RFC Abstracts

RFC8688 - A Session Initiation Protocol (SIP) Response Code for Rejected Calls
This document defines the 608 (Rejected) Session Initiation Protocol (SIP) response code. This response code enables calling parties to learn that an intermediary rejected their call attempt. No one will deliver, and thus answer, the call. As a 6xx code, the caller will be aware that future attempts to contact the same User Agent Server will likely fail. The initial use case driving the need for the 608 response code is when the intermediary is an analytics engine. In this case, the rejection is by a machine or other process. This contrasts with the 607 (Unwanted) SIP response code in which a human at the target User Agent Server indicates the user did not want the call. In some jurisdictions, this distinction is important. This document also defines the use of the Call-Info header field in 608 responses to enable rejected callers to contact entities that blocked their calls in error. This provides a remediation mechanism for legal callers that find their calls blocked.
RFC8687 - OSPF Routing with Cross-Address Family Traffic Engineering Tunnels
When using Traffic Engineering (TE) in a dual-stack IPv4/IPv6 network, the Multiprotocol Label Switching (MPLS) TE Label Switched Path (LSP) infrastructure may be duplicated, even if the destination IPv4 and IPv6 addresses belong to the same remote router. In order to achieve an integrated MPLS TE LSP infrastructure, OSPF routes must be computed over MPLS TE tunnels created using information propagated in another OSPF instance. This issue is solved by advertising cross-address family (X-AF) OSPF TE information.
RFC8686 - Application-Layer Traffic Optimization (ALTO) Cross-Domain Server Discovery
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. ALTO is realized by a client-server protocol. Before an ALTO client can ask for guidance, it needs to discover one or more ALTO servers that can provide suitable guidance.
RFC8685 - Path Computation Element Communication Protocol (PCEP) Extensions for the Hierarchical Path Computation Element (H-PCE) Architecture
The Hierarchical Path Computation Element (H-PCE) architecture is defined in RFC 6805. It provides a mechanism to derive an optimum end-to-end path in a multi-domain environment by using a hierarchical relationship between domains to select the optimum sequence of domains and optimum paths across those domains.
RFC8684 - TCP Extensions for Multipath Operation with Multiple Addresses
TCP/IP communication is currently restricted to a single path per connection, yet multiple paths often exist between peers. The simultaneous use of these multiple paths for a TCP/IP session would improve resource usage within the network and thus improve user experience through higher throughput and improved resilience to network failure.
RFC8683 - Additional Deployment Guidelines for NAT64/464XLAT in Operator and Enterprise Networks
This document describes how Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers (NAT64) (including 464XLAT) can be deployed in an IPv6 network -- whether it's cellular ISP, broadband ISP, or enterprise -- and the possible optimizations. This document also discusses issues to be considered when having IPv6-only connectivity, such as: a) DNS64, b) applications or devices that use literal IPv4 addresses or non-IPv6-compliant APIs, and c) IPv4-only hosts or applications.
RFC8682 - TinyMT32 Pseudorandom Number Generator (PRNG)
This document describes the TinyMT32 Pseudorandom Number Generator (PRNG), which produces 32-bit pseudorandom unsigned integers and aims at having a simple-to-use and deterministic solution. This PRNG is a small-sized variant of the Mersenne Twister (MT) PRNG. The main advantage of TinyMT32 over MT is the use of a small internal state, compatible with most target platforms that include embedded devices, while keeping reasonably good randomness that represents a significant improvement compared to the Park-Miller Linear Congruential PRNG. However, neither the TinyMT nor MT PRNG is meant to be used for cryptographic applications.
RFC8681 - Sliding Window Random Linear Code (RLC) Forward Erasure Correction (FEC) Schemes for FECFRAME
This document describes two fully specified Forward Erasure Correction (FEC) Schemes for Sliding Window Random Linear Codes (RLC), one for RLC over the Galois Field (a.k.a., Finite Field) GF(2), a second one for RLC over the Galois Field GF(2), each time with the possibility of controlling the code density. They can protect arbitrary media streams along the lines defined by FECFRAME extended to Sliding Window FEC Codes. These Sliding Window FEC Codes rely on an encoding window that slides over the source symbols, generating new repair symbols whenever needed. Compared to block FEC codes, these Sliding Window FEC Codes offer key advantages with real-time flows in terms of reduced FEC-related latency while often providing improved packet erasure recovery capabilities.
RFC8680 - Forward Error Correction (FEC) Framework Extension to Sliding Window Codes
RFC 6363 describes a framework for using Forward Error Correction (FEC) codes to provide protection against packet loss. The framework supports applying FEC to arbitrary packet flows over unreliable transport and is primarily intended for real-time, or streaming, media. However, FECFRAME as per RFC 6363 is restricted to block FEC codes. This document updates RFC 6363 to support FEC codes based on a sliding encoding window, in addition to block FEC codes, in a backward-compatible way. During multicast/broadcast real-time content delivery, the use of sliding window codes significantly improves robustness in harsh environments, with less repair traffic and lower FEC-related added latency.
RFC8679 - MPLS Egress Protection Framework
This document specifies a fast reroute framework for protecting IP/MPLS services and MPLS transport tunnels against egress node and egress link failures. For each type of egress failure, it defines the roles of Point of Local Repair (PLR), protector, and backup egress router and the procedures of establishing a bypass tunnel from a PLR to a protector. It describes the behaviors of these routers in handling an egress failure, including local repair on the PLR and context-based forwarding on the protector. The framework can be used to develop egress protection mechanisms to reduce traffic loss before global repair reacts to an egress failure and control-plane protocols converge on the topology changes due to the egress failure.
RFC8678 - Enterprise Multihoming using Provider-Assigned IPv6 Addresses without Network Prefix Translation: Requirements and Solutions
Connecting an enterprise site to multiple ISPs over IPv6 using provider-assigned addresses is difficult without the use of some form of Network Address Translation (NAT). Much has been written on this topic over the last 10 to 15 years, but it still remains a problem without a clearly defined or widely implemented solution. Any multihoming solution without NAT requires hosts at the site to have addresses from each ISP and to select the egress ISP by selecting a source address for outgoing packets. It also requires routers at the site to take into account those source addresses when forwarding packets out towards the ISPs.
RFC8677 - Name-Based Service Function Forwarder (nSFF) Component within a Service Function Chaining (SFC) Framework
Adoption of cloud and fog technology allows operators to deploy a single "Service Function" (SF) to multiple "execution locations". The decision to steer traffic to a specific location may change frequently based on load, proximity, etc. Under the current Service Function Chaining (SFC) framework, steering traffic dynamically to the different execution endpoints requires a specific "rechaining", i.e., a change in the service function path reflecting the different IP endpoints to be used for the new execution points. This procedure may be complex and take time. In order to simplify rechaining and reduce the time to complete the procedure, we discuss separating the logical Service Function Path (SFP) from the specific execution endpoints. This can be done by identifying the SFs using a name rather than a routable IP endpoint (or Layer 2 address). This document describes the necessary extensions, additional functions, and protocol details in the Service Function Forwarder (SFF) to handle name-based relationships.
RFC8676 - YANG Modules for IPv4-in-IPv6 Address plus Port (A+P) Softwires
This document defines YANG modules for the configuration and operation of IPv4-in-IPv6 softwire Border Relays and Customer Premises Equipment for the Lightweight 4over6, Mapping of Address and Port with Encapsulation (MAP-E), and Mapping of Address and Port using Translation (MAP-T) softwire mechanisms.
RFC8675 - A YANG Data Model for Tunnel Interface Types
This document specifies the initial version of a YANG module "iana-tunnel-type", which contains a collection of IANA-maintained YANG identities used as interface types for tunnel interfaces. The module reflects the "tunnelType" registry maintained by IANA. The latest revision of this YANG module can be obtained from the IANA website.
RFC8674 - The "safe" HTTP Preference
This specification defines a preference for HTTP requests that expresses a desire to avoid objectionable content, according to the definition of that term by the origin server.
RFC8673 - HTTP Random Access and Live Content
To accommodate byte-range requests for content that has data appended over time, this document defines semantics that allow an HTTP client and a server to perform byte-range GET and HEAD requests that start at an arbitrary byte offset within the representation and end at an indeterminate offset.
RFC8672 - TLS Server Identity Pinning with Tickets
Misissued public-key certificates can prevent TLS clients from appropriately authenticating the TLS server. Several alternatives have been proposed to detect this situation and prevent a client from establishing a TLS session with a TLS end point authenticated with an illegitimate public-key certificate. These mechanisms are either not widely deployed or limited to public web browsing.
RFC8671 - Support for Adj-RIB-Out in the BGP Monitoring Protocol (BMP)
The BGP Monitoring Protocol (BMP) only defines access to the Adj-RIB-In Routing Information Bases (RIBs). This document updates BMP (RFC 7854) by adding access to the Adj-RIB-Out RIBs. It also adds a new flag to the peer header to distinguish between Adj-RIB-In and Adj-RIB-Out.
RFC8670 - BGP Prefix Segment in Large-Scale Data Centers
This document describes the motivation for, and benefits of, applying Segment Routing (SR) in BGP-based large-scale data centers. It describes the design to deploy SR in those data centers for both the MPLS and IPv6 data planes.
RFC8669 - Segment Routing Prefix Segment Identifier Extensions for BGP
Segment Routing (SR) leverages the source-routing paradigm. A node steers a packet through an ordered list of instructions called "segments". A segment can represent any instruction, topological or service based. The ingress node prepends an SR header to a packet containing a set of segment identifiers (SIDs). Each SID represents a topological or service-based instruction. Per-flow state is maintained only on the ingress node of the SR domain. An "SR domain" is defined as a single administrative domain for global SID assignment.
RFC8668 - Advertising Layer 2 Bundle Member Link Attributes in IS-IS
There are deployments where the Layer 3 interface on which IS-IS operates is a Layer 2 interface bundle. Existing IS-IS advertisements only support advertising link attributes of the Layer 3 interface. If entities external to IS-IS wish to control traffic flows on the individual physical links that comprise the Layer 2 interface bundle, link attribute information about the bundle members is required.
RFC8667 - IS-IS Extensions for Segment Routing
Segment Routing (SR) allows for a flexible definition of end-to-end paths within IGP topologies by encoding paths as sequences of topological sub-paths, called "segments". These segments are advertised by the link-state routing protocols (IS-IS and OSPF).
RFC8666 - OSPFv3 Extensions for Segment Routing
Segment Routing (SR) allows a flexible definition of end-to-end paths within IGP topologies by encoding paths as sequences of topological subpaths called "segments". These segments are advertised by the link-state routing protocols (IS-IS and OSPF).
RFC8665 - OSPF Extensions for Segment Routing
Segment Routing (SR) allows a flexible definition of end-to-end paths within IGP topologies by encoding paths as sequences of topological subpaths called "segments". These segments are advertised by the link-state routing protocols (IS-IS and OSPF).
RFC8664 - Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing
Segment Routing (SR) enables any head-end node to select any path without relying on a hop-by-hop signaling technique (e.g., LDP or RSVP-TE). It depends only on "segments" that are advertised by link-state Interior Gateway Protocols (IGPs). An SR path can be derived from a variety of mechanisms, including an IGP Shortest Path Tree (SPT), an explicit configuration, or a Path Computation Element (PCE). This document specifies extensions to the Path Computation Element Communication Protocol (PCEP) that allow a stateful PCE to compute and initiate Traffic-Engineering (TE) paths, as well as a Path Computation Client (PCC) to request a path subject to certain constraints and optimization criteria in SR networks.
RFC8663 - MPLS Segment Routing over IP
MPLS Segment Routing (SR-MPLS) is a method of source routing a packet through an MPLS data plane by imposing a stack of MPLS labels on the packet to specify the path together with any packet-specific instructions to be executed on it. SR-MPLS can be leveraged to realize a source-routing mechanism across MPLS, IPv4, and IPv6 data planes by using an MPLS label stack as a source-routing instruction set while making no changes to SR-MPLS specifications and interworking with SR-MPLS implementations.
RFC8662 - Entropy Label for Source Packet Routing in Networking (SPRING) Tunnels
Segment Routing (SR) leverages the source-routing paradigm. A node steers a packet through an ordered list of instructions, called segments. Segment Routing can be applied to the Multiprotocol Label Switching (MPLS) data plane. Entropy labels (ELs) are used in MPLS to improve load-balancing. This document examines and describes how ELs are to be applied to Segment Routing MPLS.
RFC8661 - Segment Routing MPLS Interworking with LDP
A Segment Routing (SR) node steers a packet through a controlled set of instructions, called segments, by prepending the packet with an SR header. A segment can represent any instruction, topological or service based. SR allows enforcing a flow through any topological path while maintaining per-flow state only at the ingress node to the SR domain.
RFC8660 - Segment Routing with the MPLS Data Plane
Segment Routing (SR) leverages the source-routing paradigm. A node steers a packet through a controlled set of instructions, called segments, by prepending the packet with an SR header. In the MPLS data plane, the SR header is instantiated through a label stack. This document specifies the forwarding behavior to allow instantiating SR over the MPLS data plane (SR-MPLS).
RFC8659 - DNS Certification Authority Authorization (CAA) Resource Record
The Certification Authority Authorization (CAA) DNS Resource Record allows a DNS domain name holder to specify one or more Certification Authorities (CAs) authorized to issue certificates for that domain name. CAA Resource Records allow a public CA to implement additional controls to reduce the risk of unintended certificate mis-issue. This document defines the syntax of the CAA record and rules for processing CAA records by CAs.
RFC8658 - RADIUS Attributes for Softwire Mechanisms Based on Address plus Port (A+P)
IPv4-over-IPv6 transition mechanisms provide IPv4 connectivity services over IPv6 native networks during the IPv4/IPv6 coexistence period. DHCPv6 options have been defined to configure clients for Lightweight 4over6, Mapping of Address and Port with Encapsulation (MAP-E), Mapping of Address and Port using Translation (MAP-T) unicast softwire mechanisms, and multicast softwires. However, in many networks, configuration information is stored in an Authentication, Authorization, and Accounting (AAA) server, which utilizes the Remote Authentication Dial In User Service (RADIUS) protocol to provide centralized management for users. When a new transition mechanism is developed, new RADIUS attributes need to be defined correspondingly.
RFC8657 - Certification Authority Authorization (CAA) Record Extensions for Account URI and Automatic Certificate Management Environment (ACME) Method Binding
The Certification Authority Authorization (CAA) DNS record allows a domain to communicate an issuance policy to Certification Authorities (CAs) but only allows a domain to define a policy with CA-level granularity. However, the CAA specification (RFC 8659) also provides facilities for an extension to admit a more granular, CA-specific policy. This specification defines two such parameters: one allowing specific accounts of a CA to be identified by URIs and one allowing specific methods of domain control validation as defined by the Automatic Certificate Management Environment (ACME) protocol to be required.
RFC8656 - Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN)
If a host is located behind a NAT, it can be impossible for that host to communicate directly with other hosts (peers) in certain situations. In these situations, it is necessary for the host to use the services of an intermediate node that acts as a communication relay. This specification defines a protocol, called "Traversal Using Relays around NAT" (TURN), that allows the host to control the operation of the relay and to exchange packets with its peers using the relay. TURN differs from other relay control protocols in that it allows a client to communicate with multiple peers using a single relay address.
RFC8655 - Deterministic Networking Architecture
This document provides the overall architecture for Deterministic Networking (DetNet), which provides a capability to carry specified unicast or multicast data flows for real-time applications with extremely low data loss rates and bounded latency within a network domain. Techniques used include 1) reserving data-plane resources for individual (or aggregated) DetNet flows in some or all of the intermediate nodes along the path of the flow, 2) providing explicit routes for DetNet flows that do not immediately change with the network topology, and 3) distributing data from DetNet flow packets over time and/or space to ensure delivery of each packet's data in spite of the loss of a path. DetNet operates at the IP layer and delivers service over lower-layer technologies such as MPLS and Time- Sensitive Networking (TSN) as defined by IEEE 802.1.
RFC8654 - Extended Message Support for BGP
The BGP specification (RFC 4271) mandates a maximum BGP message size of 4,096 octets. As BGP is extended to support new Address Family Identifiers (AFIs), Subsequent AFIs (SAFIs), and other features, there is a need to extend the maximum message size beyond 4,096 octets. This document updates the BGP specification by extending the maximum message size from 4,096 octets to 65,535 octets for all messages except for OPEN and KEEPALIVE messages.
RFC8653 - On-Demand Mobility Management
Applications differ with respect to whether they need session continuity and/or IP address reachability. The network providing the same type of service to any mobile host and any application running on the host yields inefficiencies, as described in RFC 7333. This document defines a new concept of enabling applications to influence the network's mobility services (session continuity and/or IP address reachability) on a per-socket basis, and suggests extensions to the networking stack's API to accommodate this concept.
RFC8652 - A YANG Data Model for the Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD)
This document defines a YANG data model that can be used to configure and manage Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) devices.
RFC8651 - Dynamic Link Exchange Protocol (DLEP) Control-Plane-Based Pause Extension
This document defines an extension to the Dynamic Link Exchange Protocol (DLEP) that enables a modem to use DLEP messages to pause and resume data traffic coming from its peer router.
RFC8650 - Dynamic Subscription to YANG Events and Datastores over RESTCONF
This document provides a RESTCONF binding to the dynamic subscription capability of both subscribed notifications and YANG-Push.
RFC8649 - Hash Of Root Key Certificate Extension
This document specifies the Hash Of Root Key certificate extension. This certificate extension is carried in the self-signed certificate for a trust anchor, which is often called a Root Certification Authority (CA) certificate. This certificate extension unambiguously identifies the next public key that will be used at some point in the future as the next Root CA certificate, eventually replacing the current one.
RFC8645 - Re-keying Mechanisms for Symmetric Keys
A certain maximum amount of data can be safely encrypted when encryption is performed under a single key. This amount is called the "key lifetime". This specification describes a variety of methods for increasing the lifetime of symmetric keys. It provides two types of re-keying mechanisms based on hash functions and block ciphers that can be used with modes of operations such as CTR, GCM, CBC, CFB, and OMAC.
RFC8643 - An Opportunistic Approach for Secure Real-time Transport Protocol (OSRTP)
Opportunistic Secure Real-time Transport Protocol (OSRTP) is an implementation of the Opportunistic Security mechanism, as defined in RFC 7435, applied to the Real-time Transport Protocol (RTP). OSRTP allows encrypted media to be used in environments where support for encryption is not known in advance and is not required. OSRTP does not require Session Description Protocol (SDP) extensions or features and is fully backwards compatible with existing implementations using encrypted and authenticated media and implementations that do not encrypt or authenticate media packets. OSRTP is not specific to any key management technique for Secure RTP (SRTP). OSRTP is a transitional approach useful for migrating existing deployments of real-time communications to a fully encrypted and authenticated state.
RFC8642 - Policy Behavior for Well-Known BGP Communities
Well-known BGP communities are manipulated differently across various current implementations, resulting in difficulties for operators. Network operators should deploy consistent community handling across their networks while taking the inconsistent behaviors from the various BGP implementations into consideration. This document recommends specific actions to limit future inconsistency: namely, BGP implementors must not create further inconsistencies from this point forward. These behavioral changes, though subtle, actually update RFC 1997.
RFC8641 - Subscription to YANG Notifications for Datastore Updates
This document describes a mechanism that allows subscriber applications to request a continuous and customized stream of updates from a YANG datastore. Providing such visibility into updates enables new capabilities based on the remote mirroring and monitoring of configuration and operational state.
RFC8640 - Dynamic Subscription to YANG Events and Datastores over NETCONF
This document provides a Network Configuration Protocol (NETCONF) binding to the dynamic subscription capability of both subscribed notifications and YANG-Push.
RFC8639 - Subscription to YANG Notifications
This document defines a YANG data model and associated mechanisms enabling subscriber-specific subscriptions to a publisher's event streams. Applying these elements allows a subscriber to request and receive a continuous, customized feed of publisher-generated information.
RFC8638 - IPv4 Multicast over an IPv6 Multicast in Softwire Mesh Networks
During the transition to IPv6, there are scenarios where a backbone network internally running one IP address family (referred to as the internal IP or I-IP family) connects client networks running another IP address family (referred to as the external IP or E-IP family). In such cases, the I-IP backbone needs to offer both unicast and multicast transit services to the client E-IP networks.
RFC8637 - Applicability of the Path Computation Element (PCE) to the Abstraction and Control of TE Networks (ACTN)
Abstraction and Control of TE Networks (ACTN) refers to the set of virtual network (VN) operations needed to orchestrate, control, and manage large-scale multidomain TE networks so as to facilitate network programmability, automation, efficient resource sharing, and end-to-end virtual service-aware connectivity and network function virtualization services.
RFC8636 - Public Key Cryptography for Initial Authentication in Kerberos (PKINIT) Algorithm Agility
This document updates the Public Key Cryptography for Initial Authentication in Kerberos (PKINIT) standard (RFC 4556) to remove protocol structures tied to specific cryptographic algorithms. The PKINIT key derivation function is made negotiable, and the digest algorithms for signing the pre-authentication data and the client's X.509 certificates are made discoverable.
RFC8635 - Router Keying for BGPsec
BGPsec-speaking routers are provisioned with private keys in order to sign BGPsec announcements. The corresponding public keys are published in the Global Resource Public Key Infrastructure (RPKI), enabling verification of BGPsec messages. This document describes two methods of generating the public-private key pairs: router-driven and operator-driven.