RFC Abstracts

This document discusses options and requirements for the PDF rendering of RFCs in the RFC Series, as outlined in RFC 6949. It also discusses the use of PDF for Internet-Drafts, and available or needed software tools for producing and working with PDF.
In 2013, after a great deal of community discussion, the decision was made to shift from the plain-text, ASCII-only canonical format for RFCs to XML as the canonical format with more human-readable formats rendered from that XML. The high-level requirements that informed this change were defined in RFC 6949, "RFC Series Format Requirements and Future Development". Plain text remains an important format for many in the IETF community, and it will be one of the publication formats rendered from the XML. This document outlines the rendering requirements for the plain-text RFC publication format. These requirements do not apply to plain-text RFCs published before the format transition.
The HTML format for RFCs assigns style guidance to a Cascading Style Sheet (CSS) specifically defined for the RFC Series. The embedded, default CSS as included by the RFC Editor is expected to take into account accessibility needs and to be built along a responsive design model. This document describes the requirements for the default CSS used by the RFC Editor. The class names are based on the classes defined in "HTML for RFCs" (RFC 7992).
In order to meet the evolving needs of the Internet community, the canonical format for RFCs is changing from a plain-text, ASCII-only format to an XML format that will, in turn, be rendered into several publication formats. This document defines the HTML format that will be rendered for an RFC or Internet-Draft.
This document defines the "xml2rfc" version 3 vocabulary: an XML-based language used for writing RFCs and Internet-Drafts. It is heavily derived from the version 2 vocabulary that is also under discussion. This document obsoletes the v2 grammar described in RFC 7749.
In order to improve the readability of RFCs while supporting their archivability, the canonical format of the RFC Series will be transitioning from plain-text ASCII to XML using the xml2rfc version 3 vocabulary; different publication formats will be rendered from that base document. With these changes comes an increase in complexity for authors, consumers, and the publisher of RFCs. This document serves as the framework that provides the problem statement, lays out a road map of the documents that capture the specific requirements, and describes the transition plan.
This document describes an end-to-end session identifier for use in IP-based multimedia communication systems that enables endpoints, intermediary devices, and management systems to identify a session end-to-end, associate multiple endpoints with a given multipoint conference, track communication sessions when they are redirected, and associate one or more media flows with a given communication session. While the identifier is intended to work across multiple protocols, this document describes its usage in the Session Initiation Protocol (SIP).
RFCs 6513, 6514, and other RFCs describe procedures by which a Service Provider may offer Multicast VPN (MVPN) service to its customers. These procedures create point-to-multipoint (P2MP) or multipoint-to-multipoint (MP2MP) trees across the Service Provider's backbone. One type of P2MP tree that may be used is known as an "Ingress Replication (IR) tunnel". In an IR tunnel, a parent node need not be directly connected to its child nodes. When a parent node has to send a multicast data packet to its n child nodes, it does not use Layer 2 multicast, IP multicast, or MPLS multicast to do so. Rather, it makes n individual copies, and then unicasts each copy, through an IP or MPLS unicast tunnel, to exactly one child node. While the prior MVPN specifications allow the use of IR tunnels, those specifications are not always very clear or explicit about how the MVPN protocol elements and procedures are applied to IR tunnels. This document updates RFCs 6513 and 6514 by adding additional details that are specific to the use of IR tunnels.
Corruption of the Remaining Lifetime field in a Link State Protocol Data Unit (LSP) can go undetected. In certain scenarios, this may cause or exacerbate flooding storms. It is also a possible denial-of-service attack vector. This document defines a backwards-compatible solution to this problem.
This document defines a set of new properties for iCalendar data and extends the use of some existing properties to the entire iCalendar object.
This document analyzes security threats to Simplified Multicast Forwarding (SMF), including vulnerabilities of duplicate packet detection and relay set selection mechanisms. This document is not intended to propose solutions to the threats described.
RFC 3263 defines how a Session Initiation Protocol (SIP) implementation, given a SIP Uniform Resource Identifier (URI), should locate the next-hop SIP server using Domain Name System (DNS) procedures. As SIP networks increasingly transition from IPv4-only to dual-stack, a quality user experience must be ensured for dual- stack SIP implementations. This document updates the DNS procedures described in RFC 3263 for dual-stack SIP implementations in preparation for forthcoming specifications for applying "Happy Eyeballs" principles to SIP.
This document defines how Datagram Transport Layer Security (DTLS), Real-time Transport Protocol (RTP), RTP Control Protocol (RTCP), Session Traversal Utilities for NAT (STUN), Traversal Using Relays around NAT (TURN), and ZRTP packets are multiplexed on a single receiving socket. It overrides the guidance from RFC 5764 ("SRTP Extension for DTLS"), which suffered from four issues described and fixed in this document.
A host with multiple interfaces needs to choose the best interface for communication. Oftentimes, this decision is based on a static configuration and does not consider the path characteristics, which may affect the user experience.
This document defines a new optional Intermediate System to Intermediate System (IS-IS) TLV named CAPABILITY, formed of multiple sub-TLVs, which allows a router to announce its capabilities within an IS-IS level or the entire routing domain. This document obsoletes RFC 4971.
Complexity is a widely used parameter in network design, yet there is no generally accepted definition of the term. Complexity metrics exist in a wide range of research papers, but most of these address only a particular aspect of a network, for example, the complexity of a graph or software. While it may be impossible to define a metric for overall network complexity, there is a desire to better understand the complexity of a network as a whole, as deployed today to provide Internet services. This document provides a framework to guide research on the topic of network complexity as well as some practical examples for trade-offs in networking.
The U.S. National Telecommunications and Information Administration (NTIA) solicited a request from the Internet Corporation for Assigned Names and Numbers (ICANN) to propose how the NTIA should end its oversight of the Internet Assigned Numbers Authority (IANA) functions. After broad consultations, ICANN in turn created the IANA Stewardship Transition Coordination Group. That group solicited proposals for the three major IANA functions: names, numbers, and protocol parameters. This document contains the IETF response to that solicitation for protocol parameters. It was included in an aggregate response to the NTIA alongside those for names and numbering resources that are being developed by their respective operational communities. A reference to that response may be found in the introduction, and additional correspondence is included in the Appendix.
The IETF TRILL (Transparent Interconnection of Lots of Links) protocol includes an optional mechanism (specified in RFC 7178) called RBridge Channel for the transmission of typed messages between TRILL switches in the same campus and the transmission of such messages between TRILL switches and end stations on the same link. This document specifies extensions to the RBridge Channel protocol header to support two features as follows: (1) a standard method to tunnel payloads whose type can be indicated by Ethertype through encapsulation in RBridge Channel messages; and (2) a method to support security facilities for RBridge Channel messages. This document updates RFC 7178.
The WebSocket protocol enables two-way real-time communication between clients and servers in situations where direct access to TCP and UDP is not available (for example, from within JavaScript in a web browser). This document specifies a new WebSocket subprotocol as a reliable transport mechanism between Message Session Relay Protocol (MSRP) clients and relays to enable usage of MSRP in new scenarios. This document normatively updates RFCs 4975 and 4976.
The Third Generation Partnership Project (3GPP) has identified cases where different SIP private header extensions referred to as "P-" header fields, and defined in RFC 7315, need to be included in SIP requests and responses currently not allowed according to RFC 7315. This document updates RFC 7315, in order to allow inclusion of the affected "P-" header fields in such requests and responses.
The Request Routing interface comprises (1) the asynchronous advertisement of footprint and capabilities by a downstream Content Delivery Network (CDN) that allows an upstream CDN to decide whether to redirect particular user requests to that downstream CDN; and (2) the synchronous operation of an upstream CDN requesting whether a downstream CDN is prepared to accept a user request and of a downstream CDN responding with how to actually redirect the user request. This document describes an interface for the latter part, i.e., the CDNI Request Routing Redirection interface.
Recent RFCs have discussed issues with host identification in IP address-sharing systems, such as address/prefix-sharing devices and application-layer proxies. Potential solutions for revealing a host identifier in shared address deployments have also been discussed. This memo describes the design, deployment, and privacy considerations for one such solution in operational use on the Internet today that uses a TCP option to transmit a host identifier.
When carried over Layer 2 technologies such as Ethernet, IPv6 datagrams using Low-Power Wireless Personal Area Network (LoWPAN) encapsulation as defined in RFC 4944 must be identified so the receiver can correctly interpret the encoded IPv6 datagram. The IETF officially requested the assignment of an Ethertype for that purpose and this document reports that assignment.
Entertainment Identifier Registry (EIDR) Identifiers are used for the globally unique identification of motion picture and television content. This document defines the formal Uniform Resource Name (URN) Namespace Identifier (NID) for EIDR Identifiers.
Many Internet applications are used to access resources such as pieces of information or server processes that are available in several equivalent replicas on different hosts. This includes, but is not limited to, peer-to-peer file sharing applications. The goal of Application-Layer Traffic Optimization (ALTO) is to provide guidance to applications that have to select one or several hosts from a set of candidates capable of providing a desired resource. This memo discusses deployment-related issues of ALTO. It addresses different use cases of ALTO such as peer-to-peer file sharing and Content Delivery Networks (CDNs) and presents corresponding examples. The document also includes recommendations for network administrators and application designers planning to deploy ALTO, such as recommendations on how to generate ALTO map information.
The Incident Object Description Exchange Format (IODEF) defines a data representation for security incident reports and indicators commonly exchanged by operational security teams for mitigation and watch and warning. This document describes an updated information model for the IODEF and provides an associated data model specified with the XML schema. This new information and data model obsoletes RFCs 5070 and 6685.
DHCP servers have evolved over the years to provide significant functionality beyond that described in the DHCP base specifications. One aspect of this functionality is support for context-specific configuration information. This memo describes some such features and explains their operation.
TRILL (Transparent Interconnection of Lots of Links) uses distribution trees to deliver multi-destination frames. Multiple trees can be used by an ingress Routing Bridge (RBridge) for flows, regardless of the VLAN, Fine-Grained Label (FGL), and/or multicast group of the flow. Different ingress RBridges may choose different distribution trees for TRILL Data packets in the same VLAN, FGL, and/or multicast group. To avoid unnecessary link utilization, distribution trees should be pruned based on one or more of the following: VLAN, FGL, or multicast destination address. If any VLAN, FGL, or multicast group can be sent on any tree, for typical fast-path hardware, the amount of pruning information is multiplied by the number of trees, but there is limited hardware capacity for such pruning information.
There can be machine-to-machine (M2M) scenarios where server responses to client requests are redundant. This kind of open-loop exchange (with no response path from the server to the client) may be desired to minimize resource consumption in constrained systems while updating many resources simultaneously or performing high-frequency updates. CoAP already provides Non-confirmable (NON) messages that are not acknowledged by the recipient. However, the request/response semantics still require the server to respond with a status code indicating "the result of the attempt to understand and satisfy the request", per RFC 7252.
This specification specifies requirements for providing Diameter security at the level of individual Attribute-Value Pairs (AVPs).
Many transport services require that user traffic, in the form of Pseudowires (PWs), be delivered via either a single co-routed bidirectional tunnel or two unidirectional tunnels that share the same routes. This document defines an optional extension to the Label Distribution Protocol (LDP) that enables the binding between PWs and the underlying Traffic Engineering (TE) tunnels. The extension applies to both single-segment and multi-segment PWs.
Routing information reduction by BGP Route Reflection or Confederation can result in persistent internal BGP route oscillations with certain routing setups and network topologies. This document specifies two sets of additional paths that can be used to eliminate these route oscillations in a network.
RFCs 4328 and 7139 provide signaling extensions in Resource ReserVation Protocol - Traffic Engineering (RSVP-TE) to control the full set of Optical Transport Network (OTN) features. However, these specifications do not cover the additional Optical channel Data Unit (ODU) containers defined in G.Sup43 (ODU1e, ODU3e1, and ODU3e2). This document defines new Signal Types for these additional containers.
This document presents a taxonomy of a set of "Alternative Network Deployments" that emerged in the last decade with the aim of bringing Internet connectivity to people or providing a local communication infrastructure to serve various complementary needs and objectives. They employ architectures and topologies different from those of mainstream networks and rely on alternative governance and business models.
This document specifies a TRILL (Transparent Interconnection of Lots of Links) IS-IS application sub-TLV that enables the reporting by a TRILL switch of sets of addresses. Each set of addresses reports all of the addresses that designate the same interface (port) and also reports the TRILL switch by which that interface is reachable. For example, a 48-bit MAC (Media Access Control) address, IPv4 address, and IPv6 address can be reported as all corresponding to the same interface reachable by a particular TRILL switch. Such information could be used in some cases to synthesize responses to, or bypass the need for, the Address Resolution Protocol (ARP), the IPv6 Neighbor Discovery (ND) protocol, or the flooding of unknown MAC addresses.
Domain-based Message Authentication, Reporting, and Conformance (DMARC) introduces a mechanism for expressing domain-level policies and preferences for email message validation, disposition, and reporting. However, the DMARC mechanism enables potentially disruptive interoperability issues when messages do not flow directly from the author's administrative domain to the final Recipients. Collectively, these email flows are referred to as "indirect email flows". This document describes these interoperability issues and presents possible methods for addressing them.
The Constrained Application Protocol (CoAP) is a RESTful transfer protocol for constrained nodes and networks. Basic CoAP messages work well for small payloads from sensors and actuators; however, applications will need to transfer larger payloads occasionally -- for instance, for firmware updates. In contrast to HTTP, where TCP does the grunt work of segmenting and resequencing, CoAP is based on datagram transports such as UDP or Datagram Transport Layer Security (DTLS). These transports only offer fragmentation, which is even more problematic in constrained nodes and networks, limiting the maximum size of resource representations that can practically be transferred.
The root zone of the Domain Name System (DNS) has been cryptographically signed using DNS Security Extensions (DNSSEC).
RFC 5727 defined several processes for the former Real-time Applications and Infrastructure (RAI) area. These processes include the evolution of the Session Initiation Protocol (SIP) and related protocols, as well as the operation of the DISPATCH and SIPCORE working groups. This document updates RFC 5727 to allow flexibility for the area and working group structure, while preserving the SIP change processes. It also generalizes the DISPATCH working group processes so that they can be easily adopted by other working groups.
The base TRILL (Transparent Interconnection of Lots of Links) protocol provides optimal pair-wise data frame forwarding for Layer 2 intra-subnet traffic but not for Layer 3 inter-subnet traffic. A centralized gateway solution is typically used for Layer 3 inter-subnet traffic forwarding but has the following issues:
This document proposes a framework for the management of the Locator/ ID Separation Protocol (LISP) Endpoint Identifier (EID) address block. The framework described relies on hierarchical distribution of the address space, granting temporary usage of prefixes of such space to requesting organizations.
This document directs IANA to allocate a /32 IPv6 prefix for use with the Locator/ID Separation Protocol (LISP). The prefix will be used for local intra-domain routing and global endpoint identification, by sites deploying LISP as Endpoint Identifier (EID) addressing space.
This document specifies a new iCalendar (RFC 5545) component that allows the publication of available and unavailable time periods associated with a calendar user. This component can be used in standard iCalendar free-busy lookups, including the iCalendar Transport-independent Interoperability Protocol (iTIP; RFC 5546) free-busy requests, to generate repeating blocks of available or busy time with exceptions as needed.
This document defines a YANG extension that allows for defining metadata annotations in YANG modules. The document also specifies XML and JSON encoding of annotations and other rules for annotating instances of YANG data nodes.
This document defines encoding rules for representing configuration data, state data, parameters of Remote Procedure Call (RPC) operations or actions, and notifications defined using YANG as JavaScript Object Notation (JSON) text.
YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF).
This document defines a mechanism to use IPv4 to transport OSPFv3 packets. Using OSPFv3 over IPv4 with the existing OSPFv3 Address Family extension can simplify transition from an OSPFv2 IPv4-only routing domain to an OSPFv3 dual-stack routing domain. This document updates RFC 5838 to support virtual links in the IPv4 unicast address family when using OSPFv3 over IPv4.
The popularity of Internet Exchange Points (IXPs) brings new challenges to interconnecting networks. While bilateral External BGP (EBGP) sessions between exchange participants were historically the most common means of exchanging reachability information over an IXP, the overhead associated with this interconnection method causes serious operational and administrative scaling problems for IXP participants.
This document outlines a specification for multilateral interconnections at Internet Exchange Points (IXPs). Multilateral interconnection is a method of exchanging routing information among three or more External BGP (EBGP) speakers using a single intermediate broker system, referred to as a route server. Route servers are typically used on shared access media networks, such as IXPs, to facilitate simplified interconnection among multiple Internet routers.
GeoJSON is a geospatial data interchange format based on JavaScript Object Notation (JSON). It defines several types of JSON objects and the manner in which they are combined to represent data about geographic features, their properties, and their spatial extents. GeoJSON uses a geographic coordinate reference system, World Geodetic System 1984, and units of decimal degrees.