Why information centric networking

ICN may provide opportunities for better cache coordination and global management of the storage resources of multiple caches. On the other hand, once a named data object exists in multiple caches, consistent and coherent update semantics and supporting protocols have to be defined, dealing with, e.

With ICN, new security models are needed. Moreover, not all objects will be universally accessible, requiring authorization and scoping mechanisms. The ICN paradigm is also expected to require new interfaces for applications to interact with the network. For example, a new API should let application developers take advantage of location-independent naming, caching, and multi-access functionality in ICN. It is expected that ICN will require changes to the business, legal and regulatory landscape.

An ICN approach potentially has better energy efficiency than existing approaches, because data is transported, on average, over shorter distances.

While more cache storage has to be powered in the network, even that might be energy-efficient, because the cooling load can be better distributed to more, but smaller installations. ICN has the potential to improve relevant metrics like invested energy per user-perceived latency. Migration and interworking possibilities are also required to foster large-scale experiments and thorough evaluation of ICN concepts and specific concrete approaches. The development of corresponding testbeds and experimentation facilities is potentially an important activity area of the ICNRG.

The ICNRG will produce a document that provides guidelines for experimental activities in the area of ICN so that different, alternative solutions can be compared consistently, and information sharing accomplished for experimental deployments.

The ICNRG provides a forum for the exchange and analysis of ICN research ideas and proposals; work that is based on implementation experiences is given preference. The group holds regular physical meetings at least once a year in conjunction with IETF meetings. Additional meetings are held at IETF or other venues, such as in conjunction with related academic conferences. In addition, such documentation could become input to IETF working groups.

Attention will be given to avoiding overlaps with existing IETF work while informing the work with the results of ongoing research. In this paper, the many important concepts in ICN are discussed, which include the different architectures and projects surrounding ICN. Challenges will also be discussed related to naming, routing, and caching in Information-Centric Networking. With a growing society comes a need for growth in technology as well. In particular, the demand for mobile data traffic is growing exponentially and will soon surpass what can be supplied with the traditional host-centric architecture.

The Cisco Visual Networking Index forecast predicts that by the year , mobile and wireless devices will account for 71 percent of the total IP traffic, which leads to a sevenfold increase in mobile data traffic globally between and [CISCO19]. Part of the cause for mobile data traffic growth is the rising use of video traffic.

By , 82 percent of all IP traffic will be IP video traffic, which will be a fourfold increase from These demands are being attempted to be met by many architectures, with the main one being the Content Delivery Network CDN. CDN is a network that is not scalable to the growth of users and will be a problem in the near future. A promising solution to the problems of legacy networks leaves the traditional host-centric end-to-end communication behind, such as CDN, and takes a more information-centric approach.

This was the beginning of the concept of ICN [Cheriton00]. ICN is based on a receiver-driven content retrieval model, where the traditional host-based IP addresses are replaced by an information-based scheme [Fang18]. The user will retrieve information based on the requested content and not based on a specific location. This paper will introduce the concept of ICN, as well as the history of multiple ICN projects that have been proposed over the years. This will also include the different challenges the paradigm faces in terms of naming, routing, cache, security, mobility, and applications.

Information-Centric Networks uses a new internet communication approach that is data-oriented and does not focus on who is delivering its contents. Since this scheme is data-based, the paradigm relies on content naming to create an ICN, as well as routing and caching like in traditional networks. To fully understand what the benefits of ICN are, one must know the difference between the traditional networks and ICN. CDN is one of the main network architectures currently in use.

The basic concept of CDN is having a network of servers close to the network edge with up to date content to optimize availability and latency [Sarkar16]. Not only is this relating to mobile devices, but the increase in IoT devices will add additional difficulty to the performance and reliability of the CDNs. In CDN, a user may enter a web address in their browser, such as www. Although, if the edge server does not have the data that has been requested, it will redirect the request to the original server and cache the response for later requests.

The usefulness of this paradigm depends on the storage space and the rate of requests, as well as the uniqueness of the requests. The traditional network consists of hosts being named by their IP addresses, which is based on their location in the network.

Therefore, since the name is bound to the address, and the address is based on location, the address will change when the physical location is changed. With a rise in mobile devices, this will be an increasing problem. With ICN, this is no longer a problem, because ICN does not request content based on the address of the host, but rather based on the content itself.

Instead of needing to know a host, in ICN, just the name of the content will do. There are many approaches to retrieving data in a name-based manner, which differs from the traditional architecture by not requiring a host's IP address to obtain content. This approach eliminates identification and location as the primary parameters when requesting data. To use the naming scheme, various parameters determine if the naming scheme is efficient enough. These are split into primary and secondary parameters.

The primary parameters consist of identification, routing assistance, readability, security, and scalability [Krishna19]. Identification , also known as uniqueness, means that the naming scheme has to provide a unique name to all content that is not the same. This is to prevent collision with the contents being requested by a user. Routing Assistance refers to the naming scheme making the data objects routable.

In a network where content is requested based on content names, without contacting a server, the content will need to be easily reachable. Readability pertains to the need for humans to be able to read the name of the content the user is querying. The naming scheme should, therefore, provide a name that is readable to a human as well as descriptive of what the contents hold.

Security is an important factor to verify the contents requested. The naming scheme will have to certify the data objects through self-certification or attestation by a third party.

This is so that the user can authenticate the contents it requested without it being corrupted or falsified. Scalability is one of the most important requirements of a naming scheme. The move from the traditional host-centric network to a receiver-driven network is precisely because of scalability issues with more mobile data traffic. If the naming scheme is not scalable, staying with CDN might be the better option.

The secondary parameters consist of name resolution, implementation complexity, caching effect, the effect on existing names, naming scheme translation ease, and ease of addition of existing content [Krishna19]. Name Resolution relates to the primary parameter of readability. Content should be able to be identified by its name. Depending on the naming scheme, the lookup that maps the name to the data object might differ. Implementation Complexity refers to compatibility with legacy architectures.

The naming scheme must be complex enough to implement the new paradigm, but not complex enough to not work along with traditional networks.

The caching effect in a naming scheme goes hand-in-hand with various caching schemes in ICNs. To improve efficiency in a network, caching is an important factor and extensive research is being done, which is beyond the scope of this paper. Since the naming scheme is a major factor in caching, it needs to be helping and not hurt the caching techniques.

The effect on existing names should be flawless. Multiple naming schemes should be able to coexist in a network without causing conflicts.

This includes legacy networks as well as different ICN naming schemes. Since these schemes will need to coexist, another parameter, naming scheme translation ease , is an important factor for naming schemes to be able to translate easily between each other.

Ease of addition of existing content to a new naming scheme is very important. Content that is currently uploaded needs to be able to be used in an ICN and might be a challenge since it cannot be removed. There are many factors to take into consideration when choosing or creating a naming scheme, and there are trade-offs, which results in multiple different schemes. The naming schemes to identify content in ICNs are categorized as follows: flat naming, hierarchical naming, attribute-based naming, and hybrid naming.

Flat Naming uses a cryptographic hash function to create a flat content identifier [Koponen07]. In flat naming, a string consisting of multiple characters is created and used as the output of the hash function, which is a globally unique principal field, P.

This is then put together in a P : L form. Hierarchical Naming consists of concatenating multiple components, after which a unique identifier can be created and assigned. This is very similar to the structure of Uniform Resource Identifiers URI , which means that the current mechanisms for handling IP addresses can easily be made to handle hierarchical names.

This format also makes it more user-friendly and is scalable because names can be aggregated [Dannewitz10]. Attribute-Based Naming does not request content by a name as the other two naming schemes but instead uses attribute-value pairs AVP to identify contents. Hybrid Naming is an attempt at an all-benefit solution to naming schemes. It tries to take advantage of each of the other three naming schemes and make the disadvantages have a lesser impact [Zhang14].

In this naming scheme, the first part of the name will be hierarchical, and the second part of the name will be flat naming. Then the third part will add attributes to the name based on the attribute-based naming scheme.

Having the first part hierarchical gives the benefit of easier aggregations, while flat naming of the second part will limit the length, which improves query speed for length-based algorithms. Multiple projects have been in the works over the years, focusing on efficient ICNs, which includes efficient naming schemes. Table 1 [Krishna19] illustrates the different advantages and disadvantages of each naming scheme that contributes to the decision of what scheme to use in various ICN architectures.

Flat, hierarchical, attribute-based, and hybrid naming schemes cannot just be chosen based on their benefits by themselves, but one must also consider how these naming schemes affect the routing in the network.

In an ICN, the requested content is requested by name and will, therefore, need to be routed to the correct place. Since the requester does not know the location of the contents, efficient routing has to be done, and the network will need an existing knowledge of where valid copies of the content are. Therefore, there are four important characteristics regarding content or name-based routing: content-oriented, robustness, efficiency, and scalability [Velloso13].

With these characteristics, intuitively it is known that packets should not have any location information; routing should quickly recover from faults, control information should have low impact, and routing should work well in all scenarios and topologies, respectively. These are the characteristics, but the properties of routing mechanisms that are important to keep in mind, although outside the scope of this paper, are: scalability, content state, discovery of closest copy, resolution and retrieval locality, discovery guarantee, network-level deployment, and security.

The ICN routing techniques can also be grouped into two categories: non-hierarchical and hierarchical routing. Non-Hierarchical Routing does not have any structures in place to store routing information and is, therefore, also referred to as unstructured routing.

The routing information would have to be calculated at each node as the packets flow through the network. Hierarchical Routing , as the name suggests, organizes the routers in a hierarchical structure, and this hierarchical relationship can be used to have a deterministic flow of data going through the network. Therefore, hierarchical routing is also referred to as structured routing. In ICN, there are two main architectures of hierarchical routing, which are tree-based and distributed hash tables DHT.

DHT uses a hash table that is distributed among the nodes in the network and provides an efficient way for routing by making queries for cryptographic keys in an overlay network [Ganesan04]. Tree-based topologies need knowledge of affiliation, parity, superiority or inferiority to determine the location of the desired destination node. This is done by having parent nodes act as gateway nodes between their children.

The request only goes up to the highest hierarchical level it needs to, based on the subtree the destination node belongs to. The efficiency and safety of routing are very important and limiting the amount of routing that needs to be done will ultimately help with those characteristics. One way to limit the amount of routing is by caching. Caching in ICN is a key component since it will limit how far requests will need to go.

In the traditional CDNs, caching is based on content popularity, which means that if there is a large amount of request for certain content, it will be cached closer to the edge of the network.

ICN uses local information alone to determine what to cache. Any node in the network can act as an edge-node cache at any time, which means that the existing network can be made into content distribution networks since the content requests do not rely on location or host. In the previous section, multiple components of ICNs were discussed. The differences in all these schemes are put together in many different ways, which is why multiple projects have risen to improve the concept of having an efficient content-based network.

It allowed for better naming support and opened the door for future development. Many new projects followed suit over the years, both U. The U. Although these architectures all bring different elements to the table, many are evolving from an older project into newer projects. With DONA, information availability increases since it is not relying on just one host to provide the contents. As mentioned, DONA uses a flat naming scheme which consists of a cryptographic hash of the publisher's key, as well as an object ID assigned by the publisher.

The name is unique within the domain of the publisher. It is suggested that publishers use a hash of the object as the identifier.