IPoC: A New Core Networking Protocol for 5G Networks
5G is the latest iteration of cellular network technology developed to meet the growing traffic demand for both smartphones and homes. With beamforming and frequency bands reaching millimeter waves, 5G promises many benefits:
- Higher speeds
- Lower latency
- The ability to connect many more devices
However, current de jure standards and protocols, designed for earlier technologies, have the potential to dilute these promises. To address the limitations of current networks, CableLabs developed the IP over CCN (IPoC) protocol, a compelling new solution to meet the new, more robust requirements of 5G.
Why a New Solution?
The primary goal of the fourth generation (4G or LTE) technology was access to the Internet, so the technology utilized IP networking, the packet routing technology historically and currently used in the Internet.
IP networking has been around since the mid-1970s and has served us remarkably well, but it isn’t without flaws. The purpose of the Internet Protocol is to allow a computer at one fixed location in the network to exchange information with another computer at a fixed location in the network. For mobile devices (that clearly aren’t at a fixed location) this has never been a great fit, and LTE technology had to develop complicated IP over IP tunneling mechanisms (the LTE Evolved Packet Core (EPC)) to enable mobility.
Furthermore, in the majority of cases, a mobile application wants to fetch specific data (say the text and images of a blog post) but doesn’t really care which computer it talks to in order to get it. As a result, to improve network efficiency and performance, network operators (both mobile and fixed) have implemented complex Content Distribution Networks in order to try to redirect the mobile application to the nearest server or cache that has the requested data.
In LTE-EPC, all of a user’s IP traffic is tunneled through a centralized choke point (or anchor) in the mobile operator’s core network, which eliminates the ability to serve data from a nearby cache. Also, as a mobile device moves in the network, the EPC needs to create new tunnels and tear down old ones in order to ensure that the user’s data reaches them.
These limitations are widely acknowledged by standards-setting groups. They are currently soliciting input to introduce new protocols that will pave the way for 5G to meet the demands of next-generation technologies, specifically:
- Improve the efficiency and performance of the network mobility plane, compared to today’s LTE standards,
- Support non-IP network protocols, of which Content Centric Networking is a leading candidate.
Benefits of Content Centric Networking
Content Centric Networking: A networking paradigm that emphasizes content by making it directly addressable and routable. Learn more here.
CCN offers several key advantages over IP networking:
- It employs “stateful forwarding” which elegantly and efficiently supports information retrieval by mobile client devices without the need for tunneling or a location registration protocol
- It addresses content directly rather than addressing end hosts, which means that it enables in-network caching, processing and intelligent packet forwarding, allowing it to excel in content retrieval optimization, allowing data to be easily retrieved from an on-path cache
- It supports a client device using multiple network attachments (e.g., radio links) simultaneously, providing greater reliability and performance.
- Its design meets the needs of large-data and IoT applications
For many new applications, CCN provides a much better fit for purpose than the Internet Protocol.
IP over CCN (IPoC): A New Way to Handle IP
In spite of the significant improvements Content Centric Networking offers over current IP networking, the reality is that all of today’s applications, both client and server, are built to use IP networking. We developed IPoC as the solution to this issue. IP over CCN (IPoC) protocol is a general-purpose tunneling protocol that enables delivery of IP traffic over a Content Centric Network (CCN) or a Named Data Network (NDN).
IPoC enables deployment of CCN as the core networking protocol for 5G, both for new, native CCN applications and as a mobility plane for existing IP applications, replacing the LTE-EPC. As a result, IPoC saves the IP investment and allows a full transition to the new CCN protocol.
With this approach:
- Native CCN applications reap the benefits of tunnel-free anchorless networking, along with the latency and efficiency gains that come from in-network caching.
- Existing IP-based applications can be supported with a mobility management solution that is simpler than the existing LTE-EPC. Gone are the special-purpose tunnel management functions that create and destroy tunnels as mobile devices move in the network.
- The need for network slicing to accommodate both IP and CCN and the complications and overhead entailed in running two core networks in parallel are eliminated.
IPoC Performance in Mobile Networks
With the assistance of two PhD students from Colorado State University, we developed simulation models and conducted performance and efficiency testing of the protocol in comparison to LTE-EPC. In our simulation study, we implemented the IPoC protocol using the Named Data Networking (NDN) simulator ndnSim (which implements a CCN-like semantic) and used mobile communication as the driving example, comparing IPoC-over-NDN protocol performance against GTP-over-IP. We found that the protocol overhead and performance impact of IPoC is minimal, which makes it suitable for immediate deployment. The report on this study includes links to the source code as well.
Want to Take a Closer Look?
IPoC can be best understood as a transition technology. Providing a shim layer and allowing CCN to act as a mobility plane for legacy IP applications, it accommodates the current protocol standards while opening the door for deployment of native CCN applications and the benefits they offer.
The 5G standardization project is seeking new mobility solutions for 5G, and we believe CCN and IPoC would be a great solution to address the needs. We have submitted a definition of the IPoC protocol as an Internet-Draft to the Internet Research Task Force (IRTF) Information Centric Networking Research Group. In addition, we have developed a proof-of-concept implementation of the IPoC protocol on Linux.
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Re-Inventing the Internet
The Internet Protocol – IP. It has become practically synonymous with networking, and over the last 40 years the adoption of IP has radically changed the world economy and the way that people interact globally, with CableLabs and the cable industry being a major force in that adoption. The past 15+ years in particular have been marked by the transitioning of the significant majority of industries, services, and human interactions into versions that are mediated by the world wide web, itself built on the foundation of the Internet Protocol. As this transition has taken place, the way that we use the network has radically evolved, from a simple point-to-point (or end-to-end) model with static endpoints, into one of massively distributed computing and storage accessed almost entirely by a huge number of mobile and nomadic client devices (with content and virtualized services being deployed on demand wherever it is most advantageous).
Alongside this usage evolution, network engineers have evolved in the way that they build IP networks, constructing ever more complex systems to try to manage the flow of communication, and have even taken on a change of the IP protocol (from IPv4 to IPv6) in an attempt to solve its most pressing shortcoming, the size of the address space. However, it is becoming more apparent that the address space issue is not the only problem with IP, and that we may be nearing the day when a more fundamental re-invention is needed.
A New Approach to Networking
Information Centric Networking is an emerging networking approach that aims to address many of the shortcomings inherent in the existing Internet Protocol. The field of Information Centric Networking was sparked by work at Stanford University in 1999-2002, which proposed a radical re-thinking of the network stack and a fundamental change in the way information flows in the global data network. Since that time, a number of researchers have developed proposals for the operational model, semantics, and syntax of an Information Centric Network, and today, one technology appears to be leading the pack and to be poised for potential success. This approach to Information Centric Networking, being developed in parallel by two projects: Content-Centric Networking (CCN) and Named Data Networking (NDN), appears to be gaining mindshare in the research community and in industry, and promises to significantly improve network scalability and performance, and reduce cost over a network built on the Internet Protocol. CCN/NDN provides native, and elegant, support for client mobility, multipath connectivity, multicast delivery and in-network caching, many of which are critical for current and future networks, and all of which require inefficient and/or complex managed overlays when implemented in IP. Further, CCN/NDN provides a much richer addressing framework than that which exists in IP (which could eliminate significant sources of routing complexity), and it provides a fundamentally more secure communication model, even for in-the-clear communications.
By moving away from a "host-centric" view of networking functions, where the core protocol (IP) is entirely devoted to delivering data from one specific host to another, to a "content-centric" view, where content objects are identified and routed solely by the use of globally unique names, the CCN/NDN approach provides a more elegantly scalable, faster, and more efficient network infrastructure for the majority of traffic on the Internet today. To get a sense of how big a mind shift this is, consider this: in CCN/NDN devices don’t have addresses at all. A device can retrieve content by requesting it by name, without needing to have a way of identifying a server where that content is stored, or even identifying itself.
At CableLabs, we are experimenting with this new protocol and are deep into investigating the applications that might drive its adoption. Because CCN/NDN is built with mobility, privacy and efficient content distribution in mind from the beginning, we see synergies with the direction that cable networks are going. We see this as enabling a convergence of fixed networking, mobile networking and content distribution – a “Fixed-Mobile-Content Convergence”.
As IP is baked into the networking field (equipment, software stacks, applications, services, engineering knowledge, business models, even national policies), it may seem daunting to consider the use of a non-IP protocol. However, while IP has been a phenomenally successful networking protocol for the last 40 years, as technology and time inevitably marches on it is reasonable to believe that we won’t be utilizing it forever. And furthermore, while replacing IP with another protocol will certainly bring implementation challenges, it doesn’t follow that doing so necessarily means changing the way applications and users interact with the network. In other words, the web will still look and act like the web, but it will become more streamlined and efficient.
To be clear, CCN/NDN is not a mature protocol ready for immediate deployment. A number of R&D issues are still being worked in academic and industry research groups (including CableLabs), and implementations (both endpoint stacks and network gear) are still largely in the reference implementation or proof-of-concept stage. However, development work is active and confidence is high that the protocol will be ready for deployment in the next 3-5 years.
As part of this investigation, CableLabs has released a publication describing how an existing Content Distribution Network (CDN) evolves to one that leverages the benefits of CCN.
Greg White is a Distinguished Technologist at CableLabs.
Good-Bye IPv4, Hello IPv6
ARIN just ran out of IPv4 addresses!
News sources are abuzz that ARIN has finally ran out of IP addresses. Let’s take a look at the implications.
Q: What is ARIN?
A: ARIN is the American Registry of Internet Numbers serving North America and is one of five official entities that can issue IPv4 addresses to Internet Service Providers, government agencies, enterprises and small companies. There are only five of these issuing entities that serve the entire world – and here is a map, showing the areas served:
Figure 1 Taken from Wikipedia – https://en.wikipedia.org/wiki/Regional_Internet_registry
Four of the five Regional Internet Registries (RIRs) have exhausted their pools of IPv4 addresses, meaning that it will become increasingly difficult for Internet Service Providers to acquire additional IPv4 addresses to support growth in subscribers, services, and devices.
Q: So, how does a lack of IPv4 addresses affect me as an ordinary person?
A: Every device that communicates over the Internet has been using an IPv4 IP address for messages, music, videos, and tweets. Home Wi-Fi routers, computers, laptops, smart phones and tablets all need an IP address, and now, home security systems, home automation systems, home entertainment systems, smart thermostats, smart locks, smart watches and other new generation devices all need IP addresses, too. Running out of IPv4 address space means there are no more IPv4 addresses available to assign to new devices. Therefore, those devices will need to share addresses in order to connect to the public Internet. Imagine “party line service” when you are watching cat videos on new devices from YouTube!
Internet Service Providers (ISPs) have been working vigorously over the last several years to migrate their networks to the IPv6 protocol. All this time that IPv4 devices in the home have been working, the world has been silently but steadily changing. To that point, CableLabs incorporated IPv6 in the DOCSIS® cable modem standard ten years ago and now cable companies lead the world in the scope of IPv6 deployments. Internet Service Providers that do not soon support IPv6 may begin to share IPv4 addresses, and this can impact some services such as gaming and Voice over IP. IPv4-only support will slowly decline as IPv6 adoption increases during a long migration period. Eventually, all devices connected to the Internet will support IPv6.
ISPs are prepared to support IPv4/IPv6 co-existence for many years to come. The reason is that most web and video content today is still primarily IPv4, and this is largest area holding back an IPv6 enabled world. Slowly, more and more web and video sites are migrating to IPv6 but it will take time for all content to be provided on IPv6.
There are still millions of IPv4-only capable devices in the world, particularly consumer electronics products such as smart TVs, video streaming devices, and gaming consoles. It will take time for these products to adopt support for IPv6. However, many traditional computing devices today, such as smart phones, laptops and tablets already support both IPv4 and IPv6.
Q: Why is IPv6 a better solution? Is it just because it has more addresses than IPv4?
A: IPv6 has many new features that make it superior to IPv4 which will include:
• IPv6 has so many IP addresses that conserving them or running out of them will not be a concern. The entire IPv4 address space has a little over 4-billion addresses. By contrast, the smallest IPv6 block allocation has enough addresses for 18 million-trillion devices. This is great news when considering that the Internet of Things (IoT) will make enormous demands for new IP addresses. IPv6 will be able to easily accommodate not only this exponential growth, but also much more for generations to come.
• IPv6 has generally proven to be 8% to 15% faster than IPv4. One of the reasons is that unique IPv6 addresses are plentiful and every device in the home can get one for pure end-to-end communications, whereas using scarce IPv4, devices in homes share the same address space because there are not enough addresses. These shared addresses have to be converted to a unique address at the home router before going to the Internet – and this conversion takes time.
• Operational Efficiency. IPv6 has no broadcast messages. A broadcast is a message that is sent to all devices on the same network. This means that all devices have to take the time to accept and interpret the broadcast message, even though the broadcast message is meant for only one device. Because IPv6 has no broadcast messages, it saves bandwidth, time and processing power.
Q: Will I have to replace IPv4 devices in my home?
A: Chances are good that many recently purchased devices such as laptops, home routers, smart phones, and tablets most likely support both IPv4 and IPv6. Many other devices such as TVs can continue to use IPv4, but will not be able to communicate with IPv6-only content providers. To facilitate the transition to IPv6,
CableLabs offers IPv6 certification testing for home routers and the equipment used inside cable companies to ensure IPv6 interoperability between equipment, products and services.
You can test any device for IPv6 connectivity by going to test-ipv6.com. This web site will tell you if your ISP is providing your home network with an IPv4 or an IPv6 address, or both.
IPv4 has delivered us this far for today’s IP world. Looking forward, IPv6 is a solid answer to growing needs of IP addresses, speed, security, efficiency and operational ease, and CableLabs will ensure compliance and interoperability to speed the migration toward IPv6.
Die gracefully, IPv4. Rock-on, IPv6!