< draft-templin-atn-aero-interface-04.txt   draft-templin-atn-aero-interface-05.txt >
Network Working Group F. Templin, Ed. Network Working Group F. Templin, Ed.
Internet-Draft Boeing Research & Technology Internet-Draft Boeing Research & Technology
Intended status: Standards Track A. Whyman Intended status: Standards Track A. Whyman
Expires: December 31, 2019 MWA Ltd c/o Inmarsat Global Ltd Expires: February 7, 2020 MWA Ltd c/o Inmarsat Global Ltd
June 29, 2019 August 6, 2019
Transmission of IPv6 Packets over Aeronautical ("aero") Interfaces Transmission of IPv6 Packets over Aeronautical ("aero") Interfaces
draft-templin-atn-aero-interface-04.txt draft-templin-atn-aero-interface-05.txt
Abstract Abstract
Mobile nodes (e.g., aircraft of various configurations) communicate Mobile nodes (e.g., aircraft of various configurations) communicate
with networked correspondents over multiple access network data links with networked correspondents over multiple access network data links
and configure mobile routers to connect their on-board networks. and configure mobile routers to connect their on-board networks.
Mobile nodes configure a virtual interface (termed the "aero Mobile nodes connect to access networks using either the classic or
interface") as a thin layer over their underlying data link mobility service-enabled link model. This document specifies the
interfaces. This document specifies the transmission of IPv6 packets transmission of IPv6 packets over aeronautical ("aero") interfaces.
over aeronautical ("aero") interfaces.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 31, 2019. This Internet-Draft will expire on February 7, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Aeronautical ("aero") Interface Model . . . . . . . . . . . . 4 4. Aeronautical ("aero") Interface Model . . . . . . . . . . . . 4
5. Maximum Transmission Unit . . . . . . . . . . . . . . . . . . 6 5. Maximum Transmission Unit . . . . . . . . . . . . . . . . . . 6
6. Frame Format . . . . . . . . . . . . . . . . . . . . . . . . 6 6. Frame Format . . . . . . . . . . . . . . . . . . . . . . . . 6
7. Link-Local Addresses . . . . . . . . . . . . . . . . . . . . 6 7. Link-Local Addresses . . . . . . . . . . . . . . . . . . . . 6
8. Address Mapping - Unicast . . . . . . . . . . . . . . . . . . 7 8. Address Mapping - Unicast . . . . . . . . . . . . . . . . . . 8
9. Address Mapping - Multicast . . . . . . . . . . . . . . . . . 9 9. Address Mapping - Multicast . . . . . . . . . . . . . . . . . 11
10. Conceptual Sending Algorithm . . . . . . . . . . . . . . . . 9 10. Address Mapping for IPv6 Neighbor Discovery Messages . . . . 11
10.1. Multiple Aero Interfaces . . . . . . . . . . . . . . . . 10 11. Conceptual Sending Algorithm . . . . . . . . . . . . . . . . 12
11. Router and Prefix Discovery . . . . . . . . . . . . . . . . . 11 11.1. Multiple Aero Interfaces . . . . . . . . . . . . . . . . 13
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 12. Router Discovery and Prefix Assertion . . . . . . . . . . . . 13
13. Security Considerations . . . . . . . . . . . . . . . . . . . 13 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 14. Security Considerations . . . . . . . . . . . . . . . . . . . 16
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16
15.1. Normative References . . . . . . . . . . . . . . . . . . 14 16. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
15.2. Informative References . . . . . . . . . . . . . . . . . 15 16.1. Normative References . . . . . . . . . . . . . . . . . . 17
Appendix A. Aero Option Extensions for Special-Purpose Links . . 15 16.2. Informative References . . . . . . . . . . . . . . . . . 18
Appendix B. Prefix Length Considerations . . . . . . . . . . . . 16 Appendix A. Aero Option Extensions for Special-Purpose Links . . 19
Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 17 Appendix B. Prefix Length Considerations . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction 1. Introduction
Mobile Nodes (MNs) such as aircraft of various configurations may Mobile Nodes (MNs) such as aircraft of various configurations may
have multiple data links for communicating with networked have multiple data links for communicating with networked
correspondents. These data links often have differing performance, correspondents. These data links often have differing performance,
cost and availability characteristics that can change dynamically cost and availability characteristics that can change dynamically
according to mobility patterns, flight phases, proximity to according to mobility patterns, flight phases, proximity to
infrastructure, etc. infrastructure, etc.
Each MN receives an IPv6 Mobile Network Prefix (MNP) that can be used Each MN receives an IPv6 Mobile Network Prefix (MNP) that can be used
by on-board networks regardless of the access network data links by on-board networks regardless of the access network data links
selected for data transport. The MN performs router discovery the selected for data transport. The MN performs router discovery the
same as for customer edge routers [RFC7084], and acts as a mobile same as for customer edge routers [RFC7084], and acts as a mobile
router on behalf of its on-board networks. A virtual interface router on behalf of its on-board networks. The MN connects to access
(termed the "aero interface") is configured as a thin layer over the networks using either the classic [RFC4861] or Mobility Service (MS)-
underlying access network interfaces. enabled link model.
The aero interface is therefore the only interface abstraction In the classic model, all IPv6 Neighbor Discovery (IPv6 ND) messaging
exposed to the IPv6 layer and behaves according to the Non-Broadcast, is directly over native access network interfaces managed according
Multiple Access (NBMA) interface principle, while underlying access to the weak end system model. The MN discovers neighbors on the link
network interfaces appear as link layer communication channels in the through link-scoped multicast and/or unicast transmissions that map
architecture. The aero interface connects to a virtual overlay cloud to their corresponding link layer addresses per standard address
service known as the "aero link". resolution / mapping procedures. The MN then coordinates with
mobility agents located in the larger Internetwork beyond the first-
hop access links according the on-board mobility function. This
arrangement requires the MN to engage in active mobility messaging on
its own behalf and with no assistance from the access network.
In the MS-enabled model, a virtual interface (termed the "aero
interface") is configured as a thin layer over the underlying access
network interfaces. The aero interface is therefore the only
interface abstraction exposed to the IPv6 layer and behaves according
to the Non-Broadcast, Multiple Access (NBMA) interface principle,
while underlying access network interfaces appear as link layer
communication channels in the architecture. The aero interface
connects to a virtual overlay cloud service known as the "aero link".
Each aero link has one or more associated Mobility Service Prefixes Each aero link has one or more associated Mobility Service Prefixes
(MSPs) that identify the link. An MSP is an aggregated IPv6 prefix (MSPs) that identify the link. An MSP is an aggregated IPv6 prefix
from which aero link MNPs are derived. If the MN connects to from which aero link MNPs are derived. If the MN connects to
multiple aero links, then it configures a separate aero interface for multiple aero links, then it configures a separate aero interface for
each link. each link.
The aero interface interacts with the ground domain Mobility Service The aero interface interacts with the ground-domain MS through IPv6
(MS) through control message exchanges based on IPv6 Neighbor ND control message exchanges [RFC4861]. The MS tracks MN movements
Discovery [RFC4861]. The MS tracks MN movements and represents their and represents their MNPs in a global routing or mapping system.
MNPs in a global routing or mapping system.
The aero interface provides a traffic engineering nexus for guiding The aero interface provides a traffic engineering nexus for guiding
inbound and outbound traffic to the correct underlying interface(s). inbound and outbound traffic to the correct underlying interface(s).
The IPv6 layer sees the aero interface as a point of connection to The IPv6 layer sees the aero interface as a point of connection to
the aero link; if there are multiple aero links (i.e., multiple the aero link; if there are multiple aero links (i.e., multiple
MS's), the IPv6 layer will see multiple aero interfaces. MS's), the IPv6 layer will see multiple aero interfaces.
This document specifies the transmission of IPv6 packets [RFC8200] This document specifies the transmission of IPv6 packets [RFC8200]
and MN/MS control messaging over aeronautical ("aero") interfaces. and MN/MS control messaging over aeronautical ("aero") interfaces in
the MS-enabled link model, but also includes all necessary details
for MN operation in the classic link model.
2. Terminology 2. Terminology
The terminology in the normative references applies; especially, the The terminology in the normative references applies; especially, the
terms "link" and "interface" are the same as defined in the IPv6 terms "link" and "interface" are the same as defined in the IPv6
[RFC8200] and IPv6 Neighbor Discovery (ND) [RFC4861] specifications. [RFC8200] and IPv6 Neighbor Discovery (ND) [RFC4861] specifications.
The following terms are defined within the scope of this document: The following terms are defined within the scope of this document:
Access Network (ANET) Access Network (ANET)
skipping to change at page 4, line 33 skipping to change at page 4, line 47
3. Requirements 3. Requirements
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. Lower case document are to be interpreted as described in [RFC2119]. Lower case
uses of these words are not to be interpreted as carrying RFC2119 uses of these words are not to be interpreted as carrying RFC2119
significance. significance.
4. Aeronautical ("aero") Interface Model 4. Aeronautical ("aero") Interface Model
An aero interface is a Mobile Node (MN) virtual interface configured An aero interface is a MN virtual interface configured over one or
over one or more ANET interfaces, which may be physical (e.g., an more ANET interfaces, which may be physical (e.g., an aeronautical
aeronautical radio link) or virtual (e.g., an Internet or higher- radio link) or virtual (e.g., an Internet or higher-layer "tunnel").
layer "tunnel"). The MN coordinates with the aero link Mobility The MN coordinates with the MS through IPv6 ND message exchanges.
Service (MS) through Router Solicitation (RS) / Router Advertisement
(RA) and Neighbor Solicitation (NS) / Neighbor Advertisement (NA)
message exchanges.
The aero interface architectural layering model is the same as in The aero interface architectural layering model is the same as in
[RFC7847], and augmented as shown in Figure 1. The IPv6 layer [RFC7847], and augmented as shown in Figure 1. The IPv6 layer
therefore sees the aero interface as a single network layer interface therefore sees the aero interface as a single network layer interface
with multiple underlying ANET interfaces that appear as link layer with multiple underlying ANET interfaces that appear as link layer
communication channels in the architecture. communication channels in the architecture.
+----------------------------+ +----------------------------+
| TCP/UDP | | TCP/UDP |
Session-to-IP +---->| | Session-to-IP +---->| |
skipping to change at page 5, line 37 skipping to change at page 5, line 43
o since aero interface link-local addresses are uniquely derived o since aero interface link-local addresses are uniquely derived
from an MNP (see: Section 7, no Duplicate Address Detection (DAD) from an MNP (see: Section 7, no Duplicate Address Detection (DAD)
messaging is necessary over the aero interface. messaging is necessary over the aero interface.
o ANET interfaces can remain unnumbered in environments where o ANET interfaces can remain unnumbered in environments where
communications are coordinated entirely over the aero interface. communications are coordinated entirely over the aero interface.
o as ANET interface properties change (e.g., link quality, cost, o as ANET interface properties change (e.g., link quality, cost,
availability, etc.), any active ANET interface can be used to availability, etc.), any active ANET interface can be used to
update the profiles of multiple additional ANET interfaces in a update the profiles of multiple additional ANET interfaces in a
single RS/RA message exchange. This allows for timely adaptation single message. This allows for timely adaptation and service
and service continuity under dynamically changing conditions. continuity under dynamically changing conditions.
o coordinating ANET interfaces in this way allows them to be o coordinating ANET interfaces in this way allows them to be
represented in a unified MS profile with provisions for mobility represented in a unified MS profile with provisions for mobility
and multilink operations. and multilink operations.
o exposing a single virtual interface abstraction to the IPv6 layer o exposing a single virtual interface abstraction to the IPv6 layer
allows for traffic engineering (including QoS based link allows for traffic engineering (including QoS based link
selection, packet replication, load balancing, etc.) at the link selection, packet replication, load balancing, etc.) at the link
layer while still permitting queuing at the IPv6 layer based on, layer while still permitting queuing at the IPv6 layer based on,
e.g., traffic class, flow label, etc. e.g., traffic class, flow label, etc.
o the IPv6 layer sees the aero interface as a point of connection to o the IPv6 layer sees the aero interface as a point of connection to
the aero link; if there are multiple aero links (i.e., multiple the aero link; if there are multiple aero links (i.e., multiple
MS's), the IPv6 layer will see multiple aero interfaces. MS's), the IPv6 layer will see multiple aero interfaces.
Other opportunities are discussed in [RFC7847]. Other opportunities are discussed in [RFC7847].
5. Maximum Transmission Unit 5. Maximum Transmission Unit
The aero interface and all underlying ANET interfaces MUST configure The aero interface and all underlying ANET interfaces MUST configure
an MTU of at least 1280 bytes [RFC8200]. The aero interface SHOULD an MTU of at least 1280 bytes as required for all IPv6 interfaces
configure an MTU based on the largest MTU among all ANET interfaces. [RFC8200]. The aero interface SHOULD configure an MTU based on the
If the aero interface receives an RA message with an MTU option, it largest MTU among all ANET interfaces. If the aero interface
configures this new value regardless of any ANET interface MTUs. receives a IPv6 ND Router Advertisement (RA) message with an MTU
option, it configures this new value regardless of any ANET interface
MTUs.
The aero interface can return internally-generated ICMPv6 "Packet Too The aero interface can return internally-generated ICMPv6 "Packet Too
Big" messages for packets that are no larger than the aero interface Big" messages for packets that fit within the aero interface MTU but
MTU but too large to traverse the selected underlying ANET interface. are too large for the selected underlying ANET interface. This
This ensures that the MTU is adaptive and reflects the ANET interface ensures that the MTU is adaptive and reflects the ANET interface used
used for a given data flow. The underlying ANET interface can for a given data flow.
instead employ link-layer fragmentation at a layer below IPv6 so that
packets as large as the aero interface MTU can be accommodated. This Underlying ANET interfaces can employ link-layer fragmentation at a
ensures that no packets are lost due to a size restrction in either layer below IPv6 so that packets as large as the aero interface MTU
the uplink or downlink direction. can be accommodated. This ensures that no packets are lost due to a
size restriction in either the uplink or downlink direction.
6. Frame Format 6. Frame Format
The aero interface transmits IPv6 packets according to the native The aero interface transmits IPv6 packets according to the native
frame format of each underlying ANET interface. For example, for an frame format of each underlying ANET interface. For example, for
Ethernet interface the frame format is exactly as specified in Ethernet-compatible interfaces the frame format is specified in
[RFC2464], for tunnels over IPv6 the frame format is exactly as [RFC2464], for aeronautical radio interfaces the frame format is
specified in standards such as ICAO Doc 9776 (VDL Mode 2 Technical
Manual), for tunnels over IPv6 the frame format is exactly as
specified in [RFC2473], etc. specified in [RFC2473], etc.
7. Link-Local Addresses 7. Link-Local Addresses
A MN "aero address" is an IPv6 link-local address with an interface A MN "aero address" is an IPv6 link-local address with an interface
identifier based on its assigned MNP. MN aero addresses begin with identifier based on its assigned MNP. MN aero addresses begin with
the prefix fe80::/64 followed by a 64-bit prefix taken from the MNP the prefix fe80::/64 followed by a 64-bit prefix taken from the MNP
(see: Appendix B). For example, for the MNP: (see: Appendix B). For example, for the MNP:
2001:db8:1000:2000::/56 2001:db8:1000:2000::/56
skipping to change at page 7, line 6 skipping to change at page 7, line 18
fe80::2001:db8:1000:2001 fe80::2001:db8:1000:2001
fe80::2001:db8:1000:2002 fe80::2001:db8:1000:2002
... etc. ... ... etc. ...
fe80::2001:db8:1000:20ff fe80::2001:db8:1000:20ff
When the MN configures aero addresses from its MNP, it assigns them When the MN configures aero addresses from its MNP, it assigns them
to the aero interface. The lowest-numbered aero address serves as to each ANET interface (and also to the Aero interface in the MS-
the "base" address (for example, for the MNP 2001:db8:1000:2000::/56 enabled model). The lowest-numbered aero address serves as the
the base aero address is fe80::2001:db8:1000:2000). The MN uses the "base" address (for example, for the MNP 2001:db8:1000:2000::/56 the
base aero address for IPv6 ND messaging, but accepts packets destined base aero address is fe80::2001:db8:1000:2000). The MN uses the base
to all aero addresses equally (i.e., the same as for any multi- aero address for IPv6 ND messaging, but accepts packets destined to
addressed IPv6 interface). all aero addresses equally (i.e., the same as for any multi-addressed
IPv6 interface).
MS aero addresses are allocated from the range fe80::/96, and MUST be In the MS-enabled link model, MS endpoint (MSE) aero addresses are
managed for uniqueness by the collective aero link administrative allocated from the range fe80::/96, and MUST be managed for
authorities. Each address represents a distinct service endpoint in uniqueness by the collective aero link administrative authorities.
the MS. The lower 32 bits of the address includes a unique integer The lower 32 bits of the address includes a unique integer value,
value, e.g., fe80::1, fe80::2, fe80::3, etc. The address fe80:: is e.g., fe80::1, fe80::2, fe80::3, etc. The address fe80:: is reserved
reserved as the IPv6 link-local Subnet Router Anycast address as the IPv6 link-local Subnet Router Anycast address [RFC4291], and
[RFC4291], and the address fe80::ffff:ffff is reserved as the the address fe80::ffff:ffff is reserved as the MSE discovery address;
unspecified aero address; hence, these values are not available for hence, these values are not available for general assignment.
general assignment.
In the classic link model, ANET link devices number their interface
from the range fe80::/96 the same as above except that these
addresses need not be managed for uniqueness outside of the local
ANET link. It is therefore possible that different ANET links could
reuse numbers from the fe80::/96 space since the addresses are link-
scope only.
In a mixed model, both the classic and MS-enabled numbering schemes
can be used without conflict within the same ANET, as the two
services would be conducted as ships in the night. A mix of MNs
operating according to classic and MS-enabled models could then
operate within the same ANETs without interference.
Since MN aero addresses are guaranteed unique by the nature of the Since MN aero addresses are guaranteed unique by the nature of the
unique MNP delegation, aero interfaces set the autoconfiguration unique MNP delegation, aero interfaces set the autoconfiguration
variable DupAddrDetectTransmits to 0 [RFC4862]. variable DupAddrDetectTransmits to 0 [RFC4862].
8. Address Mapping - Unicast 8. Address Mapping - Unicast
Each aero interface maintains a neighbor cache for tracking per- Aero interfaces maintain a neighbor cache for tracking per-neighbor
neighbor state the same as for any IPv6 interface. The aero state the same as for any IPv6 interface and use the link-local
interface uses standard IPv6 Neighbor Discovery (ND) messaging address format specified in Section 7. IPv6 Neighbor Discovery (ND)
[RFC4861]. [RFC4861] messages on aero interfaces use the native Source/Target
IPv6 ND messages on aero interfaces use the native Source/Target
Link-Layer Address Option (S/TLLAO) formats of the underlying ANET Link-Layer Address Option (S/TLLAO) formats of the underlying ANET
interfaces (e.g., for Ethernet the S/TLLAO is specified in interfaces (e.g., for Ethernet the S/TLLAO is specified in
[RFC2464]). [RFC2464]).
Aero interfaces also use the link-local address format specified in MNs such as aircraft typically have many wireless data link types
Section 7, and aero interface IPv6 ND messages include aero options (e.g. satellite-based, cellular, terrestrial, air-to-air directional,
formatted as shown in Figure 2: etc.) with diverse performance, cost and availability properties.
The aero interface would therefore appear to have multiple link layer
connections, and may include information for multiple ANET interfaces
in a single message exchange.
Aero interfaces use a new IPv6 ND options called the "Aero
Registration (AR)" option (type TBD). MNs include the AR option in
Router Solicitation (RS) and/or unsolicited Neighbor Advertisement
(uNA) messages to request registration/deregistration, and the MS
includes the AR option in Router Advertisement (RA) messages to
acknowledge the MN's registration/deregistration.
MNs send RS/uNA messages that include AR options formatted as shown
in Figure 2:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length = 3 | Prefix Length |S|R|D| Reserved| | Type | Length | Prefix Length |R| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ifindex | Reserved | | Nonce |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ifIndex [1] |P00|P01|P02|P03|P04|P05|P06|P07|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P08|P09|P10|P11|P12|P13|P14|P15|P16|P17|P18|P19|P20|P21|P22|P23|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P24|P25|P26|P27|P28|P29|P30|P31|P32|P33|P34|P35|P36|P37|P38|P39|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P40|P41|P42|P43|P44|P45|P46|P47|P48|P49|P50|P51|P52|P53|P54|P55|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P56|P57|P58|P59|P60|P61|P62|P63| ifIndex [2] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P00|P01|P02|P03|P04|P05|P06|P07|P08|P09|P10|P11|P12|P13|P14|P15|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P16|P17|P18|P19|P20|P21|P22|P23|P24|P25|P26|P27|P28|P29|P30|P31|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P32|P33|P34|P35|P36|P37|P38|P39|P40|P41|P42|P43|P44|P45|P46|P47|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P48|P49|P50|P51|P52|P53|P54|P55|P56|P57|P58|P59|P60|P61|P62|P63|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...
... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... | ifIndex [N] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P00|P01|P02|P03|P04|P05|P06|P07|P08|P09|P10|P11|P12|P13|P14|P15| |P00|P01|P02|P03|P04|P05|P06|P07|P08|P09|P10|P11|P12|P13|P14|P15|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P16|P17|P18|P19|P20|P21|P22|P23|P24|P25|P26|P27|P28|P29|P30|P31| |P16|P17|P18|P19|P20|P21|P22|P23|P24|P25|P26|P27|P28|P29|P30|P31|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P32|P33|P34|P35|P36|P37|P38|P39|P40|P41|P42|P43|P44|P45|P46|P47| |P32|P33|P34|P35|P36|P37|P38|P39|P40|P41|P42|P43|P44|P45|P46|P47|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P48|P49|P50|P51|P52|P53|P54|P55|P56|P57|P58|P59|P60|P61|P62|P63| |P48|P49|P50|P51|P52|P53|P54|P55|P56|P57|P58|P59|P60|P61|P62|P63|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... (0 - 6 octets of trailing zero padding) ...
Figure 2: Aero Option Format Figure 2: Aero Registration (AR) Option Format in RS/uNA Messages
In this format: In this format:
o Type is set to TBD (to be assigned by IANA). o Type is set to TBD.
o Length is set to the constant value '3' (i.e., 3 units of 8 o Length is set to the value (2.25*N + 1), where N is the number of
octets). ifIndex tuples. Length is incremented to the next highest integer
value, and 0-6 octets of trailing zero padding are added to the
end of the option to produce an integral number of 8-octet units.
o Prefix Length is set to the length of the MNP embedded in the MN's o Prefix Length is set to the length of the MNP embedded in the MN's
aero address. For RS messages, the MS validates the MNP aero address.
assertion, then announces the MNP in the routing system and
returns an RA withn aero option and a Router Lifetime set to the
MNP assertion lifetime.
o S (the 'Source' bit) is set to '1' in the aero options of an ND o R is set to '1' to request registration or set to '0' to request
message that correspond to the ANET interface over which the ND de-registration.
message is sent, and set to '0' in all other aero options.
o R (the "Release" bit) is set to '1' in the aero option of an RS o Reserved is set to the value '0' on transmission.
message sent for the purpose of withdrawing from the MS;
otherwise, set to '0'. The MS withdraws the MNP, then returns an
RA with Router Lifetime set to '0'.
o D (the "Disable" bit) is set to '1' in the aero option of an RS o Nonce is set to a (pseudo)-random 32-bit value selected by the MN,
message for each ifIndex that is to be disabled in the recipient's and used to correlate received confirmations.
neighbor cache entry; otherwise, set to '0'. If the message
contains multiple aero options the D value in each option is
consulted.
o Both 'Reserved' fields are set to the value '0' on transmission. o A list of N (ifIndex[i], P[i])-tuples are included as follows:
o ifIndex is set to a 16-bit integer value corresponding to a * ifIndex[i] [RFC2863] is set to a 16-bit integer value
specific underlying ANET interface as discussed in [RFC2863]. corresponding to a specific underlying ANET interface. The
Once the MN has assigned an ifIndex to an ANET interface, the first ifIndex MUST correspond to the ANET interface over which
assignment MUST remain unchanged until the MN disables the the message is sent. Once the MN has assigned an ifIndex to an
interface. MNs MUST number each ifIndex with a value between '1' ANET interface, the assignment MUST remain unchanged until the
and '0xffff', and RA messages sent by the MS MUST set ifIndex to MN disables the interface. MNs MUST number each ifIndex with a
0. value between '1' and '0xffff'.
o P(i) is a set of Preferences that correspond to the 64 * P[i] is a per-ifIndex set of Preferences that correspond to the
Differentiated Service Code Point (DSCP) values [RFC2474]. Each 64 Differentiated Service Code Point (DSCP) values [RFC2474]
P(i) is set to the value '0' ("disabled"), '1' ("low"), '2' pertaining to the ANET interface. Each (P00 - P63) field is
("medium") or '3' ("high") to indicate a QoS preference level for set to the value '0' ("disabled"), '1' ("low"), '2' ("medium")
ANET interface selection purposes. or '3' ("high") to indicate a QoS preference level for ANET
interface selection purposes.
MNs such as aircraft typically have many wireless data link types The MS sends corresponding RA messages with AR options formatted as
(e.g. satellite-based, cellular, terrestrial, air-to-air directional, shown in Figure 3:
etc.) with diverse performance, cost and availability properties.
From the perspective of ND, the aero interface would therefore appear
to have multiple link layer addresses. In that case, ND messages MAY
include multiple aero options - each with an ifIndex that corresponds
to a specific ANET interface.
When an ND message includes aero options, the options corresponding 0 1 2 3
to the underlying ANET interface used to transmit the message MUST 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
set S to '1'. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length = 2 | Prefix Length |R| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Nonce |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Aero Registration (AR) Option Format in RA messages
In this format:
o Type is set to TBD.
o Length is set to the constant value '2' (i.e., 2 units of 8
octets).
o Prefix Length is set to the length included in the AR option of
the RS message that triggered the RA response.
o R is set to '1' to confirm registration or set to '0' to release/
decline registration.
o Reserved is set to the value '0' on transmission.
o Nonce echoes the 32 bit value received in the AR option of the
corresponding RS message.
o Prefix Lifetime is set to the time in seconds that the MSE will
maintain the Prefix registration.
9. Address Mapping - Multicast 9. Address Mapping - Multicast
The multicast address mapping of the native underlying ANET interface The multicast address mapping of the native underlying ANET interface
applies, and the ANET interacts with the MS for multicast forwarding applies. The mobile router on board the aircraft also serves as an
and group management purposes. IGMP/MLD Proxy for its EUNs and/or hosted applications per [RFC4605]
while using the link layer address of the router as the link layer
address for all multicast packets.
The mobile router on board the aircraft also serves as an IGMP/MLD 10. Address Mapping for IPv6 Neighbor Discovery Messages
Proxy for its EUNs and/or hosted applications per [RFC4605] while
using the link layer address of the router as the link layer address
for all multicast packets.
10. Conceptual Sending Algorithm As discussed in [RFC4861], IPv6 ND messages may be sent to either a
multicast or unicast link-scoped IPv6 destination address. For aero
interfaces in the MS-enabled model, however, IPv6 ND messaging must
be coordinated between the MN and MS only without invoking other
nodes on the ANET.
For this reason, each ANET link type is required to reserve a fixed
unicast link-layer address ("MSADDR") for the purpose of supporting
MN/MS IPv6 ND messaging the same as in [RFC6543]. For Ethernet-
compatible ANETs, this specification reserves one Ethernet unicast
address 00-00-5E-00-52-14. For non-Ethernet ANETs, MSADDR is
reserved per the assigned numbers authority for the ANET addressing
space.
MNs operating according to the MS-enabled model map all IPv6 ND
messages they send (i.e., both multicast and unicast) to MSADDR
instead of to an ordinary unicast or multicast link-layer address.
In this way, all of the MN's IPv6 ND messages will be received by MS
devices that are configured to accept packets destined to MSADDR
(i.e., a point-to-point neighbor model). Note that multiple MS
devices on the link could be configured to accept packets destinted
to MSADDR. Though out of scope for this document, such an
arrangement could provide basis for virtual router redundancy.
Therefore, ANET MS devices MUST accept and process packets destined
to MSADDR, while all other devices MUST NOT process packets destined
to MSADDR. In this arrangement MNs operating according to the MS-
enabled model have assurance that their IPv6 ND messages will be
handled only by the MS, and will not corrupt the neighbor caches of
classic devices and/or MNs on the link. This model has a well-
established operational experience in Proxy Mobile IPv6 (PMIP)
[RFC5213].
11. Conceptual Sending Algorithm
The MN's IPv6 layer selects the outbound aero interface according to The MN's IPv6 layer selects the outbound aero interface according to
standard IPv6 requirements. The aero interface maintains a default standard IPv6 requirements. The aero interface maintains default
route and a neighbor cache entry for MS endpoints, and may also routes and neighbor cache entries for MSEs, and may also include
include additional neighbor cache entries created through other means additional neighbor cache entries created through other means (e.g.,
(e.g., Address Resolution, static configuration, etc.). Address Resolution, static configuration, etc.).
When the MN sends packets via a MS endpoint, it may receive a When the MN sends packets, it may receive a Redirect message the same
Redirect message the same as for any IPv6 interface. When the MN as for any IPv6 interface. When the MN uses Address Resolution, the
uses Address Resolution, the aero interface forwards NS messages to aero interface forwards NS messages to an MSE (see: Section 12) which
an MS endpoint (see: Section 11) which acts as a link-layer acts as a link-layer forwarding agent according to the NBMA link
forwarding agent according to the NBMA link model. The resulting NA model. The resulting NA message will provide link-layer address
message will provide link-layer address information for the neighbor. information for the neighbor. When Neighbor Unreachability Detection
When Neighbor Unreachability Detection is used, the NS/NA exchange is used, the NS/NA exchange confirms reachability the same as for any
confirms reachability the same as for any IPv6 interface. IPv6 interface.
After a packet enters the aero interface, an outbound ANET interface After a packet enters the aero interface, an outbound ANET interface
is selected based on traffic engineering information such as DSCP, is selected based on traffic engineering information such as DSCP,
application port number, cost, performance, etc. Aero interface application port number, cost, performance, etc. Aero interface
traffic engineering could also be configured to perform replication traffic engineering could also be configured to perform replication
across multiple ANET interfaces for increased reliability at the across multiple ANET interfaces for increased reliability at the
expense of packet duplication. expense of packet duplication.
When a target neighbor has multiple link-layer addresses (each with a When a target neighbor has multiple link-layer addresses (each with a
different traffic engineering profile), the aero interface selects different traffic engineering profile), the aero interface selects
ANET interfaces and neighbor link-layer addresses according to both ANET interfaces and neighbor link-layer addresses according to both
its own outbound preferences and the inbound preferences of the its own outbound preferences and the inbound preferences of the
target neighbor. target neighbor.
10.1. Multiple Aero Interfaces 11.1. Multiple Aero Interfaces
MNs may associate with multiple MS instances concurrently. Each MS MNs may associate with multiple MS instances concurrently. Each MS
instance represents a distinct aero link distinguished by its instance represents a distinct aero link distinguished by its
associated MSPs. The MN configures a separate aero interface for associated MSPs. The MN configures a separate aero interface for
each link so that multiple interfaces (e.g., aero0, aero1, aero2, each link so that multiple interfaces (e.g., aero0, aero1, aero2,
etc.) are exposed to the IPv6 layer. etc.) are exposed to the IPv6 layer.
Depending on local policy and configuration, an MN may choose between Depending on local policy and configuration, an MN may choose between
alternative active aero interfaces using a packet's DSCP, routing alternative active aero interfaces using a packet's DSCP, routing
information or static configuration. In particular, the MN can add information or static configuration. In particular, the MN can add
the MSPs received in Prefix Information Options (PIOs) [RFC4861] the MSPs received in Prefix Information Options (PIOs) [RFC4861]
[RFC8028] as guidance for aero interface selection based on per- [RFC8028] as guidance for aero interface selection based on per-
packet source addresses . packet source addresses.
Each aero interface can be configured over the same or different sets Each aero interface can be configured over the same or different sets
of ANET interfaces. Each ANET distinguishes between the different of ANET interfaces. Each ANET distinguishes between the different
aero links based on the MSPs represented in per-packet IPv6 aero links based on the MSPs represented in per-packet IPv6
addresses. addresses.
Multiple distinct aero links can therefore be used to support fault Multiple distinct aero links can therefore be used to support fault
tolerance, load balancing, reliability, etc. The architectural model tolerance, load balancing, reliability, etc. The architectural model
parallels Layer 2 Virtual Local Area Networks (VLANs), where the MSPs parallels Layer 2 Virtual Local Area Networks (VLANs), where the MSPs
serve as (virtual) VLAN tags. serve as (virtual) VLAN tags.
11. Router and Prefix Discovery 12. Router Discovery and Prefix Assertion
MNs interact with the MS through mobility extensions on first-hop ANET access routers accept packets destined to the link-local Subnet
ANET Access Routers (ARs). MS extensions on ARs MUST examine the RS Router Anycast Address (fe80::). ANET access routers that support
messages received on an ANET interface. If the RS message includes the classic link model configure link-local addresses that are
aero options, the MS is invoked and an appropriate RA message is guaranteed not to conflict with MN link-local addresses as discussed
generated the same as for an IPv6 router. If the RS message does not in Section 7. ANET access routers that support the MS-enabled model
include aero options, the AR instead processes the RS message locally configure the link-layer address MSADDR (see: Section 10) and act as
the same as for an ordinary IPv6 link. proxies for all MSEs from the range fe80::1 through fe80::ffff:fffe.
MNs that support the classic model perform ordinary RS/RA exchanges
over each ANET the same as for ordinary IPv6 links. ANET access
routers send RAs with an IPv6 link-local source address from the
range fe80::1 through fe80::ffff:fffe that is guaranteed not to
conflict with the MN's aero address nor the address of any other
routers on the link. The MNs are then responsible for coordinating
their ANET interfaces on their own behalf and for coordinating with
any INET-based mobility agents. No further support from the ANET is
needed.
MNs that support the MS-enabled model instead interface with the MS
via RS/RA message exchanges that include AR options. For each ANET
interface, the MN sends initial RS messages with AR options with
link-layer address set to MSADDR and with network-layer address set
to a specific MSE address (or to fe80::ffff:ffff to request the ANET
to select an MSE). The ANET access router receives the RS messages
and contacts the corresponding MSE. When the MSE responds, the ANET
access router returns RA messages with AR options and with any
information for the link that would normally be delivered in a
solicited RA message.
MNs configure aero interfaces that observe the properties discussed MNs configure aero interfaces that observe the properties discussed
in the previous section. The aero interface and its underlying in the previous section. The aero interface and its underlying
interfaces are said to be in either the "UP" or "DOWN" state interfaces are said to be in either the "UP" or "DOWN" state
according to administrative actions in conjunction with the interface according to administrative actions in conjunction with the interface
connectivity status. An aero interface transitions to UP or DOWN connectivity status. An aero interface transitions to UP or DOWN
through administrative action and/or through state transitions of the through administrative action and/or through state transitions of the
underlying interfaces. When a first underlying interface transitions underlying interfaces. When a first underlying interface transitions
to UP, the aero interface also transitions to UP. When all to UP, the aero interface also transitions to UP. When all
underlying interfaces transition to DOWN, the aero interface also underlying interfaces transition to DOWN, the aero interface also
transitions to DOWN. transitions to DOWN.
MNs coordinate with the MS through RS/RA exchanges via their aero When an aero interface transitions to UP, the MN sends initial RS
interfaces. When an aero interface transitions to UP, the MN sends messages to register its MNP and an initial set of underlying ANET
initial RS messages with aero options to assert its MNP and register interfaces that are also UP. The MN sends additional RS messages to
an initial set of underlying ANET interfaces that are also UP. The refresh lifetimes and to register/deregister underlying ANET
MN sends additional RS messages to refresh MNP and/or router interfaces as they transition to UP or DOWN.
lifetimes, and to register/deregister underlying ANET interfaces as
they transition to UP or DOWN.
The MS sends RA messages with configuration information in response MS-enabled ANET access routers send RA messages with configuration
to a MN's RS message. The RA includes an aero option with ifIndex information in response to a MN's RS messages. The RA includes a
set to 0, a Router Lifetime value and PIOs with (A; L=0) that include Router Lifetime value and PIOs with (A; L=0) that include MSPs for
MSPs for the link. The configuration information may also include the link. The configuration information may also include Route
Route Information Options (RIO) options [RFC4191] with more-specific Information Options (RIO) options [RFC4191] with more-specific
routes, and an MTU option that specifies the maximum acceptable routes, and an MTU option that specifies the maximum acceptable
packet size for the link. The MS sends immediate unicast RA packet size for the link. The ANET access router sends immediate
responses without delay; therefore, the 'MAX_RA_DELAY_TIME' and unicast RA responses without delay; therefore, the
'MIN_DELAY_BETWEEN_RAS' constants for multicast RAs do not apply. 'MAX_RA_DELAY_TIME' and 'MIN_DELAY_BETWEEN_RAS' constants for
The MS MAY send periodic and/or event-driven unsolicited RA messages, multicast RAs do not apply. The ANET access router MAY send periodic
but is not required to do so for unicast advertisements [RFC4861]. and/or event-driven unsolicited RA messages, but is not required to
do so for unicast advertisements [RFC4861].
The MN sends RS messages from within the aero interface while using The MN sends RS messages from within the aero interface while using
an UP underlying ANET interface as the outbound interface. Each an UP underlying ANET interface as the outbound interface. Each RS
message is formatted as an ordinary RS message as though it message is formatted as though it originated from the IPv6 layer, but
originated from the IPv6 layer, but the process is coordinated wholly the process is coordinated wholly from within the aero interface and
from within the aero interface and is therefore opaque to the IPv6 is therefore opaque to the IPv6 layer. The MN sends initial RS
layer. The MN sends an initial RS message over an UP underlying messages over an UP underlying interface with its aero address as the
interface with its base aero address as the source address, all- source and the address of an MSE as the destination. The RS messages
routers multicast as the destination address and with an aero option include AR options with a valid Prefix Length as well as ifIndex and
with a valid Prefix Length and MNP. The aero option also sets S to 1 P(i) values appropriate for underlying ANET interfaces. The MS-
and contains valid ifIndex and P(i) values appropriate for the enabled ANET access router processes RS message and forwards the
underlying ANET interface. information in the AR option to the MSE.
When the MS receives the RS, it accepts the message if the prefix When the MSE processes the AR information, if the prefix registration
assertion was acceptable; otherwise, it drops the message silently. was accepted the MSE injects the MNP into the routing/mapping system
If the prefix assertion was accepted, the MS injects the MNP into the then caches the new Prefix Length, MNP, ifIndex and P(i) values. The
routing/mapping system then caches the new ifIndex, Prefix Length, MSE then returns a non-zero Prefix Lifetime if the prefix assertion
MNP and P(i) values. The MS then returns an RA with the aero address was acceptable; otherwise, with a zero Prefix Lifetime. The ANET
of an MS endpoint as the source address, the aero address of the MN access router then returns an RA message to the MN.
as the destination address, an aero option and with Router Lifetime
set to a non-zero value.
After the MN receives the initial RA confirming the MNP assertion, it When the MN receives the RA message, it creates a default route with
notes the aero address in the RA as the destination for all next hop address set to the MSE found in the RA source address and
subsequent RS messages it sends via this MS endpoint. If the MN with link-layer address set to MSADDR. The ANET access router will
needs to change to a different MS endpoint, it discovers and uses a then forward packets acting as a proxy between the MN and the actual
different MS aero address. MSE.
The MN then manages its underlying ANET interfaces according to their The MN then manages its underlying ANET interfaces according to their
states as follows: states as follows:
o When an underlying ANET interface transitions to UP, the MN sends o When an underlying ANET interface transitions to UP, the MN sends
an RS over the ANET interface with its base aero address as the an RS over the ANET interface with an AR option. The AR option
source address, the MS aero address as the destination address, contains a first ifIndex-tuple with values appropriate for this
and with one or more aero options. Aero options corresponding to ANET interface, and may contain additional ifIndex-tuples
the ANET interface set S to 1 and contain valid ifIndex and P(i)
values appropriate for this ANET interface, while any additional
aero options set S to 0 and contain valid ifIndex and P(i) values
appropriate for other ANET interfaces. appropriate for other ANET interfaces.
o When an underlying ANET interface transitions to DOWN, the MN o When an underlying ANET interface transitions to DOWN, the MN
sends an RS over any UP ANET interface with an aero option for the sends an RS/uNA message over any UP ANET interface with an AR
DOWN ANET interface with D set to 1. The RS may include option containing an ifIndex-tuple for the DOWN ANET interface
additional aero options for additional ANET interfaces as above. with all P(i) values set to '0'. The MN sends an RS when an
acknowledgement is required, or an uNA when reliability is not
thought to be a concern (e.g., if redundant transmissions are sent
on multiple ANET interfaces).
o When a MN wishes to release from the current MS endpoint, it sends o When a MN wishes to release from the current MSE, it sends an RS
an RS message over any UP ANET interface with an aero option with message over any UP ANET interface with an AR option with R set to
R set to 1. When the MS receives the RS message, it withdraws the 0. The corresponding MSE then withdraws the MNP from the routing/
MNP from the routing/mapping system and returns an RA message with mapping system and returns an RA message with an AR option with
Router Lifetime set to 0. Prefix Lifetime set to 0.
o When all of a MNs underlying interfaces have transitioned to DOWN, o When all of a MNs underlying interfaces have transitioned to DOWN,
the MS withdraws the MNP the same as if it had received an RS with the MSE withdraws the MNP the same as if it had received a message
an aero option with R set to 1. with an AR option with R set to 0.
The MN is responsible for retrying each RS/RA exchange up to The MN is responsible for retrying each RS exchange up to
MAX_RTR_SOLICITATIONS times separated by RTR_SOLICITATION_INTERVAL MAX_RTR_SOLICITATIONS times separated by RTR_SOLICITATION_INTERVAL
seconds until an RA is received. If no RA is received over multiple seconds until an RA is received. If no RA is received over multiple
UP ANET interfaces, the MN declares this MS endpoint unreachable and UP ANET interfaces, the MN declares this MSE unreachable and tries a
tries a different MS endpoint. different MSE.
The IPv6 layer sees the aero interface as an ordinary IPv6 interface. The IPv6 layer sees the aero interface as an ordinary IPv6 interface.
Therefore, when the IPv6 layer sends an RS message the aero interface Therefore, when the IPv6 layer sends an RS message the aero interface
returns an internally-generated RA message as though the message returns an internally-generated RA message as though the message
originated from an IPv6 router. The internally-generated RA message originated from an IPv6 router. The internally-generated RA message
contains configuration information (such as Router Lifetime, MTU, contains configuration information (such as Router Lifetime, MTU,
etc.) that is consistent with the information received from the RAs etc.) that is consistent with the information received from the RAs
generated by the MS. generated by the MS.
Whether the aero interface RS/RA process is initiated from the Whether the aero interface IPv6 ND messaging process is initiated
receipt of an RS message from the IPv6 layer is an implementation from the receipt of an RS message from the IPv6 layer is an
matter. Some implementations may elect to defer the RS/RA process implementation matter. Some implementations may elect to defer the
until an RS is received from the IPv6 layer, while others may elect IPv6 ND messaging process until an RS is received from the IPv6
to initiate the RS/RA process independently of any IPv6 layer layer, while others may elect to initiate the process independently
messaging. of any IPv6 layer messaging.
12. IANA Considerations 13. IANA Considerations
The IANA is instructed to allocate an IPv6 Neighbor Discovery option The IANA is instructed to allocate an official number from the IPv6
type for the aero option in the IPv6 Neighbor Discovery Option Neighbor Discovery Option Formats registry for the Aero Registration
Formats registry. (TBD) option. Implementations set TBD to 253 as an interim value
[RFC4727].
13. Security Considerations The IANA is instructed to allocate one Ethernet unicast address,
00-00-5E-00-52-14 [RFC5214] in the registry "IANA Ethernet Address
Block - Unicast Use".
14. Security Considerations
Security considerations are the same as defined for the specific Security considerations are the same as defined for the specific
access network interface types, and readers are referred to the access network interface types, and readers are referred to the
appropriate interface specifications. appropriate interface specifications.
IPv6 and IPv6 ND security considerations also apply, and are IPv6 and IPv6 ND security considerations also apply, and are
specified in the normative references. specified in the normative references.
14. Acknowledgements 15. Acknowledgements
This document was prepared per the consensus decision at the 8th This document was prepared per the consensus decision at the 8th
Conference of the International Civil Aviation Organization (ICAO) Conference of the International Civil Aviation Organization (ICAO)
Working Group-I Mobility Subgroup on March 22, 2019. Attendees and Working Group-I Mobility Subgroup on March 22, 2019. Attendees and
contributors included: Guray Acar, Danny Bharj, Francois D'Humieres, contributors included: Guray Acar, Danny Bharj, Francois D'Humieres,
Pavel Drasil, Nikos Fistas, Giovanni Garofolo, Vaughn Maiolla, Tom Pavel Drasil, Nikos Fistas, Giovanni Garofolo, Vaughn Maiolla, Tom
McParland, Victor Moreno, Madhu Niraula, Brent Phillips, Liviu McParland, Victor Moreno, Madhu Niraula, Brent Phillips, Liviu
Popescu, Jacky Pouzet, Aloke Roy, Greg Saccone, Robert Segers, Popescu, Jacky Pouzet, Aloke Roy, Greg Saccone, Robert Segers,
Stephane Tamalet, Fred Templin, Bela Varkonyi, Tony Whyman, and Stephane Tamalet, Fred Templin, Bela Varkonyi, Tony Whyman, and
Dongsong Zeng. Dongsong Zeng.
The following individuals are acknowledged for their useful comments: The following individuals are acknowledged for their useful comments:
Pavel Drasil, Zdenek Jaron. Pavel Drasil, Zdenek Jaron, Madhu Niraula.
. .
15. References 16. References
15.1. Normative References 16.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS "Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474, Field) in the IPv4 and IPv6 Headers", RFC 2474,
DOI 10.17487/RFC2474, December 1998, DOI 10.17487/RFC2474, December 1998,
<https://www.rfc-editor.org/info/rfc2474>. <https://www.rfc-editor.org/info/rfc2474>.
[RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and [RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and
More-Specific Routes", RFC 4191, DOI 10.17487/RFC4191, More-Specific Routes", RFC 4191, DOI 10.17487/RFC4191,
November 2005, <https://www.rfc-editor.org/info/rfc4191>. November 2005, <https://www.rfc-editor.org/info/rfc4191>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <https://www.rfc-editor.org/info/rfc4291>. 2006, <https://www.rfc-editor.org/info/rfc4291>.
[RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4,
ICMPv6, UDP, and TCP Headers", RFC 4727,
DOI 10.17487/RFC4727, November 2006,
<https://www.rfc-editor.org/info/rfc4727>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007, DOI 10.17487/RFC4861, September 2007,
<https://www.rfc-editor.org/info/rfc4861>. <https://www.rfc-editor.org/info/rfc4861>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862, Address Autoconfiguration", RFC 4862,
DOI 10.17487/RFC4862, September 2007, DOI 10.17487/RFC4862, September 2007,
<https://www.rfc-editor.org/info/rfc4862>. <https://www.rfc-editor.org/info/rfc4862>.
[RFC8028] Baker, F. and B. Carpenter, "First-Hop Router Selection by [RFC8028] Baker, F. and B. Carpenter, "First-Hop Router Selection by
Hosts in a Multi-Prefix Network", RFC 8028, Hosts in a Multi-Prefix Network", RFC 8028,
DOI 10.17487/RFC8028, November 2016, DOI 10.17487/RFC8028, November 2016,
<https://www.rfc-editor.org/info/rfc8028>. <https://www.rfc-editor.org/info/rfc8028>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200, (IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017, DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>. <https://www.rfc-editor.org/info/rfc8200>.
15.2. Informative References 16.2. Informative References
[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet
Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998,
<https://www.rfc-editor.org/info/rfc2464>. <https://www.rfc-editor.org/info/rfc2464>.
[RFC2473] Conta, A. and S. Deering, "Generic Packet Tunneling in [RFC2473] Conta, A. and S. Deering, "Generic Packet Tunneling in
IPv6 Specification", RFC 2473, DOI 10.17487/RFC2473, IPv6 Specification", RFC 2473, DOI 10.17487/RFC2473,
December 1998, <https://www.rfc-editor.org/info/rfc2473>. December 1998, <https://www.rfc-editor.org/info/rfc2473>.
[RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group [RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group
MIB", RFC 2863, DOI 10.17487/RFC2863, June 2000, MIB", RFC 2863, DOI 10.17487/RFC2863, June 2000,
<https://www.rfc-editor.org/info/rfc2863>. <https://www.rfc-editor.org/info/rfc2863>.
[RFC4605] Fenner, B., He, H., Haberman, B., and H. Sandick, [RFC4605] Fenner, B., He, H., Haberman, B., and H. Sandick,
"Internet Group Management Protocol (IGMP) / Multicast "Internet Group Management Protocol (IGMP) / Multicast
Listener Discovery (MLD)-Based Multicast Forwarding Listener Discovery (MLD)-Based Multicast Forwarding
("IGMP/MLD Proxying")", RFC 4605, DOI 10.17487/RFC4605, ("IGMP/MLD Proxying")", RFC 4605, DOI 10.17487/RFC4605,
August 2006, <https://www.rfc-editor.org/info/rfc4605>. August 2006, <https://www.rfc-editor.org/info/rfc4605>.
[RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
RFC 5213, DOI 10.17487/RFC5213, August 2008,
<https://www.rfc-editor.org/info/rfc5213>.
[RFC5214] Templin, F., Gleeson, T., and D. Thaler, "Intra-Site
Automatic Tunnel Addressing Protocol (ISATAP)", RFC 5214,
DOI 10.17487/RFC5214, March 2008,
<https://www.rfc-editor.org/info/rfc5214>.
[RFC6543] Gundavelli, S., "Reserved IPv6 Interface Identifier for
Proxy Mobile IPv6", RFC 6543, DOI 10.17487/RFC6543, May
2012, <https://www.rfc-editor.org/info/rfc6543>.
[RFC7084] Singh, H., Beebee, W., Donley, C., and B. Stark, "Basic [RFC7084] Singh, H., Beebee, W., Donley, C., and B. Stark, "Basic
Requirements for IPv6 Customer Edge Routers", RFC 7084, Requirements for IPv6 Customer Edge Routers", RFC 7084,
DOI 10.17487/RFC7084, November 2013, DOI 10.17487/RFC7084, November 2013,
<https://www.rfc-editor.org/info/rfc7084>. <https://www.rfc-editor.org/info/rfc7084>.
[RFC7421] Carpenter, B., Ed., Chown, T., Gont, F., Jiang, S., [RFC7421] Carpenter, B., Ed., Chown, T., Gont, F., Jiang, S.,
Petrescu, A., and A. Yourtchenko, "Analysis of the 64-bit Petrescu, A., and A. Yourtchenko, "Analysis of the 64-bit
Boundary in IPv6 Addressing", RFC 7421, Boundary in IPv6 Addressing", RFC 7421,
DOI 10.17487/RFC7421, January 2015, DOI 10.17487/RFC7421, January 2015,
<https://www.rfc-editor.org/info/rfc7421>. <https://www.rfc-editor.org/info/rfc7421>.
skipping to change at page 16, line 7 skipping to change at page 19, line 31
Length value larger than 3. Length value larger than 3.
For example, adaptation of the aero interface to the Aeronautical For example, adaptation of the aero interface to the Aeronautical
Telecommunications Network with Internet Protocol Services (ATN/IPS) Telecommunications Network with Internet Protocol Services (ATN/IPS)
includes link selection preferences based on transport port numbers includes link selection preferences based on transport port numbers
in addition to the existing DSCP-based preferences. ATN/IPS nodes in addition to the existing DSCP-based preferences. ATN/IPS nodes
maintain a map of transport port numbers to 64 possible preference maintain a map of transport port numbers to 64 possible preference
fields, e.g., TCP port 22 maps to preference field 8, TCP port 443 fields, e.g., TCP port 22 maps to preference field 8, TCP port 443
maps to preference field 20, UDP port 8060 maps to preference field maps to preference field 20, UDP port 8060 maps to preference field
34, etc. The extended aero option format for ATN/IPS is shown in 34, etc. The extended aero option format for ATN/IPS is shown in
Figure 3, where the Length value is 7 and the 'Q(i)' fields provide Figure 4, where the Length value is 7 and the 'Q(i)' fields provide
link preferences for the corresponding transport port number. link preferences for the corresponding transport port number.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length = 5 | Prefix Length |S|R|D| Reserved| | Type | Length = 5 | Prefix Length |S|R|D| Reserved|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ifIndex | Reserved | | ifIndex | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P00|P01|P02|P03|P04|P05|P06|P07|P08|P09|P10|P11|P12|P13|P14|P15| |P00|P01|P02|P03|P04|P05|P06|P07|P08|P09|P10|P11|P12|P13|P14|P15|
skipping to change at page 16, line 34 skipping to change at page 20, line 29
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Q00|Q01|Q02|Q03|Q04|Q05|Q06|Q07|Q08|Q09|Q10|Q11|Q12|Q13|Q14|Q15| |Q00|Q01|Q02|Q03|Q04|Q05|Q06|Q07|Q08|Q09|Q10|Q11|Q12|Q13|Q14|Q15|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Q16|Q17|Q18|Q19|Q20|Q21|Q22|Q23|Q24|Q25|Q26|Q27|Q28|Q29|Q30|Q31| |Q16|Q17|Q18|Q19|Q20|Q21|Q22|Q23|Q24|Q25|Q26|Q27|Q28|Q29|Q30|Q31|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Q32|Q33|Q34|Q35|Q36|Q37|Q38|Q39|Q40|Q41|Q42|Q43|Q44|Q45|Q46|Q47| |Q32|Q33|Q34|Q35|Q36|Q37|Q38|Q39|Q40|Q41|Q42|Q43|Q44|Q45|Q46|Q47|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Q48|Q49|Q50|Q51|Q52|Q53|Q54|Q55|Q56|Q57|Q58|Q59|Q60|Q61|Q62|Q63| |Q48|Q49|Q50|Q51|Q52|Q53|Q54|Q55|Q56|Q57|Q58|Q59|Q60|Q61|Q62|Q63|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: ATN/IPS Extended Aero Option Format Figure 4: ATN/IPS Extended Aero Option Format
Appendix B. Prefix Length Considerations Appendix B. Prefix Length Considerations
The IPv6 addressing architecture [RFC4291] reserves the prefix ::/8; The IPv6 addressing architecture [RFC4291] reserves the prefix ::/8;
this assures that MNPs will not begin with ::32 so that MN and MS this assures that MNPs will not begin with ::32 so that MN and MS
aero addresses cannot overlap. Additionally, this specification aero addresses cannot overlap. Additionally, this specification
currently observes the 64-bit boundary in IPv6 addresses [RFC7421]. currently observes the 64-bit boundary in IPv6 addresses [RFC7421].
MN aero addresses insert the most-significant 64 MNP bits into the MN aero addresses insert the most-significant 64 MNP bits into the
least-significant 64 bits of the prefix fe80::/64, however [RFC4291] least-significant 64 bits of the prefix fe80::/64, however [RFC4291]
defines the link-local prefix as fe80::/10 meaning "fe80" followed by defines the link-local prefix as fe80::/10 meaning "fe80" followed by
54 unused bits followed by the least-significant 64 bits of the 54 unused bits followed by the least-significant 64 bits of the
address. Future versions of this specification may adapt the 54 address. Future versions of this specification may adapt the 54
unused bits for extended coding of MNP prefixes of /65 or longer (up unused bits for extended coding of MNP prefixes of /65 or longer (up
to /118). to /118).
Appendix C. Change Log Appendix C. Change Log
<< RFC Editor - remove prior to publication >> << RFC Editor - remove prior to publication >>
Differences from draft-templin-atn-aero-interface-04 to draft-
templin-atn-aero-interface-05:
o Introduced RFC6543 precedent for focusing IPv6 ND messaging to a
reserved unicast link-layer address
o Introduced new IPv6 ND option for Aero Registration
o Specification of MN-to-MSE message exchanges via the ANET access
router as a proxy
o IANA Considerations updated to include registration requests and
set interim RFC4727 option type value.
Differences from draft-templin-atn-aero-interface-03 to draft- Differences from draft-templin-atn-aero-interface-03 to draft-
templin-atn-aero-interface-04: templin-atn-aero-interface-04:
o Removed MNP from aero option format - we already have RIOs and o Removed MNP from aero option format - we already have RIOs and
PIOs, and so do not need another option type to include a Prefix. PIOs, and so do not need another option type to include a Prefix.
o Clarified that the RA message response must include an aero option o Clarified that the RA message response must include an aero option
to indicate to the MN that the ANET provides a MS. to indicate to the MN that the ANET provides a MS.
o MTU interactions with link adaptation clarified. o MTU interactions with link adaptation clarified.
 End of changes. 68 change blocks. 
236 lines changed or deleted 407 lines changed or added

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