extended address is formed by concatenating a 32-bit public address with a 32-bit private address. ...
The TCP/IP architecture of the Internet was originally designed around the contemporary restrictions of large computers that were difficult to move around. However, electronics followed Moore’s law, resulting in cheaper and smaller electronics for consumers, and portable devices, such as laptops and cellular phones, became pervasive. Consequently, the original restriction on static hosts was no longer true even though is still present in the design of the TCP/IP networking stack. The TCP/IP stack remains still constrained by its original design, which was effectively a design compromise to make the addressing model simpler. As TCP connections are created based on the same addresses used by the underlying network layer, the connections break when the address changes or is removed. Thus, the TCP/IP architecture is challenged in the temporal dimension of addressing as it was designed to assume stable addresses. This is not only problematic from the viewpoint of initial connectivity but also critical in sustaining of active data flows. In this paper, we first outline the challenges related to the inflexible nature of the TCP/IP architecture resulting from the fact that the same namespace is shared between the transport and network layers. We then discuss existing solutions for these challenges that arise from the transient nature of addresses in the TCP/IP architecture. Finally, we perform a qualitative analysis of the solutions discussed in the paper.
... 2) 4+4: The 4+4 proposal [126], [136] extends the NAT architecture to enable end-to-end host transparency. 4+4 uses two name spaces in DNS: one is the private IP addresses of the end-host and the other is the public IP address of the NAT router responsible for the end-host. ...
... The host itself does not know all the possible addresses it has (when behind several routers) since it is only aware of its name. This type of design introduces overhead in packet processing; for instance, NAT routers need to maintain FQDN records per host [136]. ...
... Some proposals build upon current practices in the Internet architecture and implement extensions to NAT, to allow the support of multihoming and enable end-to-end communication. For instance, 4+4 [136] supports multiaddressing, but raises security concerns since it exposes private addresses in packets. Others, such as IP Next Layer (IPNL) [137] address security but disable the multihoming information on end-hosts (e.g., hosts do not know if they have multiple addresses). ...
IP multihoming is a networking concept with a deceptively simple definition in theory. In practice, however, multihoming has proved difficult to implement and optimize for. Moreover, it is a concept, which, once adopted in the core Internet architecture, has significant impact on operation and maintenance. A trivial definition of multihoming would state that an end-node or an end-site has multiple first-hop connections to the network. In this chapter, we survey and summarize in a comprehensive manner recent developments in IP multihoming. After introducing the fundamentals, we present the architectural goals and system design principles for multihoming, and review different approaches. We survey multihoming support at the application, session, transport, and network layers, covering all recent proposals based on a locator-identifier split approach. We critically evaluate multihoming support in these proposals and detail recent developments with respect to multihoming and mobility management.
... Finally, MDCM is proposed as a model to describe generic multi-hop, multi-layer communication with a generic set of operations rather than a virtual layer connecting different networks as stated by Plutarch. 4+4 [21] is similar to Plutarch, but is limited in the network layer (IP) to bridge multiple NAT regions. Realm-Specific IP (RSIP) [1] is also based on the concept of regions, but uses tunneling across non-native regions rather than translating packets at the waypoints or gateways on the borders. ...
This paper presents an architectural model called the Multi-Domain Communication Model (MDCM) to describe the relationship between protocol layers, network hops and regions of multi-hop, multi-layer communication systems. MDCM treats communication processes as a series of recursive domain conversions and propagation within each domain. The concept of domain is a generalization of protocol layers and transit hops. MDCM includes end point resolution to map source and destination from one domain to the other, such as name/address resolutions, forwarding lookups, and content searching. MDCM integrates these aspects of communication processes and abstracts the core functionality into a simple, recursive model. It can describe a wide range of communication systems, and provide a new way of thinking regarding communication processes and system architecture designs.
... But Plutarch does not consider mobility of end hosts between multiple contexts andüberhoming and¨andüberhoming. IPNL [9] and 4+4 [10] try to isolate independent IP-based networks through loose integration. IPNL provides three stage communication path consisting of originating and terminating private realms and a global middle realm. ...
Network virtualization has been propounded as an open and flexible future internetworking paradigm that allows multiple virtual networks (VNs) to co-exist on a shared physical substrate. Each VN in a network virtualization environment (NVE) is free to implement its own naming, addressing, routing, and transport mechanisms. While such flexibility allows fast and easy deployment of diversified applications and services, ensuring end-to-end communication and universal connectivity poses a daunting challenge. This paper advocates that effective and efficient management of heterogeneous identifier spaces is the key to solving the problem of end-to-end connectivity in an NVE. We propose iMark, an identity management framework based on a global identity space, which enables end hosts to communicate with each other within and outside of their own networks through a set of controllers, adapters, and well-placed mappings without sacrificing the autonomy of the concerned VNs. We describe the procedures that manipulate these mappings between different identifier spaces and provide performance evaluation of the proposed framework.
... Some of these projects focus on virtualization methods to separate router functionality or whole networks [2], [3]. Others discuss on a higher abstraction level how networks beyond IP can be built [4], [5], [6]. These papers discuss issues like naming and addressing or network pluralism in general. ...
A majority of network architectures aim at solving specific shortcomings of the original Internet architecture. While providing solutions for the particular problems, they often lack in flexibility and do not provide general concepts for future networking requirements. In contrast, we introduce a network architecture that aims to be versatile enough to serve as a foundation for the future Internet. The main pillars of our architecture are communication pivots called information dispatch points (IDPs) which embed the concept of modularity at all levels of the architecture. IDPs completely decouple functional entities by means of indirection thus enabling evolving protocol stacks. Our architecture also provides a consistent application programming interface (API) to access node-local or network-wide functionality. In addition to the description of this architecture, we report about a working prototype of the architecture and we give examples of its application.
... This translates into the current Internet architecture design making it inefficient to initiate communication with an arbitrary entity on the current Internet, unless that entity has a public IPv4 (or an IPv6) address. Several architectures have been proposed to solve the Internet addressing issue as in [17, 26, 20]. However, in these approaches and even when a public address is available, inefficient mobility management schemes prevail requiring centralized infrastructure and continuous end-to-end negotiations between the endpoints over a simple " core " . ...
The Internet Protocol (IP) is currently used to provide inter-networking among heterogeneous access networks. However, the evolution of and the innovation within these networks is greatly hindered by the geographical and topological rigidness of the protocol implementation that hinders the support for flexible unstructured communication paradigms. To broaden the user's innovation space and to efficiently embrace the characteristics of these emerging unstructured networks, clean-slate architectural approaches are being pursued. In this paper, we present the Persistent Identification and NeTworking research framework (PINT); an implementation of the Transient Network Architecture (TNA) currently being developed between the University of New Mexico and the Corporation for National Research Initiatives. PINT provides the research community with a modular and extensible set of networking components and primitives that enable novel research and experimentation atop a persistently identified networking platform. This technology provides a ground for inter-networking of heterogeneous communication networks where novel networking primitives are exposed through the Persistent Identification and Networking Layer (PINL), allowing mobile and stationary entities to communicate securely based on persistent identifiers that are location independent.
... Most of the latter two technologies are independent of applications. "4+4" is an address extension architecture proposed in [13]. It extends an IPv4 header to contain two types of addresses; namely, a global IP address of a home gateway and a private IP address of an IN. ...
On the Internet, it is not possible to initiate communication to internal nodes located behind a Network Address Translator (NAT) from external nodes. Therefore, we need to have a NAT traversal technology that can establish a connection between the external and internal nodes. Technologies thus far often depend on specific applications and their usage is rather limited. There are other methods which do not depend on any applications, but their efficiency for end-to-end communication is usually lowered quite a lot because they need a specific server that relays packets. This paper presents an external dynamic mapping method to solve such problems. We also define NAT-free (NAT-f) protocol to realize the method. A NAT mapping is created by a negotiation between an external node and a home gateway at the time when the external node initiates communication with an internal node. The kernel in the external node translates the address and the port number in the sending packet to a mapped-address. We have implemented and evaluated a trial system, and the results show that there is almost no performance degradation.
... Our research is focused on the architectural considerations, but applying the architecture to an existing protocol helps ensure that engineering considerations are also identified and resolved. Note that as well O'Dell's draft proposal from 1996, and the HIP work currently in progress, we are also grateful for the following work on network architectures within the research community (in no particular order): Nimrod [5], TurfNet [21], Layered Naming Architecture [3], 4+4 [24], Split Naming/Forwarding Architecture [18], FARA [6], Plutarch [8], i3 [23], IP Next Layer [13], Triad [4]. These works have helped greatly in our thinking to date. ...
Internet users seek solutions for mobility, multi-homing, support for localised address management (i.e. via NATs), and end-to-end security. Existing mobility approaches are not well integrated into the rest of the Internet architecture, instead primarily being sepa-rate extensions that at present are not widely deployed. Because the current approaches to these issues were developed separately, such approaches often are not harmonious when used together. Mean-while, the Internet has a number of namespaces, for example the IP address or the Domain Name. In recent years, some have pos-tulated that the Internet's namespaces are not sufficiently rich and that the current concept of an address is too limiting. One proposal, the concept of separating an address into an Identifier and a sepa-rate Locator, has been controversial in the Internet community for years. It has been considered within the IETF and IRTF several times, but always was rejected as unworkable. This paper takes the position that evolving the naming in the Internet by splitting the address into separate Identifier and Locator names can provide an elegant integrated solution to the key issues listed above, without changing the core routing architecture, while offering incremental deployability through backwards compatibility with IPv6.
... As a consequent, new routing and tunneling protocols that play the similar role as NAT are proposed. A few explicit identity-based routing mechanisms are known so far [11] [12] [13]. ...
The growth of IPv4 Internet has been facing the infamous IP address depletion barrier. In practice, typical IPv4 Internet edge networks can be expanded by incorporating private addresses and NAT devices.
In this paper, major limitations of NAT-expanded private networks are presented. Furthermore, a solution is proposed to encourage the mixed usage of private and public IP addresses in a single edge network domain. The solution comprises of two key ideas : super-subnet mask and shared NAT. Super-subnet mask removes the routing boundary between private and public hosts. Shared NAT saves public IP address resources by sharing them among several private networks. These ideas not only encourage the coexistence of heterogeneous address classes, but also lead to efficient sharing of global IP addresses.
