Internet DRAFT - draft-robles-roll-useofrplinfo
draft-robles-roll-useofrplinfo
ROLL Working Group M. Robles
Internet-Draft Ericsson
Intended status: Informational M. Richardson
Expires: April 21, 2016 SSW
P. Thubert
Cisco
October 19, 2015
When to use RFC 6553, 6554 and IPv6-in-IPv6
draft-robles-roll-useofrplinfo-02
Abstract
This document states different cases where RFC 6553, RFC 6554 and
IPv6-in-IPv6 encapsulation is required to set the bases to help
defining the compression of RPL routing information in LLN
environments.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on April 21, 2016.
Copyright Notice
Copyright (c) 2015 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
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include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology and Requirements Language . . . . . . . . . . . . 3
3. Sample/reference topology . . . . . . . . . . . . . . . . . . 3
4. Use cases . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. Storing mode . . . . . . . . . . . . . . . . . . . . . . . . 8
5.1. Example of Flow from RPL-aware-leaf to root . . . . . . . 8
5.2. Example of Flow from root to RPL-aware-leaf . . . . . . . 9
5.3. Example of Flow from root to not-RPL-aware-leaf . . . . . 10
5.4. Example of Flow from not-RPL-aware-leaf to root . . . . . 10
5.5. Example of Flow from RPL-aware-leaf to Internet . . . . . 11
5.6. Example of Flow from Internet to RPL-aware-leaf . . . . . 11
5.7. Example of Flow from not-RPL-aware-leaf to Internet . . . 12
5.8. Example of Flow from Internet to not-RPL-aware-leaf . . . 13
5.9. Example of Flow from RPL-aware-leaf to RPL-aware-leaf . . 14
5.10. Example of Flow from RPL-aware-leaf to non-RPL-aware-leaf 15
5.11. Example of Flow from not-RPL-aware-leaf to RPL-aware-leaf 16
5.12. Example of Flow from not-RPL-aware-leaf to not-RPL-aware-
leaf . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6. Non Storing mode . . . . . . . . . . . . . . . . . . . . . . 18
6.1. Example of Flow from RPL-aware-leaf to root . . . . . . . 18
6.2. Example of Flow from root to RPL-aware-leaf . . . . . . . 19
6.3. Example of Flow from root to not-RPL-aware-leaf . . . . . 19
6.4. Example of Flow from not-RPL-aware-leaf to root . . . . . 20
6.5. Example of Flow from RPL-aware-leaf to Internet . . . . . 20
6.6. Example of Flow from Internet to RPL-aware-leaf . . . . . 21
6.7. Example of Flow from not-RPL-aware-leaf to Internet . . . 22
6.8. Example of Flow from Internet to not-RPL-aware-leaf . . . 23
6.9. Example of Flow from RPL-aware-leaf to RPL-aware-leaf . . 24
6.10. Example of Flow from RPL-aware-leaf to not-RPL-aware-leaf 25
6.11. Example of Flow from not-RPL-aware-leaf to RPL-aware-leaf 26
6.12. Example of Flow from not-RPL-aware-leaf to not-RPL-aware-
leaf . . . . . . . . . . . . . . . . . . . . . . . . . . 26
7. Future RPL work . . . . . . . . . . . . . . . . . . . . . . . 27
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
9. Security Considerations . . . . . . . . . . . . . . . . . . . 27
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 28
11.1. Normative References . . . . . . . . . . . . . . . . . . 28
11.2. Informative References . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29
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1. Introduction
RPL [RFC6550] is a routing protocol for constrained networks. RFC
6553 [RFC6553] defines the "RPL option", carried within the IPv6 Hop-
by-Hop header to quickly identify inconsistencies in the routing
topology. RFC 6554 [RFC6554] defines the "RPL Source Route Header",
an IPv6 Extension Header to deliver datagrams within a RPL routing
domain.
Several discussions in the ROLL/6lo/6TiSCH Mailing Lists took place
focusing in the definition of how to compress RPL Information in
constrained environment. ROLL Virtual Interim Meeting (02-2015)
concluded that there is a need to define how to use [RFC6553],
[RFC6554] and IPv6-in-IPv6 encapsulation to be able to set the
correct environment for compression. A Routing Header Dispatch for
6LoWPAN (6LoRH) [I-D.thubert-6lo-routing-dispatch] defines a method
to compress RPL Option information and Routing Header type 3
(RFC6554) and an efficient IP-in-IP technique.
This document is going to be focused in data plane messages and how
can be transmitted within the above mentioned RFCs.
2. Terminology and Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Terminology defined in [RFC7102]
3. Sample/reference topology
A RPL network is composed of a 6LBR (6LoWPAN Border Router), Backbone
Router (6BBR), 6LR (6LoWPAN Router) and 6LN (6LoWPAN Node) as leaf
logically organized in a DODAG structure (Destination Oriented
Directed Acyclic Graph).
RPL defines the RPL Control messages (control plane ), a new ICMPv6
message with Type 155. DIS, DIO and DAO messages are all RPL Control
messages but with different Code values.
RPL supports two modes of Downward traffic: in storing mode, it is
fully stateful or an in non-storing, it is fully source routed. A
RPL Instance is either fully storing or fully non-storing, i.e. a RPL
Instance with a combination of storing and non-storing nodes is not
supported with the current specifications.
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+--------------+
| Upper Layers |
| |
+--------------+
| RPL |
| |
+--------------+
| ICMPv6 |
| |
+--------------+
| IPv6 |
| |
+--------------+
| 6LoWPAN |
| |
+--------------+
| PHY-MAC |
| |
+--------------+
Figure 1: RPL Stack.
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+---------+
+---+Internet |
| +---------+
|
+----+--+
|DODAG |
+---------+Root +----------+
| |6LBR | |
| +----+--+ |
| | |
| | |
... ... ...
| | |
+-----+-+ +--+---+ +--+---+
|6LR | | | | |
+-----+ | | | | |
| | | | | | +------+
| +-----+-+ +-+----+ +-+----+ |
| | | | |
| | | | |
| | | | |
+-+---+ +-+---+ +--+--+ +- --+ +---+-+
|Leaf | | | | | | | | |
|6LN | | | | | | | | |
+-----+ +-----+ +-----+ +----+ +-----+
Figure 2: A reference RPL Topology.
This document is in part motivated by the work that is ongoing at the
6TiSCH working group. The 6TiSCH architecture
[I-D.ietf-6tisch-architecture] draft explains the network
architecture of a 6TiSCH network. This architecture is used for the
remainder of this document.
The scope of the 6TiSCH Architecture is a Backbone Link that
federates multiple LLNs (mesh) as a single IPv6 Multi-Link Subnet.
Each LLN in the subnet is anchored at a Backbone Router (6BBR). The
Backbone Routers interconnect the LLNs over the Backbone Link and
emulate that the LLN nodes are present on the Backbone thus creating
a so-called: Multi-Link Subnet. An LLN node can move freely from an
LLN anchored at a Backbone Router to another LLN anchored at the same
or a different Backbone Router inside the Multi-Link Subnet and
conserve its addresses.
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|
+-----+
| | Border Router to the RPL domain
| | (may be a RPL virtual root)
+-----+
|
| Backbone
+-------------------+-------------------+
| | |
+-----+ +-----+ +-----+
| | Backbone | | Backbone | | Backbone
| | router | | router | | router
+|---|+ +-|||-+ +-[_]-+
| | PCI-exp / | \ USB | Ethernet
( ) ( ) ( )( )( ) (6LBR == RPL DODAG root)
o o o o o o o o o o o o
o o o o o o o o o o o o o o o o
o o o o o o o o o o 6LR == RPL router) o o
o o o o o o o z
o o o o o o (6LoWPAN Host)
<----------------------- RPL Instance ------------------------>
Figure 3: RPL domain architecture
4. Use cases
In data plane context a combination of RFC6553, RFC6554 and IPv6-in-
IPv6 encapsulation is going to be analyzed for the following traffic
flows:
-Flow from RPL-aware-leaf to root
-Flow from root to RPL-aware-leaf
-Flow from not-RPL-aware-leaf to root
-Flow from root to not-RPL-aware-leaf
-Flow from RPL-aware-leaf to Internet
-Flow from Internet to RPL-aware-leaf
-Flow from not-RPL-aware-leaf to Internet
-Flow from Internet to not-RPL-aware-leaf
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-Flow from RPL-aware-leaf to RPL-aware-leaf
-Flow from RPL-aware-leaf to not-RPL-aware-leaf
-Flow from not-RPL-aware-leaf to RPL-aware-leaf
-Flow from not-RPL-aware-leaf to not-RPL-aware-leaf
This document assumes a rule that a Header cannot be inserted or
removed on the fly inside an IPv6 packet that is being routed.
- This means that an intermediate router that needs to add a header
must encapsulate the packet in an outer IP header where the new
header can be placed.
- This also means that a Header can only be removed by an
intermediate router if it is placed in an encapsulating IPv6 Header,
and in that case, the whole encapsulating header must be removed - a
replacement may be added.
This document recognizes that some headers such as a Routing Header
or a Hop-by-Hop header may be modified by routers on the path of the
packet without the need to add to remove an encapsulating header.
The RPL RH and the RPL option are mutable but recoverable .
RPI should be present in every single RPL data packet. There is an
exception in non-storing mode, when a packet is going down from the
route: the entire route is written, so there are no loops of
confusion about which table to use (purpose of instanceID).
The applicability for storing (RPL-SN) and non-Storing (RPL-NSN)
modes for the previous cases is showed as follows:
+---------------+------+------+---------+--------+--------+---------+
| Use Case | RPL- | RPL- | RPL-SN | RPL- | RPL- | RPL-NSN |
| | SN | SN | IP-in- | NSN | NSN | IP-in- |
| | RPI | RH3 | IP | RPI | RH3 | IP |
| | (RFC | (RFC | | | | |
| | 6553 | 6554 | | | | |
| | ) | ) | | | | |
+---------------+------+------+---------+--------+--------+---------+
| RPL-aware- | Yes | No | No | Yes | No | No |
| leaf to root | | | | | | |
| root to RPL- | Yes | No | No | Yes | Yes | No |
| aware-leaf | | | | | | |
| not-RPL- | Yes | No | Yes | Yes | No | Yes |
| aware-leaf to | | | | | | |
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| root | | | | | | |
| root to not- | Yes | No | Yes | Yes | Yes | Yes |
| RPL-aware- | | | | | | |
| leaf | | | | | | |
| RPL-aware- | Yes | No | Yes | Yes | No | Yes |
| leaf to | | | | | | |
| Internet | | | | | | |
| Internet to | Yes | No | Yes | Yes | Yes | Yes |
| RPL-aware- | | | | | | |
| leaf | | | | | | |
| not-RPL- | Yes | No | Yes | Yes | No | Yes |
| aware-leaf to | | | | | | |
| Internet | | | | | | |
| Internet to | Yes | No | Yes | Yes | Yes | Yes |
| not-RPL- | | | | | | |
| aware-leaf | | | | | | |
| RPL-aware- | Yes | No | No | Yes | Yes | Yes |
| leaf to RPL- | | | | | | |
| aware-leaf | | | | | | |
| RPL-aware- | Yes | No | Yes | Yes | Yes | Yes |
| leaf to not- | | | | | | |
| RPL-aware- | | | | | | |
| leaf | | | | | | |
| not-RPL- | Yes | No | Yes | Yes | Yes | Yes |
| aware-leaf to | | | | | | |
| RPL-aware- | | | | | | |
| leaf | | | | | | |
| not-RPL- | Yes | No | Yes | Yes | Yes | Yes |
| aware-leaf to | | | | | | |
| not-RPL- | | | | | | |
| aware-leaf | | | | | | |
+---------------+------+------+---------+--------+--------+---------+
Table 1: Posibility to transmit in Storing or Non-Storing mode: RPI,
RH3, IP-in-IP encapsulation
5. Storing mode
5.1. Example of Flow from RPL-aware-leaf to root
As states in Section 16.2 of [RFC6550] a RPL-aware-leaf node does
not generally issue DIO messages, a leaf node accepts DIO messages
(In inconsistency a leaf node generates DIO with infinite rank, to
fix it). It may issue DAO and DIS messages though it generally
ignores DAO and DIS messages.
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In storing mode is suitable the use of RFC 6553 to send RPL
Information through HBH field checking the routing table to find out
where to send the message.
In this case the flow comprises:
RPL-aware-leaf (6LN) --> 6LR --> 6LR,... --> root (6LBR) Note: In
this document 6LRs, 6LBR are always full-fledge RPL routers
The 6LN inserts the RPI header, and send the packet to 6LR which
decrement the rank in RPI and send the packet up. When the packet
arrives to 6LBR, the RPI is removed and the packet is processed.
+-------------------+-----+------+------+
| Header | 6LN | 6LR | 6LBR |
+-------------------+-----+------+------+
| Inserted headers | RPI | -- | -- |
| Removed headers | -- | -- | RPI |
| Re-added headers | -- | -- | -- |
| Modified headers | -- | RPI | -- |
| Untouched headers | -- | -- | -- |
+-------------------+-----+------+------+
Storing: Summary of the use of headers from RPL-aware-leaf to root
5.2. Example of Flow from root to RPL-aware-leaf
In this case the flow comprises:
root (6LBR)--> 6LR --> RPL-aware-leaf (6LN)
In this case the 6LBR insert RPI header and send the packet down, the
6LR is going to increment the rank in RPI (examines instanceID for
multiple tables), the packet is processed in 6LN and RPI removed.
+-------------------+------+-------+------+
| Header | 6LBR | 6LR | 6LN |
+-------------------+------+-------+------+
| Inserted headers | RPI | -- | -- |
| Removed headers | -- | -- | RPI |
| Re-added headers | -- | -- | -- |
| Modified headers | -- | RPI | -- |
| Untouched headers | -- | -- | -- |
+-------------------+------+-------+------+
Storing: Summary of the use of headers from root to RPL-aware-leaf
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5.3. Example of Flow from root to not-RPL-aware-leaf
In this case the flow comprises:
root (6LBR)--> 6LR --> not-RPL-aware-leaf (6LN)
It includes IPv6-in-IPv6 encapsulation to transmit information not
related with the RPL domain. In the 6LBR the RPI header is inserted
into an IPv6-in-IPv6 header addressed to the last 6LR, which removes
the header before pass the packet to the IPv6 node.
+-------------------+-------------------+-------------------+------+
| Header | 6LBR | 6LR | IPv6 |
+-------------------+-------------------+-------------------+------+
| Inserted headers | IPv6-in-IPv6(RPI) | -- | -- |
| Removed headers | -- | IPv6-in-IPv6(RPI) | -- |
| Re-added headers | -- | -- | -- |
| Modified headers | -- | -- | -- |
| Untouched headers | -- | -- | -- |
+-------------------+-------------------+-------------------+------+
Storing: Summary of the use of headers from root to not-RPL-aware-
leaf
5.4. Example of Flow from not-RPL-aware-leaf to root
In this case the flow comprises:
not-RPL-aware-leaf (6LN) --> 6LR --> root (6LBR)
When the packet arrives from IPv6 node to 6LR. This router insert
the RPI encapsuladed in a IPv6-in-IPv6 header addressed to the root.
The root removes the header and process the packet
+-------------------+------+--------------------+-------------------+
| Header | IPv6 | 6LR | 6LBR |
+-------------------+------+--------------------+-------------------+
| Inserted headers | -- | IPv6-in-IPv6(RPI) | -- |
| Removed headers | -- | -- | IPv6-in-IPv6(RPI) |
| Re-added headers | -- | -- | -- |
| Modified headers | -- | -- | -- |
| Untouched headers | -- | -- | -- |
+-------------------+------+--------------------+-------------------+
Storing: Summary of the use of headers from not-RPL-aware-leaf to
root
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5.5. Example of Flow from RPL-aware-leaf to Internet
RPL information from RFC 6553 should not go out to Internet. The
router should take this information out before send the packet to
Internet. The HBH Option is going to be analyzed in each node to the
root.
In this case the flow comprises:
RPL-aware-leaf (6LN) --> 6LR --> root (6LBR) --> Internet
6LN insert RPI in a IPv6-in-IPv6 in a outer header, and send the
packet to 6LR, which modified the rank in the RPI. When the packet
arrives to 6LBR, the RPI is removed.
+----------+-------------------+-----+-------------------+----------+
| Header | 6LN | 6LR | 6LBR | Internet |
+----------+-------------------+-----+-------------------+----------+
| Inserted | IPv6-in-IPv6(RPI) | -- | -- | -- |
| headers | | | | |
| Removed | -- | -- | IPv6-in-IPv6(RPI) | -- |
| headers | | | | |
| Re-added | -- | -- | -- | -- |
| headers | | | | |
| Modified | -- | RPI | -- | -- |
| headers | | | | |
| Untouche | -- | -- | -- | -- |
| d | | | | |
| headers | | | | |
+----------+-------------------+-----+-------------------+----------+
Storing: Summary of the use of headers from RPL-aware-leaf to
Internet
5.6. Example of Flow from Internet to RPL-aware-leaf
In this case the flow comprises:
Internet --> root (6LBR) --> 6LR --> RPL-aware-leaf (6LN)
When the packet arrives from Internet to 6LBR the RPI header is added
in a outer IPv6-in-IPv6 header and send to 6LR, which modifies the
rank in the RPI. When the packet arrives 6LN the RPI header is
removed and the packet processed.
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+----------+----------+-------------------+-----+-------------------+
| Header | Internet | 6LBR | 6LR | 6LN |
+----------+----------+-------------------+-----+-------------------+
| Inserted | -- | IPv6-in-IPv6(RPI) | -- | -- |
| headers | | | | |
| Removed | -- | -- | -- | IPv6-in-IPv6(RPI) |
| headers | | | | |
| Re-added | -- | -- | -- | -- |
| headers | | | | |
| Modified | -- | -- | RPI | -- |
| headers | | | | |
| Untouche | -- | -- | -- | -- |
| d | | | | |
| headers | | | | |
+----------+----------+-------------------+-----+-------------------+
Storing: Summary of the use of headers from Internet to RPL-aware-
leaf
5.7. Example of Flow from not-RPL-aware-leaf to Internet
In this case the flow comprises:
not-RPL-aware-leaf (6LN) = IPv6 node --> 6LR --> root (6LBR) -->
Internet
In the IPv6 node the flow label is assumed to be zero, the packet is
transmited to 6LR which encapsule the RPI header in an outer IPv6-in-
IPv6 header and send to 6LBR, which removes this header and send the
packet to Internet and might set the flow label field.
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+----------+-----+-------------------+-------------------+----------+
| Header | IPv | 6LR | 6LBR | Internet |
| | 6 | | | |
+----------+-----+-------------------+-------------------+----------+
| Inserted | -- | IPv6-in-IPv6(RPI) | -- | -- |
| headers | | | | |
| Removed | -- | -- | IPv6-in-IPv6(RPI) | -- |
| headers | | | | |
| Re-added | -- | -- | -- | -- |
| headers | | | | |
| Modified | -- | -- | -- | -- |
| headers | | | | |
| Untouche | -- | -- | -- | -- |
| d | | | | |
| headers | | | | |
+----------+-----+-------------------+-------------------+----------+
Storing: Summary of the use of headers from not-RPL-aware-leaf to
Internet
5.8. Example of Flow from Internet to not-RPL-aware-leaf
In this case the flow comprises:
Internet --> root (6LBR) --> 6LR --> not-RPL-aware-leaf (6LN)
6LBR get the packet from Internet and add a RPI header encapsulated
in a IPv6-in-IPv6 header addressed to 6LR and send the packet down.
The flow label is set to zero on inner IP. The last 6LR removes the
RPI header. The IPv6 node might set the flow label since may arrive
with zero value.
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+----------+---------+-------------------+-------------------+------+
| Header | Interne | 6LBR | 6LR | IPv6 |
| | t | | | |
+----------+---------+-------------------+-------------------+------+
| Inserted | -- | IPv6-in-IPv6(RPI) | -- | -- |
| headers | | | | |
| Removed | -- | -- | IPv6-in-IPv6(RPI) | -- |
| headers | | | | |
| Re-added | -- | -- | -- | -- |
| headers | | | | |
| Modified | -- | -- | -- | -- |
| headers | | | | |
| Untouche | -- | -- | -- | -- |
| d | | | | |
| headers | | | | |
+----------+---------+-------------------+-------------------+------+
Storing: Summary of the use of headers from Internet to not-RPL-
aware-leaf
5.9. Example of Flow from RPL-aware-leaf to RPL-aware-leaf
In [RFC6550] RPL allows a simple one-hop P2P optimization for both
storing and non-storing networks. A node may send a P2P packet
destined to a one-hop neighbor directly to that node. Section 9 in
[RFC6550].
In this case the flow comprises:
6LN --> 6LR --> common parent (6LR) --> 6LR --> 6LN
This case is assumed in the same RPL Domain. In the common parent,
the direction of RPI is changed (from increasing to decreasing the
rank).
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+-------------+-------+---------------+---------------+-----+-------+
| Header | 6LN | 6LR | 6LR (common | 6LR | 6LN |
| | src | | parent) | | dst |
+-------------+-------+---------------+---------------+-----+-------+
| Inserted | RPI | -- | -- | -- | -- |
| headers | | | | | |
| Removed | -- | -- | -- | -- | RPI |
| headers | | | | | |
| Re-added | -- | -- | -- | -- | -- |
| headers | | | | | |
| Modified | -- | RPI | RPI | -- | -- |
| headers | | (decreasing | (increasing | | |
| | | rank) | rank) | | |
| Untouched | -- | -- | -- | -- | -- |
| headers | | | | | |
+-------------+-------+---------------+---------------+-----+-------+
Storing: Summary of the use of headers for RPL-aware-leaf to RPL-
aware-leaf
5.10. Example of Flow from RPL-aware-leaf to non-RPL-aware-leaf
In this case the flow comprises:
6LN --> 6LR --> common parent (6LR) --> 6LR --> not-RPL-aware 6LN
Somehow, the sender has to know that the receiver is not RPL aware,
and needs to know 6LR, and not even the root knows where the 6LR is
(in storing mode). This case FAILS.
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+-------+------------+------------+-------------+-------------+-----+
| Heade | 6LN | 6LR | 6LR (common | 6LR | IPv |
| r | | | parent) | | 6 |
+-------+------------+------------+-------------+-------------+-----+
| Inser | IPv6-in- | -- | -- | -- | -- |
| ted h | IPv6(RPI) | | | | |
| eader | | | | | |
| s | | | | | |
| Remov | -- | -- | -- | IPv6-in- | -- |
| ed he | | | | IPv6(RPI) | |
| aders | | | | | |
| Re- | -- | -- | -- | -- | -- |
| added | | | | | |
| heade | | | | | |
| rs | | | | | |
| Modif | -- | IPv6-in- | IPv6-in- | -- | -- |
| ied h | | IPv6(RPI) | IPv6(RPI) | | |
| eader | | | | | |
| s | | | | | |
| Untou | -- | -- | -- | -- | -- |
| ched | | | | | |
| heade | | | | | |
| rs | | | | | |
+-------+------------+------------+-------------+-------------+-----+
Storing: Summary of the use of headers from RPL-aware-leaf to not-
RPL-aware-leaf
5.11. Example of Flow from not-RPL-aware-leaf to RPL-aware-leaf
In this case the flow comprises:
not-RPL-aware 6LN --> 6LR --> common parent (6LR) --> 6LR --> 6LN
The 6LR that get the packet from IPv6 node, insert the RPI header
encapsulated in IPv6-in-IPv6 header with destination to 6LN, the
common parent change the direction of RPI and finally it is removed
by 6LN.
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+-------+----+------------+-------------+-------------+-------------+
| Heade | IP | 6LR | common | 6LR | 6LN |
| r | v6 | | parent | | |
| | | | (6LR) | | |
+-------+----+------------+-------------+-------------+-------------+
| Inser | -- | IPv6-in- | -- | -- | -- |
| ted h | | IPv6(RPI) | | | |
| eader | | | | | |
| s | | | | | |
| Remov | -- | -- | -- | -- | IPv6-in- |
| ed he | | | | | IPv6(RPI) |
| aders | | | | | |
| Re- | -- | -- | -- | -- | -- |
| added | | | | | |
| heade | | | | | |
| rs | | | | | |
| Modif | -- | -- | IPv6-in- | IPv6-in- | -- |
| ied h | | | IPv6(RPI) | IPv6(RPI) | |
| eader | | | | | |
| s | | | | | |
| Untou | -- | -- | -- | -- | -- |
| ched | | | | | |
| heade | | | | | |
| rs | | | | | |
+-------+----+------------+-------------+-------------+-------------+
Storing: Summary of the use of headers from not-RPL-aware-leaf to
RPL-aware-leaf
5.12. Example of Flow from not-RPL-aware-leaf to not-RPL-aware-leaf
In this case the flow comprises:
not-RPL-aware 6LN --> 6LR --> root (6LBR) --> 6LR --> not-RPL-aware
6LN
The problem to solve is how to indicate where to send the packet when
get into LLN.
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+---------+-----+----------------+---------+-----------------+------+
| Header | IPv | 6LR | 6LR | 6LR | IPv6 |
| | 6 | | (common | | dst |
| | src | | parent) | | |
+---------+-----+----------------+---------+-----------------+------+
| Inserte | -- | IPv6-in- | -- | -- | -- |
| d | | IPv6(RPI) | | | |
| headers | | | | | |
| Removed | -- | -- | -- | IPv6-in- | -- |
| headers | | | | IPv6(RPI) | |
| Re- | -- | -- | -- | -- | -- |
| added | | | | | |
| headers | | | | | |
| Modifie | -- | -- | -- | -- | -- |
| d | | | | | |
| headers | | | | | |
| Untouch | -- | -- | -- | -- | -- |
| ed | | | | | |
| headers | | | | | |
+---------+-----+----------------+---------+-----------------+------+
Storing: Summary of the use of headers from not-RPL-aware-leaf to
not-RPL-aware-leaf
6. Non Storing mode
6.1. Example of Flow from RPL-aware-leaf to root
In non-storing mode the leaf node uses Hop-By-Hop option (RFC 6553)
to indicate the routing information to send messages to the DODAG
root, this message is going to be analyzed in each node until arrive
the DODAG root.
In this case not need to use IPv6-in-IPv6 because no header is not
going to be removed, neither RH3, the flow comprises:
RPL-aware-leaf (6LN) --> 6LR --> root (6LBR)
This case is the same case as storing mode.
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+-------------------+-----+------+------+
| Header | 6LN | 6LR | 6LBR |
+-------------------+-----+------+------+
| Inserted headers | RPI | -- | -- |
| Removed headers | -- | -- | RPI |
| Re-added headers | -- | -- | -- |
| Modified headers | -- | RPI | -- |
| Untouched headers | -- | -- | -- |
+-------------------+-----+------+------+
Non Storing: Summary of the use of headers from RPL-aware-leaf to
root
6.2. Example of Flow from root to RPL-aware-leaf
In this case the flow comprises:
root (6LBR)--> 6LR --> RPL-aware-leaf (6LN)
6LBR might instert RPI header, and the rute is indicated in RH3. 6LR
updated RH3 and 6LN remove these headers.
+-------------------+----------------------+------+----------+
| Header | 6LBR | 6LR | 6LN |
+-------------------+----------------------+------+----------+
| Inserted headers | (optional: RPI), RH3 | -- | -- |
| Removed headers | -- | -- | RH3,RPI |
| Re-added headers | -- | -- | -- |
| Modified headers | -- | RH3 | -- |
| Untouched headers | -- | -- | -- |
+-------------------+----------------------+------+----------+
Non Storing: Summary of the use of headers from root to RPL-aware-
leaf
6.3. Example of Flow from root to not-RPL-aware-leaf
In this case the flow comprises:
root (6LBR)--> 6LR --> not-RPL-aware-leaf (IPv6 node)
In 6LBR the RH3 is added, and modified in 6LR where is fully
consumed, but left there. If the RPI is present, the IPv6 node which
does not understand it will drop it. To avoid it the RPI should be
removed before reach IPv6 node or it is recommended that RPI be
omitted. An IPv6-in-IPv6 header should be necessary in this case.
The DAO from 6LR about IPv6 could say if that the final IPv6 is not
RPL (RPI) capable.
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+-------------------+------+-----+------+
| Header | 6LBR | 6LR | IPv6 |
+-------------------+------+-----+------+
| Inserted headers | RH3 | -- | -- |
| Removed headers | -- | -- | -- |
| Re-added headers | -- | -- | -- |
| Modified headers | -- | RH3 | -- |
| Untouched headers | -- | -- | -- |
+-------------------+------+-----+------+
Non Storing: Summary of the use of headers from root to not-RPL-
aware-leaf
6.4. Example of Flow from not-RPL-aware-leaf to root
In this case the flow comprises:
IPv6-node --> 6LR1 --> 6LR2 --> root (6LBR)
In this case the RPI is encapsulated in the first 6LR, and is not
modified in the followings 6LRs.
+-------------+------+-------------------+------+-------------------+
| Header | IPv6 | 6LR1 | 6LR2 | 6LBR |
+-------------+------+-------------------+------+-------------------+
| Inserted | -- | IPv6-in-IPv6(RPI) | -- | -- |
| headers | | | | |
| Removed | -- | -- | -- | IPv6-in-IPv6(RPI) |
| headers | | | | |
| Re-added | -- | -- | -- | -- |
| headers | | | | |
| Modified | -- | -- | -- | -- |
| headers | | | | |
| Untouched | -- | IPv6-in-IPv6(RPI) | -- | -- |
| headers | | | | |
+-------------+------+-------------------+------+-------------------+
Non Storing: Summary of the use of headers from not-RPL-aware-leaf to
root
6.5. Example of Flow from RPL-aware-leaf to Internet
In this case the flow comprises:
RPL-aware-leaf (6LN) --> 6LR --> root (6LBR) --> Internet
This case requires that the network is awareness of what is external
to the LLN. Internet node never sees RPI or IPv6-in-IPv6 header. In
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the 6LBR the flow label is computed if it is zero. RPI remains
unmodified.
+----------+-------------------+-----+-------------------+----------+
| Header | 6LN | 6LR | 6LBR | Internet |
+----------+-------------------+-----+-------------------+----------+
| Inserted | IPV6-in-IPv6(RPI) | -- | -- | -- |
| headers | | | | |
| Removed | -- | -- | IPV6-in-IPv6(RPI) | -- |
| headers | | | | |
| Re-added | -- | -- | -- | -- |
| headers | | | | |
| Modified | -- | -- | -- | -- |
| headers | | | | |
| Untouche | -- | RPI | -- | -- |
| d | | | | |
| headers | | | | |
+----------+-------------------+-----+-------------------+----------+
Non Storing: Summary of the use of headers from RPL-aware-leaf to
Internet
6.6. Example of Flow from Internet to RPL-aware-leaf
In this case the flow comprises:
Internet --> root (6LBR) --> 6LR --> RPL-aware-leaf (6LN)
If the last RH3 entry is the 6LR, then the IPv6-in-IPv6 will be
removed there, if the last entry is the 6LN, then the RH3 will go all
the way to the leaf. In 6LBR the flow label should be set to zero.
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+---------+--------+-------------------------+----------------+-----+
| Header | Intern | 6LBR | 6LR | 6LN |
| | et | | | |
+---------+--------+-------------------------+----------------+-----+
| Inserte | -- | IPv6-in- | -- | -- |
| d | | IPv6(RH3,optional:RPI) | | |
| headers | | | | |
| Removed | -- | -- | IPv6-in-IPv6 | -- |
| headers | | | can be removed | |
| | | | if RH3 | |
| | | | consumed | |
| Re- | -- | -- | -- | -- |
| added | | | | |
| headers | | | | |
| Modifie | -- | -- | IPv6-in- | -- |
| d | | | IPv6(RH3) | |
| headers | | | | |
| Untouch | -- | -- | -- | -- |
| ed | | | | |
| headers | | | | |
+---------+--------+-------------------------+----------------+-----+
Non Storing: Summary of the use of headers from Internet to RPL-
aware-leaf
6.7. Example of Flow from not-RPL-aware-leaf to Internet
In this case the flow comprises:
not-RPL-aware-leaf (6LN) --> 6LR --> root (6LBR) --> Internet
In this case the flow label is recommended to be zero in the IPv6
node. no RPL headers are added in the IPv6 node, since it is ignorant
of RPL. Internet node does not see special headers. In 6LBR the
flow label is computed if it is zero.
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+----------+-----+-------------------+-------------------+----------+
| Header | IPv | 6LR | 6LBR | Internet |
| | 6 | | | |
+----------+-----+-------------------+-------------------+----------+
| Inserted | -- | IPv6-in-IPv6(RPI) | -- | -- |
| headers | | | | |
| Removed | -- | -- | IPv6-in-IPv6(RPI) | -- |
| headers | | | | |
| Re-added | -- | -- | -- | -- |
| headers | | | | |
| Modified | -- | -- | -- | -- |
| headers | | | | |
| Untouche | -- | -- | -- | -- |
| d | | | | |
| headers | | | | |
+----------+-----+-------------------+-------------------+----------+
Non Storing: Summary of the use of headers from not-RPL-aware-leaf to
Internet
6.8. Example of Flow from Internet to not-RPL-aware-leaf
In this case the flow comprises:
Internet --> root (6LBR) --> 6LR --> not-RPL-aware-leaf (6LN)
In this case the flow label in 6LBR should be set zero in 6LBR, where
RH3 is inserted and optionally RHI. RH3 must end at 6LR.
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+---------+--------+-------------------------+---------------+------+
| Header | Intern | 6LBR | 6LR | IPv6 |
| | et | | | |
+---------+--------+-------------------------+---------------+------+
| Inserte | -- | IPv6-in- | -- | -- |
| d | | IPv6(RH3,optional:RPI) | | |
| headers | | | | |
| Removed | -- | -- | IPv6-in- | -- |
| headers | | | IPv6(RH3, | |
| | | | RPI) | |
| Re- | -- | -- | -- | -- |
| added | | | | |
| headers | | | | |
| Modifie | -- | -- | -- | -- |
| d | | | | |
| headers | | | | |
| Untouch | -- | -- | -- | -- |
| ed | | | | |
| headers | | | | |
+---------+--------+-------------------------+---------------+------+
NonStoring: Summary of the use of headers from Internet to not-RPL-
aware-leaf
6.9. Example of Flow from RPL-aware-leaf to RPL-aware-leaf
In this case the flow comprises:
6LN --> 6LR --> root (6LBR) --> 6LR --> 6LN
This case comprises in the same RPL Domain. In the 6LN the RPI
header is inserted. In the 6LBR the RH3 header is inserted in a
IPv6-in-IPv6 header and removed at the 6LN destination.
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+-----------+------+---------------------+-----+--------------------+
| Header | 6LN | 6LBR | 6LR | 6LN dst |
| | src | | | |
+-----------+------+---------------------+-----+--------------------+
| Inserted | RPI | IPv6-in-IPv6(RH3 to | -- | -- |
| headers | | 6LN) | | |
| | | {IP,RPI,payload} | | |
| Removed | -- | -- | -- | IPv6-in-IPv6(RH3) |
| headers | | | | {IP,RPI,payload} |
| Re-added | -- | -- | -- | -- |
| headers | | | | |
| Modified | -- | -- | -- | -- |
| headers | | | | |
| Untouched | -- | -- | -- | -- |
| headers | | | | |
+-----------+------+---------------------+-----+--------------------+
Non Storing: Summary of the use of headers for RPL-aware-leaf to RPL-
aware-leaf
6.10. Example of Flow from RPL-aware-leaf to not-RPL-aware-leaf
In this case the flow comprises:
6LN --> 6LR --> root (6LBR) --> 6LR --> not-RPL-aware 6LN
The 6LN insert the RPI in a IPv6-in-IPv6 header, which is addressed
to 6LBR. The 6LBR remove this RPI header and insert a RH3 header
with an optional RPI. These headers are removed by 6LR before send
the packet to the IPv6 node.
+------------+-------------------+-------------+-------------+------+
| Header | 6LN | 6LBR | 6LR | IPv6 |
+------------+-------------------+-------------+-------------+------+
| Inserted | IPv6-in-IPv6(RPI) | IPIP(RH3, | -- | -- |
| headers | | opt RPI) | | |
| Removed | -- | IPIP(RPI) | IPIP(RH3, | -- |
| headers | | | opt RPI) | |
| Re-added | -- | -- | -- | -- |
| headers | | | | |
| Modified | -- | -- | -- | -- |
| headers | | | | |
| Untouched | -- | -- | -- | -- |
| headers | | | | |
+------------+-------------------+-------------+-------------+------+
Non Storing: Summary of the use of headers from RPL-aware-leaf to
not-RPL-aware-leaf
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6.11. Example of Flow from not-RPL-aware-leaf to RPL-aware-leaf
In this case the flow comprises:
not-RPL-aware 6LN --> 6LR --> root (6LBR) --> 6LR --> 6LN
RPI is added in 6LR until the root and then removed, then RH3 is
added and removed at destination.
+-------------------+------+------------+-----------+------------+
| Header | IPv6 | 6LR | 6LBR | 6LN |
+-------------------+------+------------+-----------+------------+
| Inserted headers | -- | IPIP(RPI) | IPIP(RH3) | -- |
| Removed headers | -- | IPIP(RPI) | -- | IPIP(RH3) |
| Re-added headers | -- | -- | -- | -- |
| Modified headers | -- | -- | -- | -- |
| Untouched headers | -- | -- | -- | -- |
+-------------------+------+------------+-----------+------------+
Non Storing: Summary of the use of headers from not-RPL-aware-leaf to
RPL-aware-leaf
6.12. Example of Flow from not-RPL-aware-leaf to not-RPL-aware-leaf
In this case the flow comprises:
not-RPL-aware 6LN --> 6LR --> root (6LBR) --> 6LR --> not-RPL-aware
6LN
RPI is added in 6LR until the root and then might be removed, then
RH3 is added. These headers are removed at 6LR before go to
destination.
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+--------------+------+-----------+-----------+--------------+------+
| Header | IPv6 | 6LR | 6LBR | 6LR | IPv6 |
+--------------+------+-----------+-----------+--------------+------+
| Inserted | -- | IPIP(RPI) | IPIP(RH3) | -- | -- |
| headers | | | | | |
| Removed | -- | -- | IPIP(RPI) | IPIP(RH3, | -- |
| headers | | | | opt RPI) | |
| Re-added | -- | -- | -- | -- | -- |
| headers | | | | | |
| Modified | -- | -- | -- | -- | -- |
| headers | | | | | |
| Untouched | -- | -- | -- | -- | -- |
| headers | | | | | |
+--------------+------+-----------+-----------+--------------+------+
Non Storing: Summary of the use of headers from not-RPL-aware-leaf to
not-RPL-aware-leaf
7. Future RPL work
There are cases from above that are not clear how to send the
information. It requires furhter analysis on how to proceed to send
the information from source to destination.
From the above cases, we have in storing mode:
- Flow from RPL-aware-leaf to non-RPL-aware-leaf: Somehow, the sender
has to know that the receiver is not RPL aware, and needs to know
6LR, and not even the root knows where the 6LR is located.
- Flow from not-RPL-aware-leaf to not-RPL-aware-leaf: The problem to
solve is how to indicate where to send the packet when get into LLN.
8. IANA Considerations
There are no IANA considerations related to this document.
9. Security Considerations
TODO.
10. Acknowledgments
This work is partially funded by the FP7 Marie Curie Initial Training
Network (ITN) METRICS project (grant agreement No. 607728).
The authors would like to acknowledge the review, feedback, and
comments of Thomas Watteyne, Xavier Vilajosana and Robert Cragie.
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To be completed with additional Acknowledgments.
11. References
11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
Low-Power and Lossy Networks", RFC 6550,
DOI 10.17487/RFC6550, March 2012,
<http://www.rfc-editor.org/info/rfc6550>.
[RFC6553] Hui, J. and JP. Vasseur, "The Routing Protocol for Low-
Power and Lossy Networks (RPL) Option for Carrying RPL
Information in Data-Plane Datagrams", RFC 6553,
DOI 10.17487/RFC6553, March 2012,
<http://www.rfc-editor.org/info/rfc6553>.
[RFC6554] Hui, J., Vasseur, JP., Culler, D., and V. Manral, "An IPv6
Routing Header for Source Routes with the Routing Protocol
for Low-Power and Lossy Networks (RPL)", RFC 6554,
DOI 10.17487/RFC6554, March 2012,
<http://www.rfc-editor.org/info/rfc6554>.
11.2. Informative References
[I-D.ietf-6tisch-architecture]
Thubert, P., "An Architecture for IPv6 over the TSCH mode
of IEEE 802.15.4", draft-ietf-6tisch-architecture-08 (work
in progress), May 2015.
[I-D.thubert-6lo-routing-dispatch]
Thubert, P., Bormann, C., Toutain, L., and R. Cragie, "A
Routing Header Dispatch for 6LoWPAN", draft-thubert-6lo-
routing-dispatch-06 (work in progress), August 2015.
[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
2014, <http://www.rfc-editor.org/info/rfc7102>.
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Authors' Addresses
Maria Ines Robles
Ericsson
Hirsalantie 11
Jorvas 02420
Finland
Email: maria.ines.robles@ericsson.com
Michael C. Richardson
Sandelman Software Works
470 Dawson Avenue
Ottawa, ON K1Z 5V7
CA
Email: mcr+ietf@sandelman.ca
URI: http://www.sandelman.ca/
Pascal Thubert
Cisco Systems, Inc
Village d'Entreprises Green Side 400, Avenue de Roumanille
Batiment T3, Biot - Sophia Antipolis 06410
France
Email: pthubert@cisco.com
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