Transmission of IPv6 Packets over DECT Ultra Low Energy
The information below is for an old version of the document.
This is an older version of an Internet-Draft that was ultimately published as RFC 8105.
|Authors||Peter B. Mariager , Jens T. Petersen , Zach Shelby , Marco van de Logt , Dominique Barthel|
|RFC stream||Internet Engineering Task Force (IETF)|
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|Stream||WG state||WG Document|
|Document shepherd||Samita Chakrabarti|
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6Lo Working Group P. Mariager Internet-Draft J. Petersen, Ed. Intended status: Standards Track RTX A/S Expires: January 4, 2016 Z. Shelby ARM M. Van de Logt Gigaset Communications GmbH D. Barthel Orange Labs July 3, 2015 Transmission of IPv6 Packets over DECT Ultra Low Energy draft-ietf-6lo-dect-ule-02 Abstract DECT Ultra Low Energy is a low power air interface technology that is defined by the DECT Forum and specified by ETSI. The DECT air interface technology has been used world-wide in communication devices for more than 20 years, primarily carrying voice for cordless telephony but has also been deployed for data centric services. The DECT Ultra Low Energy is a recent addition to the DECT interface primarily intended for low-bandwidth, low-power applications such as sensor devices, smart meters, home automation etc. As the DECT Ultra Low Energy interface inherits many of the capabilities from DECT, it benefits from long range, interference free operation, world wide reserved frequency band, low silicon prices and maturity. There is an added value in the ability to communicate with IPv6 over DECT ULE such as for Internet of Things applications. This document describes how IPv6 is transported over DECT ULE using 6LoWPAN techniques. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Mariager, et al. Expires January 4, 2016 [Page 1] Internet-Draft IPv6 over DECT ULE July 2015 Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on January 4, 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 (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Notation . . . . . . . . . . . . . . . . . . 3 1.2. Terms Used . . . . . . . . . . . . . . . . . . . . . . . 3 2. DECT Ultra Low Energy . . . . . . . . . . . . . . . . . . . . 4 2.1. The DECT ULE Protocol Stack . . . . . . . . . . . . . . . 4 2.2. Link layer roles and topology . . . . . . . . . . . . . . 6 2.3. Addressing Model . . . . . . . . . . . . . . . . . . . . 6 2.4. MTU Considerations . . . . . . . . . . . . . . . . . . . 7 2.5. Additional Considerations . . . . . . . . . . . . . . . . 7 3. Specification of IPv6 over DECT ULE . . . . . . . . . . . . . 7 3.1. Protocol stack . . . . . . . . . . . . . . . . . . . . . 8 3.2. Link model . . . . . . . . . . . . . . . . . . . . . . . 8 3.3. Subnets and Internet connectivity scenarios . . . . . . . 12 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 5. Security Considerations . . . . . . . . . . . . . . . . . . . 14 6. ETSI Considerations . . . . . . . . . . . . . . . . . . . . . 14 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1. Normative References . . . . . . . . . . . . . . . . . . 15 8.2. Informative References . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 Mariager, et al. Expires January 4, 2016 [Page 2] Internet-Draft IPv6 over DECT ULE July 2015 1. Introduction DECT Ultra Low Energy (DECT ULE or just ULE) is an air interface technology building on the key fundamentals of traditional DECT / CAT-iq but with specific changes to significantly reduce the power consumption at the expense of data throughput. DECT ULE devices with requirements on power consumption will operate on special power optimized silicon, but can connect to a DECT Gateway supporting traditional DECT / CAT-iq for cordless telephony and data as well as the ULE extensions. DECT terminology operates with two major role definitions: The Portable Part (PP) is the power constrained device, while the Fixed Part (FP) is the Gateway or base station. This FP may be connected to the Internet. An example of a use case for DECT ULE is a home security sensor transmitting small amounts of data (few bytes) at periodic intervals through the FP, but is able to wake up upon an external event (burglar) and communicate with the FP. Another example incorporating both DECT ULE as well as traditional CAT-iq telephony is an elderly pendant (broche) which can transmit periodic status messages to a care provider using very little battery, but in the event of urgency, the elderly person can establish a voice connection through the pendant to an alarm service. It is expected that DECT ULE will be integrated into many residential gateways, as many of these already implements DECT CAT-iq for cordless telephony. DECT ULE can be added as a software option for the FP. It is desirable to consider IPv6 for DECT ULE devices due to the large address space and well-known infrastructure. This document describes how IPv6 is used on DECT ULE links to optimize power while maintaining the many benefits of IPv6 transmission. [RFC4944], [RFC6282] and [RFC6775] specify the transmission of IPv6 over IEEE 802.15.4. DECT ULE has many characteristics similar to those of IEEE 802.15.4, but also differences. Many of the mechanisms defined for transmission of IPv6 over IEEE 802.15.4 can be applied to the transmission of IPv6 on DECT ULE links. This document specifies how to map IPv6 over DECT ULE inspired by [RFC4944], [RFC6282], [RFC6775] and [I-D.ietf-6lo-btle]. 1.1. Requirements Notation 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 [RFC2119]. 1.2. Terms Used PP: DECT Portable Part, typically the sensor node FP: DECT Fixed Part, the gateway Mariager, et al. Expires January 4, 2016 [Page 3] Internet-Draft IPv6 over DECT ULE July 2015 LLME: Lower Layer Management Entity RFPI: Radio Fixed Part Identity IPEI: International Portable Equipment Identity TPUI: Temporary Portable User Identity PMID: Portable MAC Identity PVC: Permanent Virtual Circuit 6LN: DECT Portable part having a role as defined in [RFC6775] 6LBR: DECT Fixed Part having a role as defined in [RFC6775] 2. DECT Ultra Low Energy DECT ULE is a low power air interface technology that is designed to support both circuit switched for service, such as voice communication, and for packet mode data services at modest data rate. This draft is only addressing the packet mode data service of DECT ULE. 2.1. The DECT ULE Protocol Stack The DECT ULE protocol stack consists of the PHY layer operating at frequencies in the 1880 - 1920 MHz frequency band depending on the region and uses a symbol rate of 1.152 Mbps. Radio bearers are allocated by use of FDMA/TDMA/TDD technics. In its generic network topology, DECT is defined as a cellular network technology. However, the most common configuration is a star network with a single FP defining the network with a number of PP attached. The MAC layer supports both traditional DECT as this is used for services like discovery, pairing, security features etc. All these features have been reused from DECT. The DECT ULE device can switch to the ULE mode of operation, utilizing the new ULE MAC layer features. The DECT ULE Data Link Control (DLC) provides multiplexing as well as segmentation and re- assembly for larger packets from layers above. The DECT ULE layer also implements per-message authentication and encryption. The DLC layer ensures packet integrity and preserves packet order, but delivery is based on best effort. The current DECT ULE MAC layer standard supports low bandwidth data broadcast. However the usage of this broadcast service has not yet Mariager, et al. Expires January 4, 2016 [Page 4] Internet-Draft IPv6 over DECT ULE July 2015 been standardized for higher layers. This document is not considering usage of this DECT ULE MAC broadcast service in current version. In general, communication sessions can be initiated from both FP and PP side. Depending on power down modes employed in the PP, latency may occur when initiating sessions from FP side. MAC layer communication can take place using either connection oriented packet transfer with low overhead for short sessions or take place using connection oriented bearers including media reservation. The MAC layer autonomously selects the radio spectrum positions that are available within the band and can rearrange these to avoid interference. The MAC layer has built-in retransmission procedures in order to improve transmission reliability. The DECT ULE device will typically incorporate an Application Programmers Interface (API) as well as common elements known as Generic Access Profile (GAP) for enrolling into the network. The DECT ULE stack establishes a permanent virtual circuit (PVC) for the application layers and provides support for a range of different application protocols. The used application protocol is negotiated between the PP and FP when the PVC communication service is established. This draft defines 6LoWPAN as one of the possible protocols to negotiate. +----------------------------------------+ | Applications | +----------------------------------------+ | Generic Access | ULE Profile | | Profile | | +----------------------------------------+ | DECT/Service API | ULE Data API | +--------------------+-------------------+ | LLME | NWK (MM,CC)| | +--------------------+-------------------+ | DECT DLC | DECT ULE DLC | +--------------------+-------------------+ | MAC Layer | +--------------------+-------------------+ | Physical Layer | +--------------------+-------------------+ (C-plane) (U-plane) Figure 1: DECT ULE Protocol Stack Mariager, et al. Expires January 4, 2016 [Page 5] Internet-Draft IPv6 over DECT ULE July 2015 The DECT ULE stack can be divided into control (C-plane) and user- data (U-plane) parts shown to the left and to the right in figure 1, respectively. 2.2. Link layer roles and topology A FP is assumed to be less constrained than a PP. Hence, in the primary scenario FP and PP will act as 6LBR and a 6LN, respectively. This document does only address this primary scenario. In DECT ULE, at link layer the communication only takes place between a FP and a PP. A FP is able to handle multiple simultaneous connections with a number of PP. Hence, in a DECT ULE network using IPv6, a radio hop is equivalent to an IPv6 link and vice versa. [DECT ULE PP]-----\ /-----[DECT ULE PP] \ / [DECT ULE PP]-------+[DECT ULE FP]+-------[DECT ULE PP] / \ [DECT ULE PP]-----/ \-----[DECT ULE PP] Figure 2: DECT ULE star topology DECT ULE repeaters are not considered in this document. 2.3. Addressing Model Each DECT PP is assigned an IPEI during manufacturing. This identity has the size of 40 bits and is DECT globally unique for the PP and can be used to constitute the MAC address. However, it cannot be used to derive a globally unique IID. When bound to a FP, a PP is assigned a 20 bit TPUI which is unique within the FP. This TPUI is used for addressing (layer 2) in messages between FP and PP. Each DECT FP is assigned a RFPI during manufacturing. This identity has the size of 40 bits and is globally unique for a FP and can be used to constitute the MAC address. However, it cannot be used to derive a globally unique IID. Alternatively each DECT PP and DECT FP can be assigned a unique (IEEE) MAC-48 address additionally to the DECT identities to be used by the 6LoWPAN. With such an approach, the FP and PP have to Mariager, et al. Expires January 4, 2016 [Page 6] Internet-Draft IPv6 over DECT ULE July 2015 implement a mapping between used MAC-48 addresses and DECT identities. 2.4. MTU Considerations Generally the DECT ULE FP and PP may be generating data that fits into a single MAC Layer packet (38 octets) for periodically transferred information, depending on application. IP data packets may be much larger and hence MTU size should be the size of the IP data packet. The DECT ULE DLC procedures supports segmentation and reassembly of any MTU size below 65536 octets, but most implementations do only support smaller values. The default MTU size in DECT ULE is 500 octets, but it SHALL be configured to fit the requirements from IPv6 data packets, hence [RFC4944] fragmentation/ reassembly is not required. It is expected that the LOWPAN_IPHC packet will fulfill all the requirements for header compression without spending unnecessary overhead for mesh addressing. It is important to realize that the usage of larger packets will be at the expense of battery life, as a large packet inside the DECT ULE stack will be fragmented into several or many MAC layer packets, each consuming power to transmit / receive. 2.5. Additional Considerations The DECT ULE standard allows PP to be registered (bind) to multiple FP and roaming between these FP. This draft does not consider the scenarios of PP roaming between multiple FP. The use of repeater functionality is also not considered in this draft. 3. Specification of IPv6 over DECT ULE Before any IP-layer communications can take place over DECT ULE, DECT ULE enabled nodes such as 6LNs and 6LBRs have to find each other and establish a suitable link-layer connection. The obtain-access-rights registration and location registration procedures are documented by ETSI in the specifications [EN300.175-part1-7], [TS102.939-1] and [TS102.939-2]. DECT ULE technology sets strict requirements for low power consumption and thus limits the allowed protocol overhead. 6LoWPAN standards [RFC4944], [RFC6775], and [RFC6282] provide useful functionality for reducing overhead which can be applied to DECT ULE. This functionality comprises link-local IPv6 addresses and stateless IPv6 address autoconfiguration, Neighbor Discovery and header compression. Mariager, et al. Expires January 4, 2016 [Page 7] Internet-Draft IPv6 over DECT ULE July 2015 The ULE 6LoWPAN adaptation layer can run directly on this U-plane DLC layer. Figure 3 illustrates IPv6 over DECT ULE stack. A significant difference between IEEE 802.15.4 and DECT ULE is that the former supports both star and mesh topology (and requires a routing protocol), whereas DECT ULE in it's primary configuration does not support the formation of multihop networks at the link layer. In consequence, the mesh header defined in [RFC4944] for mesh under routing MUST NOT be used in DECT ULE networks. In addition, a DECT ULE PP node MUST NOT play the role of a 6LoWPAN Router (6LR). 3.1. Protocol stack In order to enable transmission of IPv6 packets over DECT ULE, a Permanent Virtual Circuit (PVC) has to be opened between FP and PP. This MUST be done by setting up a service call from PP to FP. The PP SHALL specify the <<IWU-ATTRIBUTES>> in a service-change (other) message before sending a service-change (resume) message as defined in [TS102.939-1]. The <<IWU-ATTRIBTES>> SHALL define the ULE Application Protocol Identifier to 0x06 and the MTU size to 1280 octets or larger. The FP MUST send a service-change-accept (resume) containing a valid paging descriptor. The PP MUST be pageable. +-------------------+ | UDP/TCP/other | +-------------------+ | IPv6 | +-------------------+ |6LoWPAN adapted to | | DECT ULE | +-------------------+ | DECT ULE DLC | +-------------------+ | DECT ULE MAC | +-------------------+ | DECT ULE PHY | +-------------------+ Figure 3: IPv6 over DECT ULE Stack 3.2. Link model The general model is that IPv6 is layer 3 and DECT ULE MAC+DLC is layer 2. The DECT ULE implements fragmentation and reassembly functionality and [RFC4944] fragmentation and reassembly function MUST NOT be used. Since IPv6 requires MTU size of at least 1280 Mariager, et al. Expires January 4, 2016 [Page 8] Internet-Draft IPv6 over DECT ULE July 2015 octets, the DECT ULE connection (PVC) MUST be configured with equivalent MTU size. Per this specification, the IPv6 header compression format specified in [RFC6282] MUST be used. The IPv6 payload length can be derived from the ULE DLC packet length and the possibly elided IPv6 address can be reconstructed from the link-layer address, used at the time of DECT ULE connection establishment, from the ULE MAC packet address, compression context if any, and from address registration information (see Section 3.2.2). Due to DECT ULE star topology, each branch of the star is considered to be an individual link and thus the PPs cannot directly hear one another and cannot talk to one another with link-local addresses. However, the FP acts as a 6LBR for communication between the PPs. After the FP and PPs have connected at the DECT ULE level, the link can be considered up and IPv6 address configuration and transmission can begin. The FP ensures address collisions do not occur. 3.2.1. Stateless address autoconfiguration A DECT ULE 6LN performs stateless address autoconfiguration as per [RFC4862]. Following the guidance of [RFC7136], a 64-bit Interface identifier (IID) for a DECT ULE interface MAY be formed by utilizing a MAC-48 device address as defined in [RFC2464] "IPv6 over Ethernet" specification. Alternatively, the DECT device addresses IPEI, RFPI or TPUI, MAY be used instead to derive the IID. These DECT devices addresses consisting of 40, 40 and 20 bits respectively, MUST be expanded with leading bits to form a 48 bit address. Least significant bit of this address is the last bit in network order. The expanded leading bits are all zeros except for 7th bit indicating not global unique. First bit is set to a one for addresses derived from the RFPI and 2nd bit is set to one when the address is derived from the PMID. For example from IPEI=01.23.45.67.89 is derived MAC address equal 02:01:23:45:67:89 and from PMID=0.01.23 is derived MAC address equal 42:00:00:00:01:23. As defined in [RFC4291], the IPv6 link-local address for a DECT ULE node is formed by appending the IID, to the prefix FE80::/64, as shown in Figure 4. Mariager, et al. Expires January 4, 2016 [Page 9] Internet-Draft IPv6 over DECT ULE July 2015 10 bits 54 bits 64 bits +----------+-----------------+----------------------+ |1111111010| zeros | Interface Identifier | +----------+-----------------+----------------------+ Figure 4: IPv6 link-local address in DECT ULE A 6LN MUST join the all-nodes multicast address. After link-local address configuration, 6LN sends Router Solicitation messages as described in [RFC4861] Section 6.3.7. For non-link-local addresses a 64-bit IID MAY be formed by utilizing a MAC-48 device address. A 6LN can also use a randomly generated IID (see Section 3.2.2), for example, as discussed in [I-D.ietf-6man- default-iids], or use alternative schemes such as Cryptographically Generated Addresses (CGA) [RFC3972], privacy extensions [RFC4941], Hash-Based Addresses (HBA, [RFC5535]), or DHCPv6 [RFC3315]. The non- link-local addresses 6LN generates MUST be registered with 6LBR as described in Section 3.2.2. The means for a 6LBR to obtain an IPv6 prefix for numbering the DECT ULE network is out of scope of this document, but can be, for example, accomplished via DHCPv6 Prefix Delegation [RFC3633] or by using Unique Local IPv6 Unicast Addresses (ULA) [RFC4193]. Due to the link model of the DECT ULE the 6LBR MUST set the "on-link" flag (L) to zero in the Prefix Information Option [RFC4861]. This will cause 6LNs to always send packets to the 6LBR, including the case when the destination is another 6LN using the same prefix. 3.2.2. Neighbor discovery 'Neighbor Discovery Optimization for IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs)' [RFC6775] describes the neighbor discovery approach as adapted for use in several 6LoWPAN topologies, including the mesh topology. As DECT ULE is considered not to support mesh networks, hence only those aspects that apply to a star topology are considered. The following aspects of the Neighbor Discovery optimizations [RFC6775] are applicable to DECT ULE 6LNs: 1. For sending Router Solicitations and processing Router Advertisements the DECT ULE 6LNs MUST, respectively, follow Sections 5.3 and 5.4 of the [RFC6775]. Mariager, et al. Expires January 4, 2016 [Page 10] Internet-Draft IPv6 over DECT ULE July 2015 2. A DECT ULE 6LN MUST NOT register its link-local address. A DECT ULE 6LN MUST register its non-link-local addresses with the 6LBR by sending a Neighbor Solicitation (NS) message with the Address Registration Option (ARO) and process the Neighbor Advertisement (NA) accordingly. The NS with the ARO option MUST be sent irrespective of the method used to generate the IID. The 6LN MUST register only one IPv6 address per available IPv6 prefix. 3.2.3. Unicast and Multicast address mapping The DECT MAC layer broadcast service is considered inadequate for IP multicast. Hence traffic is always unicast between two DECT ULE nodes. Even in the case where a 6LBR is attached to multiple 6LNs, the 6LBR cannot do a multicast to all the connected 6LNs. If the 6LBR needs to send a multicast packet to all its 6LNs, it has to replicate the packet and unicast it on each link. However, this may not be energy- efficient and particular care should be taken if the FP is battery- powered. In the opposite direction, a 6LN can only transmit data to or through the 6LBR. Hence, when a 6LN needs to transmit an IPv6 multicast packet, the 6LN will unicast the corresponding DECT ULE packet to the 6LBR. The 6LBR will then forward the multicast packet to other 6LNs. 3.2.4. Header Compression Header compression as defined in [RFC6282], which specifies the compression format for IPv6 datagrams on top of IEEE 802.15.4, is REQUIRED in this document as the basis for IPv6 header compression on top of DECT ULE. All headers MUST be compressed according to [RFC6282] encoding formats. The DECT ULE's star topology structure and ARO can be exploited in order to provide a mechanism for addess compression. The following text describes the principles of IPv6 address compression on top of DECT ULE. 18.104.22.168. Link-local Header Compression In a link-local communication terminated at 6LN and 6LBR, both the IPv6 source and destination addresses MUST be elided, since the node knows that the packet is destined for it even if the packet does not have destination IPv6 address. A node SHALL learn the IID of the other endpoint of each DECT ULE connection it participates in. By exploiting this information, a node that receives a PDU containing an IPv6 packet can infer the corresponding IPv6 source address. A node MUST maintain a Neighbor Cache, in which the entries include both the IID of the neighbor and the Device Address that identifies the neighbor. For the type of communication considered in this Mariager, et al. Expires January 4, 2016 [Page 11] Internet-Draft IPv6 over DECT ULE July 2015 paragraph, the following settings MUST be used in the IPv6 compressed header: CID=0, SAC=0, SAM=11, DAC=0, DAM=11. 22.214.171.124. Non-link-local Header Compression To enable efficient header compression, the 6LBR MUST include 6LoWPAN Context Option (6CO) [RFC6775] for all prefixes the 6LBR advertises in Router Advertisements for use in stateless address autoconfiguration. When a 6LN transmits an IPv6 packet to a destination using global Unicast IPv6 addresses, if a context is defined for the prefix of the 6LNs global IPv6 address, the 6LN MUST indicate this context in the corresponding source fields of the compressed IPv6 header as per Section 3.1 of [RFC6282], and MUST elide the IPv6 source address. For this, the 6LN MUST use the following settings in the IPv6 compressed header: CID=1, SAC=1, SAM=11. In this case, the 6LBR can infer the elided IPv6 source address since 1) the 6LBR has previously assigned the prefix to the 6LNs; and 2) the 6LBR maintains a Neighbor Cache that relates the Device Address and the IID of the corresponding PP. If a context is defined for the IPv6 destination address, the 6LN MUST also indicate this context in the corresponding destination fields of the compressed IPv6 header, and MUST elide the prefix of the destination IPv6 address. For this, the 6LN MUST set the DAM field of the compressed IPv6 header as CID=1, DAC=1 and DAM=01 or DAM=11. Note that when a context is defined for the IPv6 destination address, the 6LBR can infer the elided destination prefix by using the context. When a 6LBR receives a IPv6 packet having a global Unicast IPv6 address, and the destination of the packet is a 6LN, if a context is defined for the prefix of the 6LN's global IPv6 address, the 6LBR MUST indicate this context in the corresponding destination fields of the compressed IPv6 header, and MUST elide the IPv6 destination address of the packet before forwarding it to the 6LN. For this, the 6LBR MUST set the DAM field of the IPv6 compressed header as DAM=11. CID and DAC MUST be set to CID=1 and DAC=1. If a context is defined for the prefix of the IPv6 source address, the 6LBR MUST indicate this context in the source fields of the compressed IPv6 header, and MUST elide that prefix as well. For this, the 6LBR MUST set the SAM field of the IPv6 compressed header as CID=1, SAC=1 and SAM=01 or SAM=11. 3.3. Subnets and Internet connectivity scenarios In a typical scenario, the DECT ULE network is connected to the Internet as shown in the Figure 5. In this scenario, the DECT ULE network is deployed as one subnet, using one /64 IPv6 prefix. The Mariager, et al. Expires January 4, 2016 [Page 12] Internet-Draft IPv6 over DECT ULE July 2015 6LBR is acting as router and forwarding packets between 6LNs and to and from Internet. A degenerate scenario can be imagined where a PP is acting as 6LBR and providing Internet connectivity for the FP. How the FP could then further provide Internet connectivity to other PP, possibly connected to the FP, is out of the scope of this document. 6LN \ ____________ \ / \ 6LN ---- 6LBR --- | Internet | / \____________/ / 6LN <-- DECT ULE --> Figure 5: DECT ULE network connected to the Internet In some scenarios, the DECT ULE network may transiently or permanently be an isolated network as shown in the Figure 6. In this case the whole DECT ULE network consists of a single subnet with multiple links, where 6LBR is routing packets between 6LNs. 6LN 6LN \ / \ / 6LN --- 6LBR --- 6LN / \ / \ 6LN 6LN <------ DECT ULE -----> Figure 6: Isolated DECT ULE network In the isolated network scenario, communications between 6LN and 6LBR can use IPv6 link-local methodology, but for communications between different PP, the FP has to act as 6LBR, number the network with ULA prefix [RFC4193], and route packets between PP. Mariager, et al. Expires January 4, 2016 [Page 13] Internet-Draft IPv6 over DECT ULE July 2015 4. IANA Considerations There are no IANA considerations related to this document. 5. Security Considerations The secure transmission of speech over DECT will be based on the DSAA2 and DSC2 work developed by the DF Security group / ETSI TC DECT and the ETSI SAGE Security expert group. DECT ULE communications are secured at the link-layer (DLC) by encryption and per-message authentication through CCM mode (Counter with CBC-MAC) similar to [RFC3610]. The underlying algorithm for providing encryption and authentication is AES128. The DECT ULE pairing procedure generates a master authentication key (UAK) and during location registration procedure or when the permanent virtual circuit are established, the session security keys are generated. Session security keys may be renewed regularly. The generated security keys (UAK and session security keys) are individual for each FP-PP binding, hence all PP in a system have different security keys. DECT ULE PPs do not use any shared encryption key. The IPv6 address configuration as described in Section 3.2.1 allows implementations the choice to support, for example, [I-D.ietf-6man- default-iids], [RFC3972], [RFC4941] or [RFC5535] for non-link-local addresses. 6. ETSI Considerations ETSI is standardizing a list of known application layer protocols that can use the DECT ULE permanent virtual circuit packet data service. Each protocol is identified by a unique known identifier, which is exchanged in the service-change procedure as defined in [TS102.939-1]. The IPv6/6LoWPAN as described in this document is considered as an application layer protocol on top of DECT ULE. In order to provide interoperability between 6LoWPAN / DECT ULE devices a common protocol identifier for 6LoWPAN is standardized by ETSI. The ETSI DECT ULE Application Protocol Identifier is specified to 0x06 for 6LoWPAN [TS102.939-1]. 7. Acknowledgements We are grateful to the members of the IETF 6lo working group; this document borrows liberally from their work. Mariager, et al. Expires January 4, 2016 [Page 14] Internet-Draft IPv6 over DECT ULE July 2015 Ralph Droms has provided valuable feedback for this draft. 8. References 8.1. Normative References [EN300.175-part1-7] ETSI, "Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI);", March 2015. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet Networks", RFC 2464, December 1998. [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, December 2003. [RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast Addresses", RFC 4193, October 2005. [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, February 2006. [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007. [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, September 2007. [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy Extensions for Stateless Address Autoconfiguration in IPv6", RFC 4941, September 2007. [RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler, "Transmission of IPv6 Packets over IEEE 802.15.4 Networks", RFC 4944, September 2007. [RFC6282] Hui, J. and P. Thubert, "Compression Format for IPv6 Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, September 2011. Mariager, et al. Expires January 4, 2016 [Page 15] Internet-Draft IPv6 over DECT ULE July 2015 [RFC6775] Shelby, Z., Chakrabarti, S., Nordmark, E., and C. Bormann, "Neighbor Discovery Optimization for IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs)", RFC 6775, November 2012. [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 Interface Identifiers", RFC 7136, February 2014. [TS102.939-1] ETSI, "Digital Enhanced Cordless Telecommunications (DECT); Ultra Low Energy (ULE); Machine to Machine Communications; Part 1: Home Automation Network (phase 1)", March 2015. [TS102.939-2] ETSI, "Digital Enhanced Cordless Telecommunications (DECT); Ultra Low Energy (ULE); Machine to Machine Communications; Part 2: Home Automation Network (phase 2)", March 2015. 8.2. Informative References [I-D.ietf-6lo-btle] Nieminen, J., Savolainen, T., Isomaki, M., Patil, B., Shelby, Z., and C. Gomez, "IPv6 over BLUETOOTH(R) Low Energy", draft-ietf-6lo-btle-14 (work in progress), June 2015. [I-D.ietf-6man-default-iids] Gont, F., Cooper, A., Thaler, D., and S. LIU, "Recommendation on Stable IPv6 Interface Identifiers", draft-ietf-6man-default-iids-04 (work in progress), June 2015. [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [RFC3610] Whiting, D., Housley, R., and N. Ferguson, "Counter with CBC-MAC (CCM)", RFC 3610, September 2003. [RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)", RFC 3972, March 2005. [RFC5535] Bagnulo, M., "Hash-Based Addresses (HBA)", RFC 5535, June 2009. Mariager, et al. Expires January 4, 2016 [Page 16] Internet-Draft IPv6 over DECT ULE July 2015 Authors' Addresses Peter B. Mariager RTX A/S Stroemmen 6 DK-9400 Noerresundby Denmark Email: email@example.com Jens Toftgaard Petersen (editor) RTX A/S Stroemmen 6 DK-9400 Noerresundby Denmark Email: firstname.lastname@example.org Zach Shelby Sensinode 150 Rose Orchard San Jose, CA 95134 USA Email: email@example.com Marco van de Logt Gigaset Communications GmbH Frankenstrasse 2 D-46395 Bocholt Germany Email: firstname.lastname@example.org Dominique Barthel Orange Labs 28 chemin du Vieux Chene 38243 Meylan France Email: email@example.com Mariager, et al. Expires January 4, 2016 [Page 17]