Monthly Archives: June 2017

5G and Internet Technology

5G is the latest generation of cellular network standards. There’s a tremendous amount of activity around it in the industry. But how does 5G relate to Internet technology? Are there 5G-related work items that the IETF should be working on, for instance?

While at times the 5G stories take on an almost myth-like nature, the basics underneath 5G are concrete changes in the technology and our increasing needs for communication. The traffic growth for both our smartphones and homes continues to be exponential. And as organisations and societies increasingly connect their systems, there are also many new needs.

5G responds to these needs with new radio technology and a core network that employs state-of-the-art network technologies such as an increased use of cloud, virtualisation, and open source components and processes. From a standards perspective, the timelines for the first systems are very near. The 5G work happens to a large extent in 3GPP, as did previous generations. The work on 5G is planned to take place in two releases, of which the first one is Release 15, scheduled to be stable and all protocols completed latest by September 2018, just 14 months away. Additional work will be done in Release 16, which will complete by March 2020.

What is 5G?

But what exactly is 5G then? First, it is a new, very capable radio. With beamforming, MIMO antenna technology, and frequency bands reaching to millimeter waves, it provides both higher transmission speeds and serves more users at the same time. The new radio is also needed to serve mass deployment of networked sensors, and to enable various mission-critical services that may require better latency or reliability characteristics. 5G radio can provide speeds in the Gigabit range, up to 10 Gbps or even beyond, although for large numbers of users the speeds are lower, but still target at least tens of megabits per user, for tens of thousands of users.

Second, 5G targets a set of use cases, such as the familiar mobile broadband use case. But 5G is also intended to open the use of communication and cellular networks for many new industries. The goal is to be able to tailor communication platform for a wide range of different services, ranging from low power IoT devices to self-driving
cars, from mission critical public safety communication to providing services to energy providers. any of these use cases were hard to provide with previous generation technologies. For instance, one use case is about controlling remote machinery — an example of a service that benefits from lower latencies that 5G provides. There is also a higher demand on flexibility and configurability/orchestration.

From an IP networking perspective, as noted, 5G follows the same evolution as the rest of the networking industry. From a practical perspective, this is a big change, however, and requires effort. The work on details is ongoing for Release 15, but architecturally, the key directions are clear.

To give a few practical examples, interfaces to the devices are relatively similar to those in 4G. One difference is an ability to place different devices in different virtual networks or “slices”, which can be tuned and evolve independently from each other, both in resources and networking technology behind. Another difference to 4G is that the 3GPP security group plans to enable a more flexible authentication framework for the devices. And some of the control protocols inside the network may be changed from DIAMETER-based ones to REST-based APIs. From what we understand, the tunneling-based architecture for mobility is not changing, but of course with most services being provided in virtualised environments, the tunnel endpoints may physically reside in different places.

It should also be said that 5G is not a replacement for Internet-based services or Internet technology: majority of the traffic that 5G will carry is for the usual Internet services, like videos from content providers. 5G is also not immune to impacts from Internet evolution. For instance, we’ve seen big changes in use of encryption in the Internet, transport protocols are evolving, the use of CDN systems is growing, and all networks are becoming virtualised, software-defined, and cloud-resident systems. 5G networks need to serve the Internet that continues to evolve in this manner.

Is there an IETF connection?

It is useful to understand how 5G affects Internet technology. IETF work has been and will be affected by 5G. To begin with, the IETF works on many of the general facilities that modern networked systems such as 5G are based on.

Conceptually, one can think of the interactions as falling in the following categories:

  • New dependencies on existing IETF technology. For instance, the flexible authentication framework mentioned above is EAP (RFC 3748, RFC 5448). This is likely to be merely a reference to existing RFCs, or if additions are needed, they are small.
  • Dependencies to ongoing work at the IETF. This includes various general facilities as noted above, but also other things. For instance, the IETF DETNET working group defines mechanisms to guarantee deterministic delays for some flows across a network. As one of the 5G use cases is time-critical communication and low-latency applications, this is a component technology that is being looked at. Similarly, IETF routing-related work such as traffic engineering, service chaining and source routing are likely tools in managing traffic flows in 5G networks.
  • Topics where there is clear demand for a feature, but it is unclear whether changes to Internet technology are needed, or the details remain to be determined. For instance, in the upcoming IETF meeting in Prague, we will be discussing whether some additional support is needed for what is in 5G called Network Slicing. There are many IETF tools, however, for dealing with virtualisation and separation of networks, so first order of business is probably mapping what can be done with those tools.
  • Larger, architectural changes, e.g., “future Internet” type solutions such as ICN (Information Centric Networking) are sometimes suggested also in the context of 5G. While these are perhaps unlikely in the first release of 5G, it is of course certain that the evolution of the Internet continues (and there will be future releases of 5G standards as well).

Going Forward

We asked Gonzalo Camarillo and Georg Mayer (liaisons between 3GPP and IETF) about collaboration between IETF and 3GPP. They said that our best approach is to ensure that the 3GPP engineers are involved in the IETF work they are interested in. And that 3GPP states clearly what their requirements (rather than solutions) are. They also noted that the work in 3GPP is ongoing. Hence completing protocol requirements for 5G will still take some time. Gonzalo and Georg will be contacting the relevant parties on both sides to keep us in sync.

Exchange of information would also benefit from informal collaboration, for instance through Internet technology experts working with the 3GPP community. This enables common topics to be easily discussed and brought forward.

We should also note that there are clear boundaries between the two organisations. The IETF works on Internet technologies which may or may not get used in different networks. 3GPP puts together systems, architectures, and designs protocols specific to their networks and layers. The IETF is not in charge of making system level or requirement decisions for the 3GPP. Similarly, 3GPP leaves the evolution of Internet protocols to the IETF.

Also, recently Alissa Cooper, Chair of the IETF, visited a 3GPP meeting. Her report is here.

Finally, it should be noted that many of the existing tussles in the Internet continue to exist with 5G. For instance, the ability to provide a highly dynamic and programmable radio environment continues to present opportunities for collaboration between networks and applications. Such collaboration is not something that has historically been easy in the Internet, however. When we discussed this as a part of the growing use of encryption, the necessary changes to network management practices due to the encryption changes caused pain for operators. Perhaps as some time has passed, and networks continue to evolve, we could consider network – application collaboration as an opportunity and ask what useful things networks can do for applications?

Jari Arkko, Ericsson, IAB Member
Jeff Tantsura, Consultant, IAB member
Image credits: Ericsson, 3GPP, IETF, and Wikipedia (Peter K Burian).

What does “Internet Access” mean?

On the joint day of the the recent IESG and IAB retreats, the group discussed a number of topics related to network operator activities for encrypted flows. As part of that conversation, the group looked at RFC 4084, which tackled the question what “Internet Access” means. A dozen years on, that subject probably deserves a new look, and several of the folks at the retreat agreed to draft a new version for community review.

As one of those volunteers, I’d like to dive into RFC 4084 a bit and explore what may have changed since it was published. After walking through the need to avoid pejorative terms, the RFC sets out the following types of connectivity: web connectivity; client connectivity only with no public address; client connectivity only with a public address; firewalled Internet connectivity; and full Internet connectivity.

For those who have bought enterprise connectivity recently, it’s obvious that several common categories are missing: dark fiber, lit service connectivity to a home office, managed MPLS tunnels, and so on. More importantly, though, the RFC doesn’t really touch on cellular wireless connectivity at all, which is now one of the most common ways people connect to the Internet. That means that it doesn’t touch on topics like data caps, roaming for data services, zero rating, or data compression proxies. For cellular connectivity, those can be the key to understanding the trade-offs in connectivity, privacy, and costs for a particular service offering.

Beyond that proliferation in available offerings, there has been another major change, in the ubiquity of filtering. RFC 4084 describes filtering at the ISP level in section 3 and notes “the effort to control or limit objectionable network traffic has led to additional restrictions on the behavior and capabilities of internet services”. RFC 7754 has since provided a much more detailed description of blocking and filtering, and it highlights restricting objectionable content as a category beyond blocking objectionable traffic. That blocking may be a requirement imposed by state regulators. In those jurisdictions, what RFC 4084 described as “full Internet connectivity” has disappeared, because service providers are required to prevent their customers from reaching specific Internet resources, services, or destinations. Even where blocks are not in place, regulatory increases in the amount of Internet tracking data retained and the length of time it is kept have become common. These may contribute to self-censorship in the use of some content. Put simply, firewalled Internet connectivity has become the default offering required of service providers within those territories.

Lastly, the document describes Internet connectivity in terms that apply to the services which would be consumed by a human user and, though some social networking or streaming services are not included, it is generally useful in that regard. As we move into an era in which devices talk to other devices, we also need to examine what a service provides for traffic among devices or between devices and back-end services. Is the implication of a web-only service that the Internet of Things is not supported, or is the implication that it must be reached by a web-based gateway or proxy? The difference between those two is a serious topic of contemplation now, and the architecture of a number of services will depend on it.

In many cases, the architecture of the Internet has developed in the course of a commercial dialog between network operators’ offerings and consumers’ use. Many efforts to make cellular systems walled gardens failed, for example, because the users simply weren’t willing to use them that way and wanted the broader connectivity of the Internet. As we look at this new tension among users’ desires for confidential communication, network operators’ management practices, and regulatory frameworks, a common vocabulary for the services available to the user may help us understand what architectures we can build. If you’d like to contribute to the early discussion, architecture-discuss@iab.org is one place to start.

Ted Hardie
IAB

Working Together with 3GPP on 5G

3GPP Meeting June 2017Last week I had the opportunity to participate at the 3GPP plenary meeting in West Palm Beach, Florida, USA, at the invitation of the 3GPP liaison to the IETF, Georg Mayer. In addition to attending meetings of 3GPP’s radio access network group and system architecture group, I had the chance to kick off their new “Wednesday Speaker Club” series with a discussion of how 3GPP and the IETF can cooperate on 5G standardization.

The push towards the next generation of wireless networking technology has been gaining increasing attention and spurring new work across the industry, SDOs, and open source projects. 3GPP participants are investing tremendous effort to define and prioritize 5G requirements to help bring this technology to fruition. They are also working against very tight timelines, with the initial set of 5G standards due to be completed by June 2018. It is therefore both timely and important to identify whether dependencies between 5G and IETF work exist, as well as to identify mechanisms to ensure smooth collaboration.

The IETF and 3GPP have a long history of working together and many successes to build on, including our experience with SIP/IMS, EAP-AKA, and Diameter. Because 5G encompasses a broader swath of folks than those who have been involved in previous joint efforts, I spent part of my time at the meeting introducing how the IETF works, our focus on broadly deployable internet technology, and what we work on. I highlighted some areas of existing IETF work that may be of relevance in the 5G context, including our work on data models, service chaining, deterministic networking, and QUIC (look for more details on these areas in a forthcoming blog post). And I engaged with 3GPP participants around specific strategies to help our two organizations collaborate. You can see my slides here.

The speaker club Q&A session focused on the potential and practicalities of improving collaboration. We talked about the need to have technical experts from each group engage directly with each other (in addition to our existing liaison managers working in both directions), opportunities to provide more introductory presentations in both directions so people not familiar with 5G or specific IETF work can learn more, and ways to identify potential 5G requirements that may yield IETF protocol dependencies early on, even if later analysis in 3GPP reduces the urgency of the need for IETF protocol work.

IETF 99 should serve as a useful opportunity to continue this dialogue and gain more clarity about what specific dependencies we might expect between the 5G plans and IETF work. As noted in my recent post about BOF proposals, we’ll have a slot on the agenda to discuss some of the network slicing work motivated by 5G, in addition to numerous hallway conversations and ad hoc discussions I’m sure. For those working on other aspects of 5G not covered in the BOF proposals and who may be looking for guidance or input about overlaps with IETF work, feel free to reach out to the IAB, the IESG, or our liaison to 3GPP, Gonzalo Camarillo, with questions and comments. Several of us have been working to understand the 5G requirements better and would be happy to hear from you.

Alissa Cooper
IETF Chair

New Work at Upcoming IETF 99 Meeting

Prague

Before each IETF meeting, the Internet Engineering Steering Group (IESG) collects proposals for new working groups. We decide which ones are ready for community discussion on the IETF meeting agenda, with input from the Internet Architecture Board (IAB). We did this last week in preparation for IETF 99 and I wanted to report the conclusions:

BANdwidth Aggregation for interNet Access (BANANA) will be having a working-group-forming Birds of a Feather (BOF) session at IETF 99. BANANA is concerned with providing coordinated Internet Access to a device over multiple links of different types to allow for increased bandwidth utilization, load-balancing and/or higher reliability. The goal of this BOF is to determine whether the scope of the problem is well defined and understood, whether there is a critical mass of participants willing to work on the problem, and whether in general the working group would have a reasonable probability of success if chartered. The BANANA mailing list is here.

IDentity Enabled Networks (IDEAS) will be having a working-group-forming BOF. The goal of this work is to standardize a framework that provides identity-based services that can be used by any identifier-location separation protocol. The new requirements driving this framework go beyond the traditional discovery service and mapping of identifier-to-location for packet delivery. The goal of the BOF is to identify what specific work items are appropriate for IETF standardization. The IDEAS mailing list is here.

Network Slicing (NETSLICING) will be having a non-working-group-forming BOF. In this work proposal, a “network slice” is conceptualized as a logical network comprised of the union of resources (connectivity, storage, computing), network functions, and service functions. Network slicing is a concept garnering much attention as part of 5G standardization and development efforts. The goal of the BoF is to identify whether a shared understanding exists of terminology, decomposition of the problem space, and relationships between the goals of the work and existing protocol work in other IETF working groups. Getting clarity on the priority of relevant requirements from 3GPP is also critical. The relevant mailing list is here.

We also received a proposal for a WG-forming BOF concerning 5G IP Access and Session Management Protocols (5GIP), which was not approved for this meeting cycle so as to provide more time for refinement. The responsible area director and others in the IESG and IAB who have been exploring the overlap between 5G and IETF work will continue to engage with the proponents to help gain more clarity, refine scoping, and understand overlaps with other SDOs.

Finally, we’ll have one newly chartered working group meeting for the first time at IETF 99: DKIM Crypto Update (DCRUP). The DCRUP working group is chartered to update DomainKeys Identified Mail (DKIM, RFC 6376) to handle more modern cryptographic algorithms and key sizes. The mailing list is here.

Looking forward to productive discussions in all these areas at IETF 99.

Alissa Cooper
IETF Chair

Increasing capabilities of advanced automatic crash notifications

This post is by Brian Rosen and Randall Gellens, participants in the ecrit working group.

A car crash on a country road.

Emergency calls placed by vehicles involved in a crash can provide significant benefit, especially when vehicle occupants are injured or unable to place a 9-1-1 call themselves. Sometimes called “Advanced Automatic Crash Notification” or “vehicle telematics”, the ability to automatically or manually place an emergency call when a vehicle is involved in a crash has been available for over two decades in the U.S., while the EU has a mandated system called “eCall” that is in the process of being deployed. Recently published IETF RFCs aim to expand the capabilities of such services, and to make them more broadly implementable.

Current U.S. systems are proprietary; some use non-standard in-band modems to send vehicle location and crash data from the vehicle to a call center, which then relays the information to the Public Safety Answering Point (PSAP, also known as an emergency call center). The relaying is done either by non-standard out-of-band data transmission or orally by a service center agent. Other systems place a 9-1-1 call, play a prerecorded message to the PSAP call taker, and use text-to-speech to convey vehicle location and sometimes crash data. The EU eCall system uses a standardized in-band modem to convey vehicle location and crash data from the vehicle to a specialized PSAP, which has a corresponding modem to receive the data.

The IETF has published two documents: RFC 8147 and RFC 8148 that specify how such calls operate using next-generation (all-IP) technology. Vehicles using these RFCs initiate emergency calls either manually or automatically in the event of a crash or other serious incident; the calls carry a standardized set of vehicle location and incident data. Such a call can be routed to a PSAP equipped for this, where the data can be automatically processed and displayed to a call taker at call assignment. During the call, the call taker can request that the vehicle send updated data or perform an action such as flashing its lights.

The IETF developed a generalized mechanism for making data related to an emergency call available to the PSAP along with the emergency call. This mechanism, called “Additional Data”, RFC 7852, allows standardized data “blocks” to be sent in a SIP (RFC 3261) call, either as data in the body of an INVITE message, or as a URL sent in the header which, when dereferenced, yields the data block. RFC 8148 defines a data block for the U.S. “Vehicle Emergency Data Set” developed by the Association of Public-Safety Communications Officials (APCO) and the National Emergency Number Association (NENA), while RFC 8147 defines a block for the eCall data set used in the EU. These RFCs also provide a mechanism for the call taker to request that the vehicle perform an action, such as honking the horn or flashing the lights to allow the responders to locate the vehicle.

– Brian Rosen and Randall Gellens

IETF Profile: Mirja Kühlewind

Periodic posts on the IETF Blog highlight individuals who serve in IETF leadership roles, people who have recently begun working in the IETF, and organizations that make the work of the IETF possible. Each post aims to describe experiences working within or supporting the IETF. This one is by Mirja Kühlewind, who is an IETF Transport Area Director. You can also see her interview here.

Mirja Kühlewind, IETF Transport Area Director at IETF 98.

Mirja Kühlewind, IETF Transport Area Director at IETF 98.

I first got involved with the IETF when I started my PhD. A colleague, who was already involved pointed out that it was starting work closely related to my own interests. I attended my first IETF meeting in 2010, when the CONEX [Congestion Exposure] Working Group (WG) held a Birds-of-a-Feather meeting. From then on, it was my own initiative that kept me working with the IETF—I had support from my group, and they usually had enough travel budget for me to attend the meetings.

Three years ago, I became chair of the RMCAT [RTP Media Congestion Avoidance Techniques] Working Group. I only gave that up when I became Transport Area Director (AD). I also was chair of the TCPINC Working Group for half a year. So I became an AD just six years after starting to participate in the IETF.

There are a limited number of people involved in the Transport Area. As soon as I became more active, I was encouraged to take the role of a Working Group chair. Transport AD wasn’t an option until I finished my PhD. Ultimately, though, it worked out nicely because I got stable funding for a project for a little more than two years, which freed me up to consider the position.

The project is generally funded by the European Union, with additional funding by Switzerland for my part, which includes work we planned to bring into the IETF. This would have allowed me to justify spending so much of my time on IETF work. However, since the project funding is coupled to certain research goals, I additionally contacted some companies and they provide support for some of my time and travel budget.

I hope that my experience as AD can count as management experience and that people value it. It’s a good way to improve your skills because you are in a management position where you don’t have any power, but you need to motivate people. For me, it is about how well I manage Working Groups and how well I manage my time. I spend 40% of my time on my AD work and 60% on my research project. It can be a challenge to balance them.

I don’t think that ETH directly benefits from me being Transport AD. But they did get external funding for our project, and that funding had a strong focus on making an impact on industry. So my standardization work may have helped to get the project funded. I don’t think I needed a leadership role for that. Being a Working Group chair was probably enough to show that I had IETF experience, but my AD role of course also makes a good impression.

Everybody’s biggest concern about taking on an IETF leadership role is time management. I do it on a 40% basis. It’s a little stressful, yes, but it is possible. The other reason it’s hard to find people for the Transport AD role is that the right person not only needs support, money, and time for the IETF, but also must have an overview about what’s going on in Transport. I was in the unique position that I was following the same Working Groups that I now carry as AD—it’s no extra effort.

I don’t have a plan yet for when my term is over, but I know I’d like to stay involved in the IETF. When my ETH project is finished, I’ll be a four-year post doc. I’ll need to make a decision about whether to stay in academics or go into industry. If I apply for a job next year, I won’t stand as Transport AD—I can’t ask a new employer to let me spend 40% of my time on the IETF. Even as a professor, it would be hard for me to get 40% of my time off for the IETF.

It’s been an interesting experience, particularly because I’m just starting my career. I’ve learned a lot, and I’ve made a lot of industry contacts that I’ve gotten to know well. I’m grateful—the IETF as a community has provided me with networking opportunities and a source of ideas for research.