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diff --git a/doc/rfc/rfc8676.txt b/doc/rfc/rfc8676.txt new file mode 100644 index 0000000..685c96b --- /dev/null +++ b/doc/rfc/rfc8676.txt @@ -0,0 +1,2454 @@ + + + + +Internet Engineering Task Force (IETF) I. Farrer, Ed. +Request for Comments: 8676 Deutsche Telekom AG +Category: Standards Track M. Boucadair, Ed. +ISSN: 2070-1721 Orange + November 2019 + + + YANG Modules for IPv4-in-IPv6 Address plus Port (A+P) Softwires + +Abstract + + 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. + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 7841. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + https://www.rfc-editor.org/info/rfc8676. + +Copyright Notice + + Copyright (c) 2019 IETF Trust and the persons identified as the + document authors. All rights reserved. + + This document is subject to BCP 78 and the IETF Trust's Legal + Provisions Relating to IETF Documents + (https://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + +Table of Contents + + 1. Introduction + 2. Terminology + 3. Overview of the Modules + 3.1. Overall Structure + 3.2. Configuration for Additional Components + 4. Softwire CE YANG Tree Diagram + 4.1. CE Tree Diagram + 4.2. Softwire CE Tree Diagram Description + 5. Softwire BR YANG Tree Diagram + 5.1. BR Tree Diagram + 5.2. Softwire BR Tree Diagram Description + 6. Softwire CE YANG Module + 7. BR Softwire YANG Module + 8. Common Softwire Element Groups YANG Module + 9. Security Considerations + 10. IANA Considerations + 11. References + 11.1. Normative References + 11.2. Informative References + Appendix A. Configuration Examples + A.1. Configuration Example for a lw4o6 BR Binding-Table + A.2. Configuration Example for a MAP-E BR + A.3. lw4o6 CE Configuration Example + Acknowledgements + Contributors + Authors' Addresses + +1. Introduction + + The IETF Softwire Working Group has developed several IPv4-in-IPv6 + softwire mechanisms to address various deployment contexts and + constraints. As a companion to the architectural specification + documents, this document focuses on the provisioning of Address plus + Port (A+P) softwire functional elements: Border Routers (BRs) and + Customer Edge (CE) (called "Customer Premises Equipment (CPE)" in + [RFC7596]). The softwire mechanisms covered in this document are + Lightweight 4over6 (lw4o6) [RFC7596], Mapping of Address and Port + with Encapsulation (MAP-E) [RFC7597], and Mapping of Address and Port + using Translation (MAP-T) [RFC7599]. + + This document focuses on A+P mechanisms [RFC6346]; the reader can + refer to [RFC8513] for a YANG module for Dual-Stack Lite (DS-Lite) + [RFC6333]. + + This document defines YANG modules [RFC7950] that can be used to + configure and manage A+P softwire elements using the NETCONF + [RFC6241] or RESTCONF [RFC8040] protocols for: + + * Configuration + + * Operational State + + * Notifications + +2. Terminology + + The reader should be familiar with the concepts and terms defined in + [RFC7596], [RFC7597], [RFC7599], and the YANG data modeling language + defined in [RFC7950]. + + The YANG modules in this document adopt the Network Management + Datastore Architecture (NMDA) [RFC8342]. The meanings of the symbols + used in tree diagrams are defined in [RFC8340]. + + The document uses the abbreviation 'BR' as a general term for + softwire tunnel concentrators, including both MAP Border Routers + [RFC7597] and Lightweight 4over6 lwAFTRs [RFC7596]. + + For brevity, "algorithm" is used to refer to the "mapping algorithm" + defined in [RFC7597]. + + A network element may support one or multiple instances of a softwire + mechanism; each of these instances (i.e., binding instances, MAP-E + instances, or MAP-T instances) may have its own configuration and + parameters. The term 'algo-instance' is used to denote both MAP-E + and MAP-T instances. + +3. Overview of the Modules + +3.1. Overall Structure + + The document defines the following two YANG modules for the + configuration and monitoring of softwire functional elements: + + ietf-softwire-ce + Provides configuration and monitoring for softwire CE element. + This module is defined as augments to the interface YANG module + [RFC8343]. + + ietf-softwire-br + Provides configuration and monitoring for softwire BR element. + + In addition, the following module is defined: + + ietf-softwire-common + Contains groups of common functions that are imported into the + CE and BR modules. + + This approach has been taken so that the various modules can be + easily extended to support additional softwire mechanisms, if + required. + + Within the BR and CE modules, the YANG "feature" statement is used to + distinguish which of the different softwire mechanism(s) is relevant + for a specific element's configuration. For each module, a choice + statement 'ce-type' is included for either 'binding' or 'algorithm'. + 'Binding' is used for configuring Lightweight 4over6, whereas + 'algorithm' is used for configuring MAP-T or MAP-E. + + In the 'algo-instances' container, a choice statement 'data-plane' is + included to specify MAP-E (encapsulation) or MAP-T (translation). + Table 1 shows how these choices are used to indicate the desired + softwire mechanism: + + +--------------------+-----------+---------------+ + | S46 Mechanism | ce-type? | data-plane? | + +====================+===========+===============+ + | Lightweight 4over6 | binding | n/a | + +--------------------+-----------+---------------+ + | MAP-E | algorithm | encapsulation | + +--------------------+-----------+---------------+ + | MAP-T | algorithm | translation | + +--------------------+-----------+---------------+ + + Table 1: Softwire Mechanism Choice + Statement Enumeration + + NETCONF notifications are also included. + + | Earlier draft versions of this specification combined the + | softwire mechanisms by their associated technologies rather + | than their function in the architecture. As the document was + | revised, it became apparent that dividing the modules by their + | role in the architecture (CE or BR) was a better approach as + | this follows the intended function and existing implementation + | approaches more closely. + +3.2. Configuration for Additional Components + + The softwire modules only aim to provide configuration relevant for + softwires. In order to fully provision a CE element, the following + may also be necessary: + + * IPv6 forwarding and routing configuration, to enable the CE to + obtain one or more IPv6 prefixes for softwire usage. A YANG + module for routing management is described in [RFC8349]. + + * IPv4 routing configuration, to add one or more IPv4 destination + prefix(es) reachable via the configured softwire. A YANG module + for routing management is described in [RFC8349]. + + * Stateful NAT44/NAPT management, to optionally specify a port set + (Port Set Identifier (PSID)) along with its length. A YANG module + for NAT management is described in [RFC8512]. + + * Stateless NAT46 management, which is required by softwire- + translation-based mechanisms (i.e., the assignment of a Network- + Specific Prefix to use for IPv4/IPv6 translation). A YANG module + for NAT management is described in [RFC8512]. + + As YANG modules for the above functions are already defined in other + documents, their functionality is not duplicated here and they should + be referred to, as needed. Appendix A.3 provides XML examples of how + these modules can be used together. + + The CE must already have minimal IPv6 configuration in place so it is + reachable by the NETCONF client to obtain softwire configuration. If + additional IPv6-specific configuration is necessary, the YANG modules + defined in [RFC8344] and [RFC8349] may be used. + +4. Softwire CE YANG Tree Diagram + +4.1. CE Tree Diagram + + The CE module provides configuration and monitoring for all of the + softwire mechanisms covered in this document (i.e., Lightweight + 4over6, MAP-E, and MAP-T). + + This module augments "ietf-interfaces", defined in [RFC8343] with an + entry for the softwire. This entry can be referenced to configure + IPv4 forwarding features for the element. This entry is added only + if tunnel type (Section 10) is set to 'aplusp'. + + Figure 1 shows the tree structure of the softwire CE YANG module: + + + module: ietf-softwire-ce + augment /if:interfaces/if:interface: + +--rw softwire-payload-mtu? uint16 + +--rw softwire-path-mru? uint16 + +--rw (ce-type)? + +--:(binding) {binding-mode}? + | +--rw binding-ipv6info? union + | +--rw br-ipv6-addr inet:ipv6-address + +--:(algo) {map-e or map-t}? + +--rw algo-instances + +--rw algo-instance* [name] + +--rw name string + +--rw enable? boolean + +--rw algo-versioning + | +--rw version? uint64 + | +--rw date? yang:date-and-time + +--rw (data-plane)? + | +--:(encapsulation) {map-e}? + | | +--rw br-ipv6-addr inet:ipv6-address + | +--:(translation) {map-t}? + | +--rw dmr-ipv6-prefix? inet:ipv6-prefix + +--rw ea-len uint8 + +--rw rule-ipv6-prefix inet:ipv6-prefix + +--rw rule-ipv4-prefix inet:ipv4-prefix + +--rw forwarding boolean + augment /if:interfaces/if:interface/if:statistics: + +--ro sent-ipv4-packets? + | yang:zero-based-counter64 + +--ro sent-ipv4-bytes? + | yang:zero-based-counter64 + +--ro sent-ipv6-packets? + | yang:zero-based-counter64 + +--ro sent-ipv6-bytes? + | yang:zero-based-counter64 + +--ro rcvd-ipv4-packets? + | yang:zero-based-counter64 + +--ro rcvd-ipv4-bytes? + | yang:zero-based-counter64 + +--ro rcvd-ipv6-packets? + | yang:zero-based-counter64 + +--ro rcvd-ipv6-bytes? + | yang:zero-based-counter64 + +--ro dropped-ipv4-packets? + | yang:zero-based-counter64 + +--ro dropped-ipv4-bytes? + | yang:zero-based-counter64 + +--ro dropped-ipv6-packets? + | yang:zero-based-counter64 + +--ro dropped-ipv6-bytes? + | yang:zero-based-counter64 + +--ro dropped-ipv4-fragments? + | yang:zero-based-counter64 + +--ro dropped-ipv4-fragment-bytes? + | yang:zero-based-counter64 + +--ro ipv6-fragments-reassembled? + | yang:zero-based-counter64 + +--ro ipv6-fragments-bytes-reassembled? + | yang:zero-based-counter64 + +--ro out-icmpv4-error-packets? + | yang:zero-based-counter64 + +--ro out-icmpv4-error-bytes? + | yang:zero-based-counter64 + +--ro out-icmpv6-error-packets? + | yang:zero-based-counter64 + +--ro out-icmpv6-error-bytes? + yang:zero-based-counter64 + + notifications: + +---n softwire-ce-event {binding-mode}? + +--ro ce-binding-ipv6-addr-change inet:ipv6-address + + Figure 1: Softwire CE YANG Tree Diagram + +4.2. Softwire CE Tree Diagram Description + + Additional information related to the operation of a CE element is + provided below: + + softwire-payload-mtu: + optionally used to set the IPv4 Maximum Transmission Unit (MTU) + for the softwire. Needed if the softwire implementation is + unable to correctly calculate the correct IPv4 MTU size + automatically. + + softwire-path-mru: + optionally used to set the maximum IPv6 softwire packet size + that can be received, including the encapsulation/translation + overhead. Needed if the softwire implementation is unable to + correctly calculate the correct IPv4 payload Maximum Receive + Unit (MRU) size automatically (see Section 3.2 of [RFC4213]). + + ce-type: + provides a choice statement allowing the binding or algorithmic + softwire mechanisms to be selected. + + Further details relevant to binding softwire elements are as follows: + + binding-ipv6info: + used to set the IPv6 binding prefix type to identify which IPv6 + address to use as the tunnel source. It can be 'ipv6-prefix' + or 'ipv6-address'. + + br-ipv6-addr: + sets the IPv6 address of the remote BR. + + Additional details relevant to some of the important algorithmic + elements are provided below: + + algo-versioning: + optionally used to associate a version number and/or timestamp + to the algorithm. This can be used for logging/data retention + purposes [RFC7422]. The version number is selected to uniquely + identify the algorithm configuration and a new value written + whenever a change is made to the algorithm or a new algo- + instance is created. + + forwarding: + specifies whether the rule can be used as a Forwarding Mapping + Rule (FMR). If not set, this rule is a Basic Mapping Rule + (BMR) only and must not be used for forwarding. Refer to + Section 4.1 of [RFC7598]. + + ea-len: + used to set the length of the Embedded-Address (EA), which is + defined in the mapping rule for a MAP domain. + + data-plane: + provides a choice statement for either encapsulation (MAP-E) or + translation (MAP-T). + + br-ipv6-addr: + defines the IPv6 address of the BR. This information is valid + for MAP-E. + + dmr-ipv6-prefix: + defines the Default Mapping Rule (DMR) IPv6 prefix of the BR. + This information is valid for MAP-T. + + Additional information on the notification node is listed below: + + ce-binding-ipv6-addr-change: + if the CE's binding IPv6 address changes for any reason, the + NETCONF client will be notified. + +5. Softwire BR YANG Tree Diagram + +5.1. BR Tree Diagram + + The BR YANG module provides configuration and monitoring for all of + the softwire mechanisms covered in this document (i.e., Lightweight + 4over6, MAP-E, and MAP-T). + + Figure 2 provides the tree structure of this module: + + module: ietf-softwire-br + +--rw br-instances + +--rw (br-type)? + +--:(binding) {binding-mode}? + | +--rw binding + | +--rw bind-instance* [name] + | +--rw name string + | +--rw binding-table-versioning + | | +--rw version? uint64 + | | +--rw date? yang:date-and-time + | +--rw softwire-num-max uint32 + | +--rw softwire-payload-mtu uint16 + | +--rw softwire-path-mru uint16 + | +--rw enable-hairpinning? boolean + | +--rw binding-table + | | +--rw binding-entry* [binding-ipv6info] + | | +--rw binding-ipv6info union + | | +--rw binding-ipv4-addr? + | | | inet:ipv4-address + | | +--rw port-set + | | | +--rw psid-offset? uint8 + | | | +--rw psid-len uint8 + | | | +--rw psid uint16 + | | +--rw br-ipv6-addr? + | | inet:ipv6-address + | +--rw icmp-policy + | | +--rw icmpv4-errors + | | | +--rw allow-incoming-icmpv4? boolean + | | | +--rw icmpv4-rate? uint32 + | | | +--rw generate-icmpv4-errors? boolean + | | +--rw icmpv6-errors + | | +--rw generate-icmpv6-errors? boolean + | | +--rw icmpv6-rate? uint32 + | +--ro traffic-stat + | +--ro discontinuity-time yang:date-and-time + | +--ro sent-ipv4-packets? + | | yang:zero-based-counter64 + | +--ro sent-ipv4-bytes? + | | yang:zero-based-counter64 + | +--ro sent-ipv6-packets? + | | yang:zero-based-counter64 + | +--ro sent-ipv6-bytes? + | | yang:zero-based-counter64 + | +--ro rcvd-ipv4-packets? + | | yang:zero-based-counter64 + | +--ro rcvd-ipv4-bytes? + | | yang:zero-based-counter64 + | +--ro rcvd-ipv6-packets? + | | yang:zero-based-counter64 + | +--ro rcvd-ipv6-bytes? + | | yang:zero-based-counter64 + | +--ro dropped-ipv4-packets? + | | yang:zero-based-counter64 + | +--ro dropped-ipv4-bytes? + | | yang:zero-based-counter64 + | +--ro dropped-ipv6-packets? + | | yang:zero-based-counter64 + | +--ro dropped-ipv6-bytes? + | | yang:zero-based-counter64 + | +--ro dropped-ipv4-fragments? + | | yang:zero-based-counter64 + | +--ro dropped-ipv4-fragment-bytes? + | | yang:zero-based-counter64 + | +--ro ipv6-fragments-reassembled? + | | yang:zero-based-counter64 + | +--ro ipv6-fragments-bytes-reassembled? + | | yang:zero-based-counter64 + | +--ro out-icmpv4-error-packets? + | | yang:zero-based-counter64 + | +--ro out-icmpv4-error-bytes? + | | yang:zero-based-counter64 + | +--ro out-icmpv6-error-packets? + | | yang:zero-based-counter64 + | +--ro out-icmpv6-error-bytes? + | | yang:zero-based-counter64 + | +--ro dropped-icmpv4-packets? + | | yang:zero-based-counter64 + | +--ro dropped-icmpv4-bytes? + | | yang:zero-based-counter64 + | +--ro hairpin-ipv4-packets? + | | yang:zero-based-counter64 + | +--ro hairpin-ipv4-bytes? + | | yang:zero-based-counter64 + | +--ro active-softwire-num? + | uint32 + +--:(algo) {map-e or map-t}? + +--rw algorithm + +--rw algo-instance* [name] + +--rw name string + +--rw enable? boolean + +--rw algo-versioning + | +--rw version? uint64 + | +--rw date? yang:date-and-time + +--rw (data-plane)? + | +--:(encapsulation) {map-e}? + | | +--rw br-ipv6-addr inet:ipv6-address + | +--:(translation) {map-t}? + | +--rw dmr-ipv6-prefix? inet:ipv6-prefix + +--rw ea-len uint8 + +--rw rule-ipv6-prefix inet:ipv6-prefix + +--rw rule-ipv4-prefix inet:ipv4-prefix + +--rw forwarding boolean + +--rw port-set + | +--rw psid-offset? uint8 + | +--rw psid-len uint8 + | +--rw psid uint16 + +--ro traffic-stat + +--ro discontinuity-time yang:date-and-time + +--ro sent-ipv4-packets? + | yang:zero-based-counter64 + +--ro sent-ipv4-bytes? + | yang:zero-based-counter64 + +--ro sent-ipv6-packets? + | yang:zero-based-counter64 + +--ro sent-ipv6-bytes? + | yang:zero-based-counter64 + +--ro rcvd-ipv4-packets? + | yang:zero-based-counter64 + +--ro rcvd-ipv4-bytes? + | yang:zero-based-counter64 + +--ro rcvd-ipv6-packets? + | yang:zero-based-counter64 + +--ro rcvd-ipv6-bytes? + | yang:zero-based-counter64 + +--ro dropped-ipv4-packets? + | yang:zero-based-counter64 + +--ro dropped-ipv4-bytes? + | yang:zero-based-counter64 + +--ro dropped-ipv6-packets? + | yang:zero-based-counter64 + +--ro dropped-ipv6-bytes? + | yang:zero-based-counter64 + +--ro dropped-ipv4-fragments? + | yang:zero-based-counter64 + +--ro dropped-ipv4-fragment-bytes? + | yang:zero-based-counter64 + +--ro ipv6-fragments-reassembled? + | yang:zero-based-counter64 + +--ro ipv6-fragments-bytes-reassembled? + | yang:zero-based-counter64 + +--ro out-icmpv4-error-packets? + | yang:zero-based-counter64 + +--ro out-icmpv4-error-bytes? + | yang:zero-based-counter64 + +--ro out-icmpv6-error-packets? + | yang:zero-based-counter64 + +--ro out-icmpv6-error-bytes? + yang:zero-based-counter64 + + notifications: + +---n softwire-binding-instance-event {binding-mode}? + | +--ro bind-name? + | | -> /br-instances/binding/bind-instance/name + | +--ro invalid-entry* leafref + | +--ro added-entry* inet:ipv6-address + | +--ro modified-entry* leafref + +---n softwire-algorithm-instance-event {map-e, map-t}? + +--ro algo-name + | -> /br-instances/algorithm/algo-instance/name + +--ro invalid-entry-id* + | -> /br-instances/algorithm/algo-instance/name + +--ro added-entry* + | -> /br-instances/algorithm/algo-instance/name + +--ro modified-entry* + -> /br-instances/algorithm/algo-instance/name + + Figure 2: Softwire BR YANG Tree + +5.2. Softwire BR Tree Diagram Description + + The descriptions for leaves that are common with the CE module are + provided in Section 4.2. Descriptions for additional elements are + provided below: + + binding-table-versioning: + optionally used to associate a version number and/or timestamp + to the binding table. This can be used for logging or data + retention purposes [RFC7422]. The version number is selected + to uniquely identify the binding table configuration and a new + timestamp value written whenever a change is made to the + contents of the binding table or a new binding table list is + created. + + binding-entry: + used to define the binding relationship between 3-tuples + {lwB4's IPv6 address/prefix, the allocated IPv4 address, + restricted port-set}. For detailed information, please refer + to [RFC7596]. + + softwire-num-max: + used to set the maximum number of softwire binding rules that + can be created on the lw4o6 element simultaneously. This + parameter must not be set to zero because this is equivalent to + disabling the BR instance. + + active-softwire-num: + holds the number of softwires currently provisioned on the BR + element. + + Additional information on some of the important notification nodes is + listed below: + + invalid-entry, added-entry, modified-entry: + used to notify the NETCONF client that a specific binding entry + or MAP rule has expired, been invalidated, added, or modified. + +6. Softwire CE YANG Module + + This module imports the modules defined in [RFC6991], [RFC8343], and + [RFC7224]. It also imports the 'ietf-softwire-common' and 'iana- + tunnel-type' modules [RFC8675]. + + <CODE BEGINS> file "ietf-softwire-ce@2019-11-16.yang" + module ietf-softwire-ce { + yang-version 1.1; + namespace "urn:ietf:params:xml:ns:yang:ietf-softwire-ce"; + prefix softwire-ce; + + import ietf-inet-types { + prefix inet; + reference + "RFC 6991: Common YANG Data Types, Section 4"; + } + import ietf-interfaces { + prefix if; + reference + "RFC 8343: A YANG Data Model for Interface Management"; + } + import ietf-softwire-common { + prefix softwire-common; + reference + "RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port + Softwires"; + } + import iana-tunnel-type { + prefix iana-tunnel-type; + reference + "RFC 8675: A YANG Data Model for Tunnel Interface Types"; + } + + organization + "IETF Softwire Working Group"; + contact + "WG Web: <https://datatracker.ietf.org/wg/softwire/> + WG List: <mailto:softwire@ietf.org> + + Author: Qi Sun + <mailto:sunqi.ietf@gmail.com> + + Author: Linhui Sun + <mailto:lh.sunlinh@gmail.com> + + Author: Yong Cui + <mailto:yong@csnet1.cs.tsinghua.edu.cn> + + Editor: Ian Farrer + <mailto:ian.farrer@telekom.de> + + Author: Sladjana Zoric + <mailto:sladjana.zoric@telekom.de> + + Editor: Mohamed Boucadair + <mailto:mohamed.boucadair@orange.com> + + Author: Rajiv Asati + <mailto:rajiva@cisco.com>"; + description + "This document defines a YANG module for the configuration and + management of A+P Softwire Customer Premises Equipment (CEs). + It covers Lightweight 4over6, MAP-E, and MAP-T mechanisms. + + Copyright (c) 2019 IETF Trust and the persons identified as + authors of the code. All rights reserved. + + Redistribution and use in source and binary forms, with or + without modification, is permitted pursuant to, and subject + to the license terms contained in, the Simplified BSD License + set forth in Section 4.c of the IETF Trust's Legal Provisions + Relating to IETF Documents + (http://trustee.ietf.org/license-info). + + This version of this YANG module is part of RFC 8676; see + the RFC itself for full legal notices."; + + revision 2019-11-16 { + description + "Initial revision."; + reference + "RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port + (A+P) Softwires"; + } + + /* + * Features + */ + + feature binding-mode { + description + "Binding is used for configuring the Lightweight 4over6 + mechanism. + + Binding-based softwire mechanisms are IPv4-over-IPv6 tunneling + transition mechanisms specifically intended for complete + independence between the IPv6 subnet prefix (and IPv6 address) + and IPv4 address, with or without IPv4 address sharing. + + This is accomplished by maintaining state for each softwire + (per-subscriber state) in the central Border Relay (BR) and + using a hub-and-spoke forwarding architecture. In order to + delegate the NAPT function and achieve IPv4 address sharing, + port-restricted IPv4 addresses needs to be allocated to CEs. + + This feature indicates that the network element can function + as one or more binding-based softwire instances."; + reference + "RFC 7596: Lightweight 4over6: An Extension to the Dual-Stack + Lite Architecture + RFC 7597: Mapping of Address and Port with Encapsulation + (MAP-E) + RFC 7599: Mapping of Address and Port using Translation + (MAP-T)"; + } + + feature map-e { + description + "MAP-E is an IPv6 transition mechanism for transporting IPv4 + packets across an IPv6 network using IP encapsulation. MAP-E + allows for a reduction of the amount of centralized state + using rules to express IPv4/IPv6 address mappings. This + introduces an algorithmic relationship between the IPv6 + subnet and IPv4 address. + + This feature indicates that the network element can function + as one or more MAP-E softwire instances."; + reference + "RFC 7597: Mapping of Address and Port with + Encapsulation (MAP-E)"; + } + + feature map-t { + description + "MAP-T is an IPv6 transition mechanism for transporting IPv4 + packets across an IPv6 network using IP translation. It + leverages a double stateless NAT64-based solution as well as + the stateless algorithmic address and transport layer port + mapping algorithm defined for MAP-E. + + This feature indicates that the network element can function + as one or more MAP-T softwire instances."; + reference + "RFC 7599: Mapping of Address and Port using Translation + (MAP-T)"; + } + + // Binding Entry + + grouping binding-entry { + description + "The binding BR (Border Relay) maintains an address + binding table that contains the binding between the CE's + IPv6 address, the allocated IPv4 address, and the + restricted port-set."; + leaf binding-ipv6info { + type union { + type inet:ipv6-address; + type inet:ipv6-prefix; + } + description + "The IPv6 information for a binding entry. + + When the IPv6 prefix type is used, + the IPv6 source address of the CE is constructed + according to the description in RFC 7596. + + If the IPv6 address type is used, the CE can use + any valid /128 address from a prefix assigned to + the CE."; + reference + "RFC 7596: Lightweight 4over6: An Extension + to the Dual-Stack Lite Architecture, Section 5.1"; + } + leaf br-ipv6-addr { + type inet:ipv6-address; + mandatory true; + description + "The IPv6 address of the binding BR."; + } + } + + // configuration and stateful parameters for softwire CE interface + + augment "/if:interfaces/if:interface" { + when "derived-from(if:type, 'iana-tunnel-type:aplusp')"; + description + "Softwire CE interface configuration"; + leaf softwire-payload-mtu { + type uint16; + units "bytes"; + description + "The payload IPv4 MTU for the softwire tunnel."; + } + leaf softwire-path-mru { + type uint16; + units "bytes"; + description + "The path MRU for the softwire (payload + encapsulation + overhead)."; + reference + "RFC 4213: Basic Transition Mechanisms for IPv6 Hosts and + Routers"; + } + choice ce-type { + description + "Sets the softwire CE mechanism"; + case binding { + if-feature "binding-mode"; + description + "CE binding configuration"; + uses binding-entry; + } + case algo { + if-feature "map-e or map-t"; + description + "CE algorithm configuration"; + container algo-instances { + description + "Collection of MAP-E/MAP-T parameters"; + list algo-instance { + key "name"; + description + "MAP forwarding rule instance for + MAP-E/MAP-T"; + leaf name { + type string; + mandatory true; + description + "The name is used to uniquely identify an algorithm + instance. + + This name can be automatically assigned + or explicitly configured."; + } + uses softwire-common:algorithm-instance; + } + } + } + } + } + augment "/if:interfaces/if:interface/if:statistics" { + when "derived-from(../if:type, 'iana-tunnel-type:aplusp')"; + description + "Softwire CE interface statistics."; + uses softwire-common:traffic-stat; + } + + /* + * Notifications + */ + + notification softwire-ce-event { + if-feature "binding-mode"; + description + "CE notification"; + leaf ce-binding-ipv6-addr-change { + type inet:ipv6-address; + mandatory true; + description + "This notification is generated whenever the CE's binding + IPv6 address changes for any reason."; + } + } + } + <CODE ENDS> + +7. BR Softwire YANG Module + + This module imports typedefs from [RFC6991]. It also imports the + 'ietf-softwire-common' module. + + <CODE BEGINS> file "ietf-softwire-br@2019-11-16.yang" + module ietf-softwire-br { + yang-version 1.1; + namespace "urn:ietf:params:xml:ns:yang:ietf-softwire-br"; + prefix softwire-br; + + import ietf-inet-types { + prefix inet; + reference + "RFC 6991: Common YANG Data Types, Section 4"; + } + import ietf-yang-types { + prefix yang; + reference + "RFC 6991: Common YANG Data Types, Section 3"; + } + import ietf-softwire-common { + prefix softwire-common; + reference + "RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port + (A+P) Softwires"; + } + + organization + "IETF Softwire Working Group"; + contact + "WG Web: <https://datatracker.ietf.org/wg/softwire/> + WG List: <mailto:softwire@ietf.org> + + Author: Qi Sun + <mailto:sunqi.ietf@gmail.com> + + Author: Linhui Sun + <mailto:lh.sunlinh@gmail.com> + + Author: Yong Cui + <mailto:yong@csnet1.cs.tsinghua.edu.cn> + + Editor: Ian Farrer + <mailto:ian.farrer@telekom.de> + + Author: Sladjana Zoric + <mailto:sladjana.zoric@telekom.de> + + Editor: Mohamed Boucadair + <mailto:mohamed.boucadair@orange.com> + + Author: Rajiv Asati + <mailto:rajiva@cisco.com>"; + + description + "This document defines a YANG module for the configuration and + management of A+P Softwire Border Routers. It covers + Lightweight 4over6, MAP-E, and MAP-T mechanisms. + + Copyright (c) 2019 IETF Trust and the persons identified as + authors of the code. All rights reserved. + + Redistribution and use in source and binary forms, with or + without modification, is permitted pursuant to, and subject + to the license terms contained in, the Simplified BSD License + set forth in Section 4.c of the IETF Trust's Legal Provisions + Relating to IETF Documents + (http://trustee.ietf.org/license-info). + + This version of this YANG module is part of RFC 8676; see + the RFC itself for full legal notices."; + + revision 2019-11-16 { + description + "Initial revision."; + reference + "RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port + (A+P) Softwires"; + } + + /* + * Groupings + */ + + grouping port-set { + description + "Describes a set of Layer 4 port numbers. + + This may be a simple port range, or use the Port Set + Identifier (PSID) algorithm to represent a range of transport + layer ports that will be used by a NAPT."; + leaf psid-offset { + type uint8 { + range "0..16"; + } + description + "The number of offset bits. In Lightweight 4over6, + the default value is 0 for assigning one contiguous + port range. In MAP-E/T, the default value is 6, + which means the system ports (0-1023) are excluded by + default and the assigned port ranges are distributed across + the entire port space, depending on either psid-len or the + number of contiguous ports."; + } + leaf psid-len { + type uint8 { + range "0..15"; + } + mandatory true; + description + "The length of PSID, representing the sharing + ratio for an IPv4 address. This, along with ea-len, can + be used to calculate the number of contiguous ports per + port range"; + } + leaf psid { + type uint16; + mandatory true; + description + "Port Set Identifier (PSID) value, which + identifies a set of ports algorithmically."; + } + } + + grouping binding-entry { + description + "The binding BR maintains an address binding table that + contains the binding between the CE's IPv6 address, + the allocated IPv4 address and restricted port-set."; + leaf binding-ipv6info { + type union { + type inet:ipv6-address; + type inet:ipv6-prefix; + } + description + "The IPv6 information for a CE binding entry. + When the IPv6 prefix type is used, + the IPv6 source address of the CE is constructed + according to the description in RFC 7596; + if the IPv6 address type is used, the CE can use + any valid /128 address from a prefix assigned to + the CE."; + reference + "RFC 7596: Lightweight 4over6: An Extension to the Dual-Stack + Lite Architecture"; + } + leaf binding-ipv4-addr { + type inet:ipv4-address; + description + "The IPv4 address assigned to the binding CE, + which is used as the IPv4 external address + for binding CE local NAPT44."; + } + container port-set { + description + "For Lightweight 4over6, the default value + for offset should be 0, to configure one contiguous + port range."; + uses port-set { + refine "psid-offset" { + default "0"; + } + } + } + leaf br-ipv6-addr { + type inet:ipv6-address; + description + "The IPv6 address for binding BR."; + } + } + + /* + * Features + */ + + feature binding-mode { + description + "Binding is used for configuring the Lightweight 4over6 + mechanism. + + Binding-based softwire mechanisms are IPv4-over-IPv6 tunneling + transition mechanisms specifically intended for complete + independence between the IPv6 subnet prefix (and IPv6 address) + and IPv4 address, with or without IPv4 address sharing. + + This is accomplished by maintaining state for each softwire + (per-subscriber state) in the central Border Relay (BR) and + using a hub-and-spoke forwarding architecture. In order to + delegate the NAPT function and achieve IPv4 address sharing, + port-restricted IPv4 addresses needs to be allocated to CEs. + + This feature indicates that the network element can function + as one or more binding-based softwire instances."; + reference + "RFC 7596: Lightweight 4over6: An Extension to the Dual-Stack + Lite Architecture + RFC 7597: Mapping of Address and Port with Encapsulation + (MAP-E) + RFC 7599: Mapping of Address and Port using Translation + (MAP-T)"; + } + + feature map-e { + description + "MAP-E is an IPv6 transition mechanism for transporting IPv4 + packets across an IPv6 network using IP encapsulation. MAP-E + allows for a reduction of the amount of centralized state + using rules to express IPv4/IPv6 address mappings. This + introduces an algorithmic relationship between the IPv6 subnet + and IPv4 address. + + This feature indicates that the network element can function + as one or more MAP-E softwire instances."; + reference + "RFC 7597: Mapping of Address and Port with Encapsulation + (MAP-E)"; + } + + feature map-t { + description + "MAP-T is an IPv6 transition mechanism for transporting IPv4 + packets across an IPv6 network using IP translation. It + leverages a double stateless NAT64-based solution as well + as the stateless algorithmic address and transport layer + port mapping algorithm defined for MAP-E. + + This feature indicates that the network element can function + as one or more MAP-T softwire instances."; + reference + "RFC 7599: Mapping of Address and Port using Translation + (MAP-T)"; + } + + container br-instances { + description + "BR instances enabled in a network element."; + choice br-type { + description + "Select binding or algorithmic BR functionality."; + case binding { + if-feature "binding-mode"; + container binding { + description + "binding mechanism (binding table) configuration."; + list bind-instance { + key "name"; + description + "A set of binding instances to be configured."; + leaf name { + type string; + mandatory true; + description + "The name for the binding BR. It is used to uniquely + distinguish a binding instance by its name."; + } + container binding-table-versioning { + description + "binding table's version"; + leaf version { + type uint64; + description + "Version number for this binding table."; + } + leaf date { + type yang:date-and-time; + description + "Timestamp when the binding table was activated. + + A binding instance may be provided with binding + entries that may change in time (e.g., increase + the size of the port set). When a party who is + the victim of abuse presents an external IP + address/port, the version of the binding table + is important because, depending on the version, + a distinct customer may be identified. + + The timestamp is used as a key to find the + appropriate binding table that was put into effect + when an abuse occurred."; + reference + "RFC 7422: Deterministic Address Mapping to Reduce + Logging in Carrier-Grade NAT Deployments"; + } + } + leaf softwire-num-max { + type uint32 { + range "1..max"; + } + mandatory true; + description + "The maximum number of softwires that can be created + on the binding BR."; + } + leaf softwire-payload-mtu { + type uint16; + units "bytes"; + mandatory true; + description + "The payload IPv4 MTU for binding softwire."; + } + leaf softwire-path-mru { + type uint16; + units "bytes"; + mandatory true; + description + "The path MRU for binding softwire"; + reference + "RFC 4213: Basic Transition Mechanisms for IPv6 Hosts + and Routers"; + } + leaf enable-hairpinning { + type boolean; + default "true"; + description + "Enables/disables support for locally forwarding + (hairpinning) traffic between two CEs"; + reference + "RFC 7596: Lightweight 4over6: An Extension to + the Dual-Stack Lite Architecture, Section 6.2"; + } + container binding-table { + description + "binding table"; + list binding-entry { + key "binding-ipv6info"; + description + "binding entry"; + uses binding-entry; + } + } + container icmp-policy { + description + "The binding BR can be configured to process or drop + incoming ICMP messages and to generate outgoing ICMP + error messages."; + container icmpv4-errors { + description + "ICMPv4 error processing configuration"; + leaf allow-incoming-icmpv4 { + type boolean; + default "true"; + description + "Enables the processing of incoming ICMPv4 + packets."; + reference + "RFC 7596: Lightweight 4over6: An Extension to + the Dual-Stack Lite Architecture"; + } + leaf icmpv4-rate { + type uint32; + description + "Rate limit threshold in messages per second + for processing incoming ICMPv4 errors messages"; + } + leaf generate-icmpv4-errors { + type boolean; + default "true"; + description + "Enables the generation of outgoing ICMPv4 error + messages on receipt of an inbound IPv4 packet + with no matching binding table entry."; + reference + "RFC 7596: Lightweight 4over6: + An Extension to the Dual-Stack Lite + Architecture, Section 5.2"; + } + } + container icmpv6-errors { + description + "ICMPv6 error processing configuration"; + leaf generate-icmpv6-errors { + type boolean; + default "true"; + description + "Enables the generation of ICMPv6 error messages + if no matching binding table entry is found for + a received packet."; + reference + "RFC 7596: Lightweight 4over6: + An Extension to the Dual-Stack Lite + Architecture, Section 6.2"; + } + leaf icmpv6-rate { + type uint32; + description + "Rate limit threshold in messages per second + for sending ICMPv6 errors messages"; + reference + "RFC 7596: Lightweight 4over6: An Extension + to the Dual-Stack Lite Architecture, Section 9"; + } + } + } + container traffic-stat { + config false; + description + "Traffic statistics information for the BR."; + leaf discontinuity-time { + type yang:date-and-time; + mandatory true; + description + "The time of the most recent occasion on which the + BR instance suffered a discontinuity. This must + be initialized when the BR instance is configured + or rebooted."; + } + uses softwire-common:traffic-stat; + leaf dropped-icmpv4-packets { + type yang:zero-based-counter64; + description + "ICMPv4 packets that are dropped as a result + of the ICMP policy. Typically, this can be any + incoming ICMPv4 packets if ICMPv4 processing is + disabled or incoming ICMPv4 packets that exceed + the ICMPv4 rate-limit threshold. + + Discontinuities in the value of this counter can + occur at re-initialization of the management + system and at other times as indicated by + the value of 'discontinuity-time'."; + } + leaf dropped-icmpv4-bytes { + type yang:zero-based-counter64; + description + "ICMPv4 messages, in bytes, that are dropped as + a result of the ICMP policy. Typically, it + can be any incoming ICMPv4 packets if ICMPv4 + processing is disabled or incoming ICMPv4 + packets that exceed the ICMPv4 rate-limit + threshold. + + Discontinuities in the value of this counter can + occur at re-initialization of the management + system and at other times as indicated by + the value of 'discontinuity-time'."; + } + leaf hairpin-ipv4-packets { + type yang:zero-based-counter64; + description + "IPv4 packets locally routed between two CEs + (hairpinned). + + Discontinuities in the value of this counter can + occur at re-initialization of the management + system and at other times as indicated by + the value of 'discontinuity-time'."; + } + leaf hairpin-ipv4-bytes { + type yang:zero-based-counter64; + description + "IPv4 bytes locally routed between two CEs + (hairpinned). + + Discontinuities in the value of this counter can + occur at re-initialization of the management + system and at other times as indicated by + the value of 'discontinuity-time'."; + } + leaf active-softwire-num { + type uint32; + config false; + description + "The number of currently active softwires on the + binding instance. + + Discontinuities in the value of this counter can + occur at re-initialization of the management + system and at other times as indicated by + the value of 'discontinuity-time'."; + } + } + } + } + } + case algo { + if-feature "map-e or map-t"; + container algorithm { + description + "A set of parameters used for MAP-E/MAP-T"; + list algo-instance { + key "name"; + description + "Instances of algorithm"; + leaf name { + type string; + mandatory true; + description + "The name is used to uniquely identify an algorithm + instance. + + This name can be automatically assigned + or explicitly configured."; + } + uses softwire-common:algorithm-instance; + container port-set { + description + "Indicates a set of ports."; + uses port-set; + } + container traffic-stat { + config false; + description + "Traffic statistics information for the BR."; + leaf discontinuity-time { + type yang:date-and-time; + mandatory true; + description + "The time of the most recent occasion on which the + BR instance suffered a discontinuity. This must + be reset to the current date-and-time when the BR + instance is configured or rebooted."; + } + uses softwire-common:traffic-stat; + } + } + } + } + } + } + + /* + * Notifications + */ + + notification softwire-binding-instance-event { + if-feature "binding-mode"; + description + "Notifications for the binding instance when an entry is + added, modified, or is not valid anymore."; + leaf bind-name { + type leafref { + path "/br-instances/binding/bind-instance/name"; + } + description + "The name of the binding-instance that + generated the notification."; + } + leaf-list invalid-entry { + type leafref { + path "/br-instances/binding/" + + "bind-instance[name=current()/../bind-name]/" + + "binding-table/binding-entry/binding-ipv6info"; + } + description + "Notify the client that a specific binding entry has + expired or is invalid. The binding-ipv6info identifies + an entry."; + } + leaf-list added-entry { + type inet:ipv6-address; + description + "Notify the client that a binding entry has been added. + The IPv6 address of that entry is the index. The client + gets other information from the binding BR about the entry + indexed by that ipv6 address."; + } + leaf-list modified-entry { + type leafref { + path "/br-instances/binding/" + + "bind-instance[name=current()/../bind-name]/" + + "binding-table/binding-entry/binding-ipv6info"; + } + description + "The binding table entry that has been modified."; + } + } + notification softwire-algorithm-instance-event { + if-feature "map-e or map-t"; + description + "Notifications for an algorithm instance when an entry is + added, modified, or is not valid anymore."; + leaf algo-name { + type leafref { + path "/br-instances/algorithm/algo-instance/name"; + } + mandatory true; + description + "Algorithmic instance event."; + } + leaf-list invalid-entry { + type leafref { + path "/br-instances/algorithm/algo-instance/name"; + } + description + "Invalid entry."; + } + leaf-list added-entry { + type leafref { + path "/br-instances/algorithm/algo-instance/name"; + } + description + "Added entry."; + } + leaf-list modified-entry { + type leafref { + path "/br-instances/algorithm/algo-instance/name"; + } + description + "Modified entry."; + } + } + } + <CODE ENDS> + +8. Common Softwire Element Groups YANG Module + + This module imports typedefs from [RFC6991]. + + The following YANG module contains definitions that are used by both + the softwire CE and softwire BR YANG modules. + + <CODE BEGINS> file "ietf-softwire-common@2019-11-16.yang" + module ietf-softwire-common { + yang-version 1.1; + namespace "urn:ietf:params:xml:ns:yang:ietf-softwire-common"; + prefix softwire-common; + + import ietf-inet-types { + prefix inet; + reference + "RFC 6991: Common YANG Data Types, Section 4"; + } + import ietf-yang-types { + prefix yang; + reference + "RFC 6991: Common YANG Data Types, Section 3"; + } + + organization + "IETF Softwire Working Group"; + contact + "WG Web: <https://datatracker.ietf.org/wg/softwire/> + WG List: <mailto:softwire@ietf.org> + + Author: Qi Sun + <mailto:sunqi.ietf@gmail.com> + + Author: Linhui Sun + <mailto:lh.sunlinh@gmail.com> + + Author: Yong Cui + <mailto:yong@csnet1.cs.tsinghua.edu.cn> + + Editor: Ian Farrer + <mailto:ian.farrer@telekom.de> + + Author: Sladjana Zoric + <mailto:sladjana.zoric@telekom.de> + + Editor: Mohamed Boucadair + <mailto:mohamed.boucadair@orange.com> + + Author: Rajiv Asati + <mailto:rajiva@cisco.com>"; + description + "This document defines a YANG module defining types + common to all A+P modules. + + Copyright (c) 2019 IETF Trust and the persons identified as + authors of the code. All rights reserved. + + Redistribution and use in source and binary forms, with or + without modification, is permitted pursuant to, and subject + to the license terms contained in, the Simplified BSD License + set forth in Section 4.c of the IETF Trust's Legal Provisions + Relating to IETF Documents + (http://trustee.ietf.org/license-info). + + This version of this YANG module is part of RFC 8676; see + the RFC itself for full legal notices."; + + revision 2019-11-16 { + description + "Initial revision."; + reference + "RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port + (A+P) Softwires"; + } + + feature map-e { + description + "MAP-E is an IPv6 transition mechanism for transporting IPv4 + packets across an IPv6 network using IP encapsulation. MAP-E + allows for a reduction of the amount of centralized state + using rules to express IPv4/IPv6 address mappings. This + introduces an algorithmic relationship between the IPv6 + subnet and IPv4 address. + + This feature indicates that the network element can function + as one or more MAP-E softwire instances."; + reference + "RFC 7597: Mapping of Address and Port with Encapsulation + (MAP-E)"; + } + + feature map-t { + description + "MAP-T is an IPv6 transition mechanism for transporting IPv4 + packets across an IPv6 network using IP translation. It + leverages a double stateless NAT64-based solution as well as + the stateless algorithmic address and transport layer + port mapping algorithm defined for MAP-E. + + This feature indicates that the network element can function + as one or more MAP-T softwire instances."; + reference + "RFC 7599: Mapping of Address and Port using Translation + (MAP-T)"; + } + + /* + * Groupings + */ + + grouping algorithm-instance { + description + "A collection of parameters that is used for MAP-E/MAP-T."; + leaf enable { + type boolean; + description + "Enable/disable an individual MAP-E or MAP-T rule."; + } + container algo-versioning { + description + "Version number for this algorithm instance"; + leaf version { + type uint64; + description + "A version number for the mapping algorithm + rules provided to the algorithm instance"; + } + leaf date { + type yang:date-and-time; + description + "Timestamp when the algorithm instance was activated. + + An algorithm instance may be provided with mapping + rules that may change in time (for example, increase + the size of the port set). When a party who is the victim + of abuse presents an external IP address/port, the version + of the algorithm is important because depending on + the version, a distinct customer may be identified. + + The timestamp is used as a key to find the appropriate + algorithm that was put into effect when an abuse + occurred."; + reference + "RFC 7422: Deterministic Address Mapping to Reduce + Logging in Carrier-Grade NAT Deployments"; + } + } + choice data-plane { + description + "Selects MAP-E (encapsulation) or MAP-T + (translation)"; + case encapsulation { + if-feature "map-e"; + description + "encapsulation for MAP-E"; + leaf br-ipv6-addr { + type inet:ipv6-address; + mandatory true; + description + "The IPv6 address of the MAP-E BR."; + } + } + case translation { + if-feature "map-t"; + description + "translation for MAP-T"; + leaf dmr-ipv6-prefix { + type inet:ipv6-prefix; + description + "The IPv6 prefix of the MAP-T BR."; + } + } + } + leaf ea-len { + type uint8; + mandatory true; + description + "Embedded Address (EA) bits are the IPv4 EA-bits in the IPv6 + address identifying an IPv4 prefix/address (or part thereof) + or a shared IPv4 address (or part thereof) and a port-set + identifier. The length of the EA-bits is defined as part of + a MAP rule for a MAP domain."; + } + leaf rule-ipv6-prefix { + type inet:ipv6-prefix; + mandatory true; + description + "The Rule IPv6 prefix defined in the mapping rule."; + } + leaf rule-ipv4-prefix { + type inet:ipv4-prefix; + mandatory true; + description + "The Rule IPv4 prefix defined in the mapping rule."; + } + leaf forwarding { + type boolean; + mandatory true; + description + "This parameter specifies whether the rule may be used for + forwarding; if set, this rule is used as a Forwarding + Mapping Rule (FMR); if not set, this rule is a Basic + Mapping Rule (BMR) only and must not be used for + forwarding."; + } + } + + grouping traffic-stat { + description + "Traffic statistics"; + leaf sent-ipv4-packets { + type yang:zero-based-counter64; + description + "Number of decapsulated and forwarded IPv4 packets. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf sent-ipv4-bytes { + type yang:zero-based-counter64; + description + "Decapsulated/translated IPv4 traffic sent, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf sent-ipv6-packets { + type yang:zero-based-counter64; + description + "Number of encapsulated IPv6 packets sent. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf sent-ipv6-bytes { + type yang:zero-based-counter64; + description + "Encapsulated IPv6 traffic sent, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf rcvd-ipv4-packets { + type yang:zero-based-counter64; + description + "Number of IPv4 packets received. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf rcvd-ipv4-bytes { + type yang:zero-based-counter64; + description + "IPv4 traffic received, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf rcvd-ipv6-packets { + type yang:zero-based-counter64; + description + "Number of IPv4-in-IPv6 packets received. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf rcvd-ipv6-bytes { + type yang:zero-based-counter64; + description + "IPv4-in-IPv6 traffic received, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf dropped-ipv4-packets { + type yang:zero-based-counter64; + description + "Number of IPv4 packets dropped at the + Internet-facing interface. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf dropped-ipv4-bytes { + type yang:zero-based-counter64; + description + "IPv4 traffic dropped at the Internet-facing + interface, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf dropped-ipv6-packets { + type yang:zero-based-counter64; + description + "Number of IPv4-in-IPv6 packets dropped. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf dropped-ipv6-bytes { + type yang:zero-based-counter64; + description + "IPv4-in-IPv6 traffic dropped, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf dropped-ipv4-fragments { + type yang:zero-based-counter64; + description + "Number of fragmented IPv4 packets dropped. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf dropped-ipv4-fragment-bytes { + type yang:zero-based-counter64; + description + "Fragmented IPv4 traffic dropped, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf ipv6-fragments-reassembled { + type yang:zero-based-counter64; + description + "Number of IPv6 fragments successfully reassembled. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf ipv6-fragments-bytes-reassembled { + type yang:zero-based-counter64; + description + "IPv6 fragments successfully reassembled, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf out-icmpv4-error-packets { + type yang:zero-based-counter64; + description + "Internally generated ICMPv4 error packets. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf out-icmpv4-error-bytes { + type yang:zero-based-counter64; + description + "Internally generated ICMPv4 error messages, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf out-icmpv6-error-packets { + type yang:zero-based-counter64; + description + "Internally generated ICMPv6 error packets. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + leaf out-icmpv6-error-bytes { + type yang:zero-based-counter64; + description + "Internally generated ICMPv6 error messages, in bytes. + + Discontinuities in the value of this counter can occur + at re-initialization of the management system and at + other times as indicated by the value of + 'discontinuity-time'."; + } + } + } + <CODE ENDS> + +9. Security Considerations + + The YANG modules defined in this document are designed to be accessed + via network management protocols such as NETCONF [RFC6241] or + RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport + layer, and the mandatory-to-implement secure transport is Secure + Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the + mandatory-to-implement secure transport is TLS [RFC8446]. + + The Network Configuration Access Control Model (NACM) [RFC8341] + provides the means to restrict access for particular NETCONF or + RESTCONF users to a preconfigured subset of all available NETCONF or + RESTCONF protocol operations and content. + + All data nodes defined in the YANG modules which can be created, + modified, and deleted (i.e., config true, which is the default) are + considered sensitive. Write operations (e.g., edit-config) to these + data nodes without proper protection can have a negative effect on + network operations. An attacker who is able to access the BR can + undertake various attacks, such as: + + * Setting the value of 'br-ipv6-addr' on the CE to point to an + illegitimate BR so that it can intercept all the traffic sent by a + CE. Illegitimately intercepting users' traffic is an attack with + severe implications on privacy. + + * Setting the MTU to a low value, which may increase the number of + fragments ('softwire-payload-mtu'). + + * Disabling hairpinning (i.e., setting 'enable-hairpinning' to + 'false') to prevent communications between CEs. + + * Setting 'softwire-num-max' to an arbitrary high value, which may + be exploited by a misbehaving user to perform a DoS on the binding + BR by mounting a massive number of softwires. + + * Setting 'icmpv4-rate' or 'icmpv6-rate' to a low value, which may + lead to the deactivation of ICMP messages handling. + + * Instructing the BR to install entries, which, in turn, will induce + a DDoS attack by means of the notifications generated by the BR. + This DDoS can be softened by defining a notification interval, but + given that this interval parameter can be disabled or set to a low + value by the misbehaving entity, the same problem will be + observed. + + Some of the readable data nodes in this YANG module may be considered + sensitive or vulnerable in some network environments. It is thus + important to control read access (e.g., via get, get-config, or + notification) to these data nodes. These subtrees and data nodes can + be misused to track the activity of a host: + + * the binding Table (/br-instances/binding/bind-instance/binding- + table) + + * the algorithm configuration (/br-instances/algorithm/algo- + instance/) + + Security considerations related to lw4o6, MAP-T, and MAP-E are + discussed in [RFC7596], [RFC7597], and [RFC7599] respectively. + + Security considerations given in [RFC7950] are also applicable here. + +10. IANA Considerations + + IANA has assigned the following new tunnel type under the tunnelType + subregistry of the "ifType Definitions" registry maintained in the + SMI Numbers registry [TUNNELTYPE-IANA-REGISTRY]: + + Decimal: 18 + Name: aplusp + Description: A+P encapsulation + Reference: [RFC6346] + + IANA has registered the following in the "ns" subregistry within the + "IETF XML Registry" [RFC3688]: + + URI: urn:ietf:params:xml:ns:yang:ietf-softwire-ce + Registrant Contact: The IESG. + XML: N/A; the requested URI is an XML namespace. + + URI: urn:ietf:params:xml:ns:yang:ietf-softwire-br + Registrant Contact: The IESG. + XML: N/A; the requested URI is an XML namespace. + + URI: urn:ietf:params:xml:ns:yang:ietf-softwire-common + Registrant Contact: The IESG. + XML: N/A; the requested URI is an XML namespace. + + IANA has registered the following YANG modules in the "YANG Module + Names" subregistry [RFC6020] within the "YANG Parameters" registry. + + name: ietf-softwire-ce + namespace: urn:ietf:params:xml:ns:yang:ietf-softwire-ce + prefix: softwire-ce + reference: RFC 8676 + + name: ietf-softwire-br + namespace: urn:ietf:params:xml:ns:yang:ietf-softwire-br + prefix: softwire-br + reference: RFC 8676 + + name: ietf-softwire-common + namespace: urn:ietf:params:xml:ns:yang:ietf-softwire-common + prefix: softwire-common + reference: RFC 8676 + +11. References + +11.1. Normative References + + [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, + DOI 10.17487/RFC3688, January 2004, + <https://www.rfc-editor.org/info/rfc3688>. + + [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for + the Network Configuration Protocol (NETCONF)", RFC 6020, + DOI 10.17487/RFC6020, October 2010, + <https://www.rfc-editor.org/info/rfc6020>. + + [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., + and A. Bierman, Ed., "Network Configuration Protocol + (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, + <https://www.rfc-editor.org/info/rfc6241>. + + [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure + Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, + <https://www.rfc-editor.org/info/rfc6242>. + + [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", + RFC 6991, DOI 10.17487/RFC6991, July 2013, + <https://www.rfc-editor.org/info/rfc6991>. + + [RFC7224] Bjorklund, M., "IANA Interface Type YANG Module", + RFC 7224, DOI 10.17487/RFC7224, May 2014, + <https://www.rfc-editor.org/info/rfc7224>. + + [RFC7596] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I. + Farrer, "Lightweight 4over6: An Extension to the Dual- + Stack Lite Architecture", RFC 7596, DOI 10.17487/RFC7596, + July 2015, <https://www.rfc-editor.org/info/rfc7596>. + + [RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S., + Murakami, T., and T. Taylor, Ed., "Mapping of Address and + Port with Encapsulation (MAP-E)", RFC 7597, + DOI 10.17487/RFC7597, July 2015, + <https://www.rfc-editor.org/info/rfc7597>. + + [RFC7598] Mrugalski, T., Troan, O., Farrer, I., Perreault, S., Dec, + W., Bao, C., Yeh, L., and X. Deng, "DHCPv6 Options for + Configuration of Softwire Address and Port-Mapped + Clients", RFC 7598, DOI 10.17487/RFC7598, July 2015, + <https://www.rfc-editor.org/info/rfc7598>. + + [RFC7599] Li, X., Bao, C., Dec, W., Ed., Troan, O., Matsushima, S., + and T. Murakami, "Mapping of Address and Port using + Translation (MAP-T)", RFC 7599, DOI 10.17487/RFC7599, July + 2015, <https://www.rfc-editor.org/info/rfc7599>. + + [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", + RFC 7950, DOI 10.17487/RFC7950, August 2016, + <https://www.rfc-editor.org/info/rfc7950>. + + [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF + Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, + <https://www.rfc-editor.org/info/rfc8040>. + + [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration + Access Control Model", STD 91, RFC 8341, + DOI 10.17487/RFC8341, March 2018, + <https://www.rfc-editor.org/info/rfc8341>. + + [RFC8343] Bjorklund, M., "A YANG Data Model for Interface + Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, + <https://www.rfc-editor.org/info/rfc8343>. + + [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol + Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, + <https://www.rfc-editor.org/info/rfc8446>. + + [RFC8675] Boucadair, M., Farrer, I., and R. Asati, "A YANG Data + Model for Tunnel Interface Types", RFC 8675, + DOI 10.17487/RFC8675, November 2019, + <https://www.rfc-editor.org/info/rfc8675>. + + [TUNNELTYPE-IANA-REGISTRY] + IANA, "Structure of Management Information (SMI) Numbers + (MIB Module Registrations)", + <https://www.iana.org/assignments/smi-numbers>. + +11.2. Informative References + + [RFC4213] Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms + for IPv6 Hosts and Routers", RFC 4213, + DOI 10.17487/RFC4213, October 2005, + <https://www.rfc-editor.org/info/rfc4213>. + + [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- + Stack Lite Broadband Deployments Following IPv4 + Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011, + <https://www.rfc-editor.org/info/rfc6333>. + + [RFC6346] Bush, R., Ed., "The Address plus Port (A+P) Approach to + the IPv4 Address Shortage", RFC 6346, + DOI 10.17487/RFC6346, August 2011, + <https://www.rfc-editor.org/info/rfc6346>. + + [RFC7422] Donley, C., Grundemann, C., Sarawat, V., Sundaresan, K., + and O. Vautrin, "Deterministic Address Mapping to Reduce + Logging in Carrier-Grade NAT Deployments", RFC 7422, + DOI 10.17487/RFC7422, December 2014, + <https://www.rfc-editor.org/info/rfc7422>. + + [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", + BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, + <https://www.rfc-editor.org/info/rfc8340>. + + [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., + and R. Wilton, "Network Management Datastore Architecture + (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, + <https://www.rfc-editor.org/info/rfc8342>. + + [RFC8344] Bjorklund, M., "A YANG Data Model for IP Management", + RFC 8344, DOI 10.17487/RFC8344, March 2018, + <https://www.rfc-editor.org/info/rfc8344>. + + [RFC8349] Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for + Routing Management (NMDA Version)", RFC 8349, + DOI 10.17487/RFC8349, March 2018, + <https://www.rfc-editor.org/info/rfc8349>. + + [RFC8512] Boucadair, M., Ed., Sivakumar, S., Jacquenet, C., + Vinapamula, S., and Q. Wu, "A YANG Module for Network + Address Translation (NAT) and Network Prefix Translation + (NPT)", RFC 8512, DOI 10.17487/RFC8512, January 2019, + <https://www.rfc-editor.org/info/rfc8512>. + + [RFC8513] Boucadair, M., Jacquenet, C., and S. Sivakumar, "A YANG + Data Model for Dual-Stack Lite (DS-Lite)", RFC 8513, + DOI 10.17487/RFC8513, January 2019, + <https://www.rfc-editor.org/info/rfc8513>. + +Appendix A. Configuration Examples + + The following sections provide examples of how the softwire YANG + modules can be used for configuring softwire elements. + +A.1. Configuration Example for a lw4o6 BR Binding-Table + + The lwAFTR maintains an address binding table that contains the + following 3-tuples: + + * IPv6 Address for a single lwB4 + + * Public IPv4 Address + + * Restricted port-set + + The entry has two functions: the IPv6 encapsulation of inbound IPv4 + packets destined to the lwB4 and the validation of outbound IPv4-in- + IPv6 packets received from the lwB4 for decapsulation. + + Consider an example for the following lw4o6 binding table entry: + + lwB4 Binding IPv6 Address: 2001:db8::1 + + lwB4 Binding IPv4 Address: 192.0.2.1 + + lwB4 PSID: 0x34 + + lwB4 PSID Length 8 + + BR IPv6 Address: 2001:db8:1::2 + + <br-instances> + <binding> + <bind-instance> + <name>mybinding-instance</name> + <binding-table> + <binding-entry> + <binding-ipv6info>2001:db8::1</binding-ipv6info> + <binding-ipv4-addr>192.0.2.1</binding-ipv4-addr> + <port-set> + <psid>52</psid> + <psid-len>8</psid-len> + </port-set> + <br-ipv6-addr>2001:db8:1::2</br-ipv6-addr> + </binding-entry> + </binding-table> + <softwire-num-max>1024</softwire-num-max> + <softwire-path-mru>1540</softwire-path-mru> + <softwire-payload-mtu>1500</softwire-payload-mtu> + </bind-instance> + </binding> + </br-instances> + + Figure 3: lw4o6 Binding Table Configuration XML + +A.2. Configuration Example for a MAP-E BR + + A MAP-E BR is configured with forward mapping rules for the CEs it is + serving. In this example (taken from [RFC7597], Appendix A, Example + 2), the following parameters are required: + + * Rule IPv6 Prefix + + * Rule IPv4 Prefix + + * Rule EA-bit bit length + + * IPv6 Address of MAP-BR + + The mapping rule has two functions: identifying the destination CE + IPv6 address for encapsulating inbound IPv4 packets and the + validation of outbound IPv4-in-IPv6 packets received from the CE for + de-capsulation. + + The transport type for the data plane also needs to be configured for + encapsulation to enable MAP-E and forwarding needs to be enabled. + + Consider an example for the following MAP-E Forwarding Mapping Rule: + + Data plane: encapsulation + + Rule IPv6 Prefix: 2001:db8::/40 + + Rule IPv4 Prefix: 192.0.2.0/24 + + Rule EA-bit Length: 16 + + BR IPv6 Address: 2001:db8:ffff::1 + + Figure 4 provides the example MAP-E BR configuration xml. + + <br-instances> + <algorithm> + <algo-instance> + <name>myalgo-instance</name> + <encapsulation> + <br-ipv6-addr>2001:db8:ffff::1</br-ipv6-addr> + </encapsulation> + <ea-len>16</ea-len> + <rule-ipv4-prefix>192.0.2.0/24</rule-ipv4-prefix> + <rule-ipv6-prefix>2001:db8::/40</rule-ipv6-prefix> + <forwarding>true</forwarding> + <port-set> + <psid-offset>6</psid-offset> + <psid-len>8</psid-len> + </port-set> + </algo-instance> + </algorithm> + </br-instances> + + Figure 4: MAP-E FMR Configuration XML + +A.3. lw4o6 CE Configuration Example + + This section provides XML examples for configuring a lw4o6 CE. + Examples for routing and NAT44 are also provided for convenience. + + Consider an example for the following lw4o6 CE configuration: + + lwB4 Binding IPv6 Address: 2001:db8::1 + + lwB4 Binding IPv4 Address: 192.0.2.1 + + lwB4 PSID: 0x34 + + lwB4 PSID Length 8 + + BR IPv6 Address: 2001:db8:1::2 + + <config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> + <interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces"> + <interface> + <name>lw4o6-wan</name> + <type>iana-tunnel-type:aplusp</type> + <br-ipv6-addr + xmlns="urn:ietf:params:xml:ns:yang:ietf-softwire-ce"> + 2001:db8:1::2 + </br-ipv6-addr> + <binding-ipv6info + xmlns="urn:ietf:params:xml:ns:yang:ietf-softwire-ce"> + 2001:db8::1 + </binding-ipv6info> + </interface> + </interfaces> + </config> + + Figure 5: lw4o6 CE Configuration XML + + In the example depicted in Figure 5, the interface name is defined + for the softwire tunnel. This name is then referenced by the routing + configuration for the IPv4 route. Figure 6 provides an example + configuration for the CE's IPv4 routing using the YANG module + described in [RFC8349]. + + <config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> + <routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing"> + <control-plane-protocols> + <control-plane-protocol> + <type>static</type> + <name>v4</name> + <static-routes> + <ipv4 + xmlns="urn:ietf:params:xml:ns:yang:ietf-ipv4-unicas\ + t-routing"> + <route> + <destination-prefix>0.0.0.0/0</destination-prefix> + <next-hop> + <outgoing-interface>lw4o6-wan</outgoing-interface> + </next-hop> + </route> + </ipv4> + </static-routes> + </control-plane-protocol> + </control-plane-protocols> + </routing> + </config> + + Figure 6: lw4o6 CE Routing Configuration XML + + Figure 7 provides an example configuration for the CE's NAPT44 + function using the YANG module described in [RFC8512]. + + <config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> + <nat xmlns="urn:ietf:params:xml:ns:yang:ietf-nat"> + <instances> + <instance> + <id>1</id> + <policy> + <policy-id>1</policy-id> + <external-ip-address-pool> + <pool-id>1</pool-id> + <external-ip-pool>192.0.2.1</external-ip-pool> + </external-ip-address-pool> + <port-set-restrict> + <port-set-algo> + <psid-offset>6</psid-offset> + <psid-len>8</psid-len> + <psid>52</psid> + </port-set-algo> + </port-set-restrict> + <notify-pool-usage> + <pool-id>1</pool-id> + <high-threshold>80</high-threshold> + </notify-pool-usage> + </policy> + <mapping-limits> + <limit-per-protocol> + <protocol-id>1</protocol-id> + <limit>8</limit> + </limit-per-protocol> + <limit-per-protocol> + <protocol-id>6</protocol-id> + <limit>32</limit> + </limit-per-protocol> + <limit-per-protocol> + <protocol-id>17</protocol-id> + <limit>16</limit> + </limit-per-protocol> + </mapping-limits> + <mapping-table> + <mapping-entry> + <index>1</index> + <external-src-address> + 192.0.2.1/32 + </external-src-address> + <internal-src-address> + 192.168.1.0/24 + </internal-src-address> + <transport-protocol>6</transport-protocol> + </mapping-entry> + <mapping-entry> + <index>2</index> + <external-src-address> + 192.0.2.1/32 + </external-src-address> + <internal-src-address> + 192.168.1.0/24 + </internal-src-address> + <transport-protocol>17</transport-protocol> + </mapping-entry> + <mapping-entry> + <index>3</index> + <external-src-address> + 192.0.2.1/32 + </external-src-address> + <internal-src-address> + 192.168.1.0/24 + </internal-src-address> + <transport-protocol>1</transport-protocol> + </mapping-entry> + </mapping-table> + </instance> + </instances> + </nat> + </config> + + Figure 7: lw4o6 NAT Configuration XML + +Acknowledgements + + The authors would like to thank Lishan Li, Bert Wijnen, Giles Heron, + Ole Troan, Andy Wingo, and Leo Tietz for their contributions to this + work. + + Thanks to Sheng Jiang for the review. + + Special thanks to Tom Petch and Martin Bjorklund for the detailed + review and suggestions. + +Contributors + + The following individuals are co-authors: + + Yong Cui + Tsinghua University + China + Phone: +86-10-6260-3059 + Email: cuiyong@tsinghua.edu.cn + + Qi Sun + Tsinghua University + China + Phone: +86-10-6278-5822 + Email: sunqi.ietf@gmail.com + + Linhui Sun + Tsinghua University + China + Phone: +86-10-6278-5822 + Email: lh.sunlinh@gmail.com + + Sladjana Zechlin + Deutsche Telekom AG + Germany + Email: sladjana.zechlin@telekom.de + + Rajiv Asati + Cisco Systems, Inc. + United States of America + Email: Rajiva@cisco.com + + Hao Wang + Tsinghua University + China + Phone: +86-10-6278-5822 + Email: wangh13@mails.tsinghua.edu.cn + +Authors' Addresses + + Ian Farrer (editor) + Deutsche Telekom AG + CTO-ATI, Landgrabenweg 151 + 53227 Bonn + Germany + + Email: ian.farrer@telekom.de + + + Mohamed Boucadair (editor) + Orange + 35000 Rennes + France + + Email: mohamed.boucadair@orange.com |