YANG Data Models for the DS-Lite
draft-ietf-softwire-dslite-yang-04
The information below is for an old version of the document.
| Document | Type | Active Internet-Draft (softwire WG) | |
|---|---|---|---|
| Authors | Mohamed Boucadair , Christian Jacquenet , Senthil Sivakumar | ||
| Last updated | 2017-08-02 | ||
| Replaces | draft-boucadair-softwire-dslite-yang | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | plain text xml htmlized pdfized bibtex | ||
| Reviews |
YANGDOCTORS Early review
(of
-02)
On the Right Track
|
||
| Stream | WG state | WG Document | |
| Document shepherd | Ian Farrer | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | "Ian Farrer" <ianfarrer@gmx.com> |
draft-ietf-softwire-dslite-yang-04
Network Working Group M. Boucadair
Internet-Draft C. Jacquenet
Intended status: Standards Track Orange
Expires: February 3, 2018 S. Sivakumar
Cisco Systems
August 2, 2017
YANG Data Models for the DS-Lite
draft-ietf-softwire-dslite-yang-04
Abstract
This document defines a YANG data model for the DS-Lite Address
Family Transition Router (AFTR) and Basic Bridging BroadBand (B4)
elements .
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 3, 2018.
Copyright Notice
Copyright (c) 2017 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
(http://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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2
1.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 2
2. DS-Lite YANG Data Models . . . . . . . . . . . . . . . . . . 3
3. DS-Lite AFTR YANG Module . . . . . . . . . . . . . . . . . . 4
4. DS-Lite B4 YANG Module . . . . . . . . . . . . . . . . . . . 10
5. Security Considerations . . . . . . . . . . . . . . . . . . . 13
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
8.1. Normative references . . . . . . . . . . . . . . . . . . 14
8.2. Informative references . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
This document defines a data model for DS-Lite [RFC6333], using the
YANG data modeling language [RFC6020]. Both the Address Family
Transition Router (AFTR) and Basic Bridging BroadBand (B4) elements
are covered by this specification.
DS-Lite deployment considerations are discussed in [RFC6908].
This document follows the guidelines of [RFC6087].
This document uses the common YANG types defined in [RFC6991].
1.1. Terminology
This document makes use of the terms defined in [RFC6333].
The terminology for describing YANG data models is defined in
[RFC6020].
1.2. Tree Diagrams
The meaning of the symbols in these diagrams is as follows:
o Brackets "[" and "]" enclose list keys.
o Curly braces "{" and "}" contain names of optional features that
make the corresponding node conditional.
o Abbreviations before data node names: "rw" means configuration
(read-write), "ro" state data (read-only).
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o Symbols after data node names: "?" means an optional node, "!" a
container with presence, and "*" denotes a "list" or "leaf-list".
o Parentheses enclose choice and case nodes, and case nodes are also
marked with a colon (":").
o Ellipsis ("...") stands for contents of subtrees that are not
shown.
2. DS-Lite YANG Data Models
Figure 1 depicts the YANG data model for the AFTR, while Figure 2
shows the YANG data model for the B4 element.
The AFTR model supports enabling one or more instances of the AFTR
function on a device; each instance is responsible for serving a
group of B4s. The data model assumes that each AFTR instance can: be
enable/disabled, be provisioned with dedicated configuration data,
and maintain its own mapping table. The data model assumes that
pools of IPv4 addresses can be provisioned to the AFTR. The AFTR
module augments the NAT module in [I-D.sivakumar-yang-nat].
As such, this document assumes [RFC4787][RFC5382][RFC5508] are
enabled by default. Also, the data model adheres to the
recommendations in [RFC6888] and [RFC7857]. Further, the data model
supports state migration as per [RFC7785].
PCP-related considerations are out of scope of the document. A YANG
data model for PCP is documented in [I-D.boucadair-pcp-yang].
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module: ietf-dslite-aftr
augment /nat:nat-module/nat:nat-instances/nat:nat-instance:
+--rw ipv6-address? inet:ipv6-address
+--rw ipv4-address? inet:ipv4-address
+--rw tunnel-mtu? uint16
+--rw subscriber-mask? uint8
+--rw state-migrate? boolean
+--rw max-softwire-per-subscriber? uint8
+--rw mss-clamping
| +--rw mss-clamping-enable? boolean
| +--rw mss-value? uint16
+--rw v6-v4-dscp-preservation? boolean
augment /nat:nat-module/nat:nat-instances/nat:nat-instance/nat:mapping-table/nat:mapping-entry:
+--rw b4-ip-address? inet:ipv6-address
+--rw v6-dscp? uint8
+--rw internal-v4-dscp? uint8
+--rw external-v4-dscp? uint8
Figure 1: YANG Data Model for DS-Lite AFTR
module: ietf-dslite-b4
+--rw dslite-b4
+--rw enable? boolean
+--rw dslite-b4-instances
+--rw dslite-b4-instance* [id]
+--rw id uint32
+--rw name? string
+--rw aftr-ipv6-addr inet:ipv6-address
+--rw ipv4-address? inet:ipv4-address
+--rw tunnel-mtu? uint16
+--rw v6-v4-dscp-preservation boolean
Figure 2: YANG Data Model for DS-Lite B4
3. DS-Lite AFTR YANG Module
<CODE BEGINS> file "ietf-dslite-aftr@2017-07-27.yang"
module ietf-dslite-aftr {
namespace "urn:ietf:params:xml:ns:yang:ietf-dslite-aftr";
prefix dslite-aftr;
import ietf-inet-types { prefix inet; }
import ietf-nat {
prefix nat;
}
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organization "Softwire Working Group";
contact
"Mohamed Boucadair <mohamed.boucadair@orange.com>
Christian Jacquenet <christian.jacquenet@orange.com>
Senthil Sivakumar <ssenthil@cisco.com>";
description
"This module is a YANG module for DS-Lite AFTR
implementations.
Copyright (c) 2017 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 XXXX; see
the RFC itself for full legal notices.";
revision 2017-07-27 {
description "Redesign the module as an augment of the NAT YANG module.";
reference "-ietf-04";
}
revision 2017-07-03 {
description "Fix some minor points.";
reference "-ietf-03";
}
revision 2017-01-03 {
description "Fixed a compilation error:
https://github.com/mbj4668/pyang/issues/296.";
reference "-ietf-02";
}
revision 2016-11-14 {
description "Integrates the comments from Ian:
add B4 module, add an MSS leaf, add more details about
logging protocols, and other edits.";
reference "-ietf-01";
}
revision 2016-07-27 {
description "-00 IETF version.";
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reference "-ietf-00";
}
revision 2016-06-13 {
description "Update the module.";
reference "-04";
}
revision 2015-12-16 {
description "Fix an error.";
reference "-03";
}
revision 2015-09-01 {
description "Add port threshold notifications.";
reference "-02";
}
revision 2015-08-31 {
description "Fix a timeout issue.";
reference "-01";
}
revision 2015-08-17 {
description "First spec.";
reference "-00";
}
// Augment NAT module with AFTR parameters
augment "/nat:nat-module/nat:nat-instances/nat:nat-instance" {
description
"Augments NAT module with AFTR parameters.";
leaf ipv6-address {
type inet:ipv6-address;
description
"IPv6 address of the dslite-aftr.";
reference
"RFC 6333.";
}
leaf ipv4-address {
type inet:ipv4-address;
default "192.0.0.1";
description
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"IPv4 address of the DS-Lite AFTR.
192.0.0.1 is reserved for the AFTR element.
This address can be used to report ICMP
problems and will appear in traceroute
outputs.";
reference
"RFC 6333.";
}
leaf tunnel-mtu {
type uint16;
description
"Configures a tunnel MTU.
[RFC6908] specifies that since
fragmentation and reassembly is not
optimal, the operator should do
everything possible to eliminate
the need for it. If the operator uses
simple IPv4-in-IPv6 softwire, it is
recommended that the MTU size of the IPv6
network between the B4 and the AFTR
accounts for the additional overhead
(40 bytes).";
reference
"RFC 6908.";
}
leaf subscriber-mask {
type uint8 {
range "0 .. 128";
}
default "56";
description
"The subscriber-mask is an integer that indicates
the length of significant bits to be applied on
the source IPv6 address (internal side) to
unambiguously identify a CPE.
Subscriber-mask is a system-wide configuration
parameter that is used to enforce generic
per-subscriber policies (e.g., port-quota).
The enforcement of these generic policies does not
require the configuration of every subscriber's prefix.
Example: suppose the 2001:db8:100:100::/56 prefix is
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assigned to a DS-Lite enabled CPE. Suppose also that the
2001:db8:100:100::1 is the IPv6 address used by the
B4 that resides in that CPE. When the AFTR
receives a packet from this client,
it applies the subscriber-mask (e.g., 56) on
the source IPv6 address to compute the associated prefix
for this client (that is 2001:db8:100:100::/56). Then,
the AFTR enforces policies based on that prefix
(2001:db8:100:100::/56), not on the exact
source IPv6 address";
reference
"RFC 7785.";
}
leaf state-migrate {
type boolean;
default true;
description
"State migration is enabled by default.";
reference
"RFC 7785.";
}
leaf max-softwire-per-subscriber {
type uint8;
default 1;
description
"Configures the maximum softwire per subscriber
feature.
A subscriber is uniquely identified by means
of subscriber-mask.
This policy aims to prevent a misbehaving
subscriber from mounting several DS-Lite
softwires that would consume additional AFTR
resources (e.g., get more external ports if
the quota were enforced on a per-softwire basis,
consume extra processing due to a large number
of active softwires).";
reference
"Section 4 of RFC 7785.";
}
container mss-clamping {
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description
"MSS rewriting configuration.";
leaf mss-clamping-enable {
type boolean;
description
"Enable/disable MSS rewriting feature.";
}
leaf mss-value {
type uint16;
units "octets";
description
"Sets the MSS value to be used for
MSS rewriting.";
}
}
leaf v6-v4-dscp-preservation {
type boolean;
description
"Copies the DSCP value from the IPv6 header
and vice versa.
According to Section 2.10 of [RFC6908],
operators should use this model
by provisioning the network such that
the AFTR copies the DSCP value in the IPv4
header to the Traffic Class field in
the IPv6 header, after the encapsulation
for the downstream traffic.";
reference
"Section 2.10 of RFC 6908.";
}
}
// Augment NAT mapping entry: Extended NAT44 mapping Entry
augment "/nat:nat-module/nat:nat-instances/nat:nat-instance/nat:mapping-table/nat:mapping-entry"{
description
"Augments the NAT mapping table with DS-Lite specifics.";
leaf b4-ip-address {
type inet:ipv6-address;
description
"Corresponds to the IPv6 address
used by the B4 element.";
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reference
"RFC 6333.";
}
leaf v6-dscp {
type uint8;
description
"DSCP value used at the softwire level
(i.e., IPv6 header).";
}
leaf internal-v4-dscp {
type uint8;
description
"DSCP value of the encapsulated IPv4 packet.";
}
leaf external-v4-dscp {
type uint8;
description
"DSCP value of the translated IPv4 packet
as marked by the AFTR.";
}
}
}
<CODE ENDS>
4. DS-Lite B4 YANG Module
<CODE BEGINS> file "ietf-dslite-b4@2017-07-27.yang"
module ietf-dslite-b4 {
namespace "urn:ietf:params:xml:ns:yang:ietf-dslite-b4";
prefix dslite-b4;
import ietf-inet-types { prefix inet; }
organization "Softwire Working Group";
contact
"Mohamed Boucadair <mohamed.boucadair@orange.com>
Christian Jacquenet <christian.jacquenet@orange.com>
Senthil Sivakumar <ssenthil@cisco.com>";
description
"This module is a YANG module for DS-Lite B4 implementations.
Copyright (c) 2017 IETF Trust and the persons identified as
authors of the code. All rights reserved.
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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 XXXX; see
the RFC itself for full legal notices.";
revision 2017-07-27 {
description "Separate B4 from AFTR.";
reference "-ietf-04";
}
container dslite-b4 {
description
"dslite-b4";
leaf enable {
type boolean;
description
"Enable/disable dslite-b4 function.";
}
container dslite-b4-instances {
description
"dslite-b4 instances";
list dslite-b4-instance {
key "id";
description
"a dslite-b4 instance.";
leaf id {
type uint32;
description
"dslite-b4 instance identifier.";
}
leaf name {
type string;
description
"A name associated with the dslite-b4 instance.";
}
leaf aftr-ipv6-addr {
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type inet:ipv6-address;
mandatory true;
description
"The AFTR's IPv6 address.";
reference
"RFC 6333.";
}
leaf ipv4-address {
type inet:ipv4-address;
default "192.0.0.2";
description
"IPv4 address of the DS-Lite B4.
192.0.0.0/29 is reserved for the B4 element
[RFC6333].
This address can be used to report ICMP
problems and will appear in traceroute
outputs.";
reference
"RFC 6333.";
}
leaf tunnel-mtu {
type uint16;
description
"Configures a tunnel MTU.
[RFC6908] specifies that since
fragmentation and reassembly is not
optimal, the operator should do
everything possible to eliminate
the need for it. If the operator uses
simple IPv4-in-IPv6 softwire, it is
recommended that the MTU size of the IPv6
network between the B4 and the AFTR
accounts for the additional overhead
(40 bytes).";
reference
"RFC 6908.";
}
leaf v6-v4-dscp-preservation {
type boolean;
mandatory true;
description
"Copies the DSCP value from the IPv6 header
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and vice versa.
According to Section 2.10 of [RFC6908],
operators should use this model
by provisioning the network such that
the AFTR copies the DSCP value in the IPv4
header to the Traffic Class field in
the IPv6 header, after the encapsulation
for the downstream traffic.";
}
}
}
}
}
<CODE ENDS>
5. Security Considerations
The YANG module defined in this memo is designed to be accessed via
the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the
secure transport layer and the support of SSH is mandatory to
implement secure transport [RFC6242]. The NETCONF access control
model [RFC6536] provides means to restrict access for particular
NETCONF users to a pre-configured subset of all available NETCONF
protocol operations and contents.
All data nodes defined in the YANG module which can be created,
modified and deleted (i.e., config true, which is the default).
These data nodes are considered sensitive. Write operations (e.g.,
edit-config) applied to these data nodes without proper protection
can negatively affect network operations.
6. IANA Considerations
This document requests IANA to register the following URIs in the
"IETF XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-dslite-aftr
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-dslite-b4
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
This document requests IANA to register the following YANG modules in
the "YANG Module Names" registry [RFC6020].
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name: ietf-dslite-aftr
namespace: urn:ietf:params:xml:ns:yang:ietf-dslite-aftr
prefix: dslite-aftr
reference: RFC XXXX
name: ietf-dslite-b4
namespace: urn:ietf:params:xml:ns:yang:ietf-dslite-b4
prefix: dslite-b4
reference: RFC XXXX
7. Acknowledgements
Thanks to Q. Wu for identifying a compiling error.
Many thanks to Ian Farrer for the review and comments.
8. References
8.1. Normative references
[I-D.sivakumar-yang-nat]
Sivakumar, S., Boucadair, M., and S. Vinapamula, "YANG
Data Model for Network Address Translation (NAT)", draft-
sivakumar-yang-nat-07 (work in progress), July 2017.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<http://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,
<http://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,
<http://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,
<http://www.rfc-editor.org/info/rfc6242>.
[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,
<http://www.rfc-editor.org/info/rfc6333>.
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[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536,
DOI 10.17487/RFC6536, March 2012,
<http://www.rfc-editor.org/info/rfc6536>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<http://www.rfc-editor.org/info/rfc6991>.
8.2. Informative references
[I-D.boucadair-pcp-yang]
Boucadair, M., Jacquenet, C., Sivakumar, S., and S.
Vinapamula, "YANG Data Models for the Port Control
Protocol (PCP)", draft-boucadair-pcp-yang-04 (work in
progress), May 2017.
[RFC4787] Audet, F., Ed. and C. Jennings, "Network Address
Translation (NAT) Behavioral Requirements for Unicast
UDP", BCP 127, RFC 4787, DOI 10.17487/RFC4787, January
2007, <http://www.rfc-editor.org/info/rfc4787>.
[RFC5382] Guha, S., Ed., Biswas, K., Ford, B., Sivakumar, S., and P.
Srisuresh, "NAT Behavioral Requirements for TCP", BCP 142,
RFC 5382, DOI 10.17487/RFC5382, October 2008,
<http://www.rfc-editor.org/info/rfc5382>.
[RFC5508] Srisuresh, P., Ford, B., Sivakumar, S., and S. Guha, "NAT
Behavioral Requirements for ICMP", BCP 148, RFC 5508,
DOI 10.17487/RFC5508, April 2009,
<http://www.rfc-editor.org/info/rfc5508>.
[RFC6087] Bierman, A., "Guidelines for Authors and Reviewers of YANG
Data Model Documents", RFC 6087, DOI 10.17487/RFC6087,
January 2011, <http://www.rfc-editor.org/info/rfc6087>.
[RFC6888] Perreault, S., Ed., Yamagata, I., Miyakawa, S., Nakagawa,
A., and H. Ashida, "Common Requirements for Carrier-Grade
NATs (CGNs)", BCP 127, RFC 6888, DOI 10.17487/RFC6888,
April 2013, <http://www.rfc-editor.org/info/rfc6888>.
[RFC6908] Lee, Y., Maglione, R., Williams, C., Jacquenet, C., and M.
Boucadair, "Deployment Considerations for Dual-Stack
Lite", RFC 6908, DOI 10.17487/RFC6908, March 2013,
<http://www.rfc-editor.org/info/rfc6908>.
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[RFC7785] Vinapamula, S. and M. Boucadair, "Recommendations for
Prefix Binding in the Context of Softwire Dual-Stack
Lite", RFC 7785, DOI 10.17487/RFC7785, February 2016,
<http://www.rfc-editor.org/info/rfc7785>.
[RFC7857] Penno, R., Perreault, S., Boucadair, M., Ed., Sivakumar,
S., and K. Naito, "Updates to Network Address Translation
(NAT) Behavioral Requirements", BCP 127, RFC 7857,
DOI 10.17487/RFC7857, April 2016,
<http://www.rfc-editor.org/info/rfc7857>.
Authors' Addresses
Mohamed Boucadair
Orange
Rennes 35000
France
EMail: mohamed.boucadair@orange.com
Christian Jacquenet
Orange
Rennes 35000
France
EMail: christian.jacquenet@orange.com
Senthil Sivakumar
Cisco Systems
7100-8 Kit Creek Road
Research Triangle Park, North Carolina 27709
USA
Phone: +1 919 392 5158
EMail: ssenthil@cisco.com
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