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diff --git a/doc/rfc/rfc3753.txt b/doc/rfc/rfc3753.txt new file mode 100644 index 0000000..512c5a1 --- /dev/null +++ b/doc/rfc/rfc3753.txt @@ -0,0 +1,2019 @@ + + + + + + +Network Working Group J. Manner, Ed. +Request for Comments: 3753 M. Kojo, Ed. +Category: Informational June 2004 + + + Mobility Related Terminology + +Status of this Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Copyright Notice + + Copyright (C) The Internet Society (2004). + +Abstract + + There is a need for common definitions of terminology in the work to + be done around IP mobility. This document defines terms for mobility + related terminology. The document originated out of work done in the + Seamoby Working Group but has broader applicability for terminology + used in IETF-wide discourse on technology for mobility and IP + networks. Other working groups dealing with mobility may want to + take advantage of this terminology. + +Table of Contents + + 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 2 + 2. General Terms . . . . . . . . . . . . . . . . . . . . . . . . 2 + 3. Mobile Access Networks and Mobile Networks. . . . . . . . . . 10 + 4. Handover Terminology. . . . . . . . . . . . . . . . . . . . . 15 + 4.1. Scope of Handover . . . . . . . . . . . . . . . . . . . 16 + 4.2. Handover Control. . . . . . . . . . . . . . . . . . . . 17 + 4.3. Simultaneous connectivity to Access Routers . . . . . . 19 + 4.4. Performance and Functional Aspects. . . . . . . . . . . 19 + 4.5. Micro Diversity, Macro Diversity, and IP Diversity. . . 21 + 4.6. Paging, and Mobile Node States and Modes. . . . . . . . 22 + 4.7. Context Transfer. . . . . . . . . . . . . . . . . . . . 24 + 4.8. Candidate Access Router Discovery . . . . . . . . . . . 24 + 4.9. Types of Mobility . . . . . . . . . . . . . . . . . . . 25 + 5. Specific Terminology for Mobile Ad-Hoc Networking . . . . . . 26 + 6. Security-related Terminology. . . . . . . . . . . . . . . . . 27 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 28 + 8. Contributors. . . . . . . . . . . . . . . . . . . . . . . . . 28 + 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 29 + 10. Informative References. . . . . . . . . . . . . . . . . . . . 29 + + + +Manner & Kojo Informational [Page 1] + +RFC 3753 Mobility Related Terminology June 2004 + + + 11. Appendix A - Index of Terms . . . . . . . . . . . . . . . . . 31 + 12. Authors' Addresses. . . . . . . . . . . . . . . . . . . . . . 35 + 13. Full Copyright Statement. . . . . . . . . . . . . . . . . . . 36 + +1. Introduction + + This document presents terminology to be used for documents and + discussions within the Seamoby Working Group. Other mobility related + working groups could take advantage of this terminology, in order to + create a common terminology for the area of mobility in IP networks. + + Some terms and their definitions that are not directly related to the + IP world are included for the purpose of harmonizing the terminology. + For example, 'Access Point' and 'base station' refer to the same + component, from the point of view of IP, but 'Access Router' has a + very different meaning. The presented terminology may also, it is + hoped, be adequate to cover mobile ad-hoc networks. + + The proposed terminology is not meant to assert any new terminology. + Rather the authors would welcome discussion on more exact definitions + as well as missing or unnecessary terms. This work is a + collaborative enterprise between people from many different + engineering backgrounds and so already presents a first step in + harmonizing the terminology. + + The terminology in this document is divided into several sections. + First, there is a list of terms for general use and mobile access + networks followed by terms related to handovers, and finally some + terms used within the MANET and NEMO working groups. + +2. General Terms + + Bandwidth + + The total width of the frequency band available to or used by a + communications channel. Usually measured in Hertz (Hz). The + bandwidth of a channel limits the available channel capacity. + + Bandwidth utilization + + The actual rate of information transfer achieved over a link, + expressed as a percentage of the theoretical maximum channel + capacity on that link, according to Shannon's Law. + + + + + + + + +Manner & Kojo Informational [Page 2] + +RFC 3753 Mobility Related Terminology June 2004 + + + Beacon + + A control message broadcast by a node (especially, a base station) + informing all the other nodes in its neighborhood of the + continuing presence of the broadcasting node, possibly along with + additional status or configuration information. + + Binding Update (BU) + + A message indicating a mobile node's current mobility binding, and + in particular its care-of address. + + Care-of-Address (CoA) + + An IP address associated with a mobile node while visiting a + foreign link; the subnet prefix of this IP address is a foreign + subnet prefix. A packet addressed to the mobile node which + arrives at the mobile node's home network when the mobile node is + away from home and has registered a Care-of Address will be + forwarded to that address by the Home Agent in the home network. + + Channel + + A subdivision of the physical medium allowing possibly shared + independent uses of the medium. Channels may be made available by + subdividing the medium into distinct time slots, or distinct + spectral bands, or decorrelated coding sequences. + + Channel access protocol + + A protocol for mediating access to, and possibly allocation of, + the various channels available within the physical communications + medium. Nodes participating in the channel access protocol agree + to communicate only when they have uncontested access to one of + the channels, so that there will be no interference. + + Channel capacity + + The total capacity of a link to carry information (typically bits) + per unit time. With a given bandwidth, the theoretical maximum + channel capacity is given by Shannon's Law. The actual channel + capacity of a channel is determined by the channel bandwidth, the + coding system used, and the signal to noise ratio. + + + + + + + + +Manner & Kojo Informational [Page 3] + +RFC 3753 Mobility Related Terminology June 2004 + + + Control message + + Information passed between two or more network nodes for + maintaining protocol state, which may be unrelated to any specific + application. + + Distance vector + + A characteristic of some routing protocols in which, for each + desired destination, a node maintains information about the + distance to that destination, and a vector (next hop) towards that + destination. + + Fairness + + A property of channel access protocols whereby a medium is made + fairly available to all eligible nodes on the link. Fairness does + not strictly imply equality, especially in cases where nodes are + given link access according to unequal priority or classification. + + Flooding + + The process of delivering data or control messages to every node + within the network under consideration. + + Foreign subnet prefix + + A bit string that consists of some number of initial bits of an IP + address which identifies a node's foreign link within the Internet + topology. + + Forwarding node + + A node which performs the function of forwarding datagrams from + one of its neighbors to another. + + Home Address (HoA) + + An IP address assigned to a mobile node, used as the permanent + address of the mobile node. This address is within the mobile + node's home link. Standard IP routing mechanisms will deliver + packets destined for a mobile node's home address to its home link + [9]. + + + + + + + + +Manner & Kojo Informational [Page 4] + +RFC 3753 Mobility Related Terminology June 2004 + + + Home Agent (HA) + + A router on a mobile node's home link with which the mobile node + has registered its current care-of address. While the mobile node + is away from home, the home agent intercepts packets on the home + link destined to the mobile node's home address, encapsulates + them, and tunnels them to the mobile node's registered care-of + address. + + Home subnet prefix + + A bit string that consists of some number of initial bits of an IP + address which identifies a node's home link within the Internet + topology (i.e., the IP subnet prefix corresponding to the mobile + node's home address, as defined in [9]). + + Interface + + A node's point of attachment to a link. + + IP access address + + An IP address (often dynamically allocated) which a node uses to + designate its current point of attachment to the local network. + The IP access address is typically to be distinguished from the + mobile node's home address; in fact, while visiting a foreign + network the IP access address may be considered unsuitable for use + as an end-point address by any but the most short-lived + applications. Instead, the IP access address is typically used as + the care-of address of the node. + + Link + + A communication facility or physical medium that can sustain data + communications between multiple network nodes, such as an Ethernet + (simple or bridged). A link is the layer immediately below IP. + In a layered network stack model, the Link Layer (Layer 2) is + normally below the Network (IP) Layer (Layer 3), and above the + Physical Layer (Layer 1). + + Asymmetric link + + A link with transmission characteristics which are different + depending upon the relative position or design characteristics of + the transmitter and the receiver of data on the link. For + instance, the range of one transmitter may be much higher than the + range of another transmitter on the same medium. + + + + +Manner & Kojo Informational [Page 5] + +RFC 3753 Mobility Related Terminology June 2004 + + + Link establishment + + The process of establishing a link between the mobile node and the + local network. This may involve allocating a channel, or other + local wireless resources, possibly including a minimum level of + service or bandwidth. + + Link-layer trigger (L2 Trigger) + + Information from the link layer that informs the network layer of + the detailed events involved in handover sequencing at the link + layer. L2 triggers are not specific to any particular link layer, + but rather represent generalizations of link layer information + available from a wide variety of link layer protocols [4]. + + Link state + + A characterization of some routing protocols in which every node + within the network is expected to maintain information about every + link within the network topology. + + Link-level acknowledgment + + A protocol strategy, typically employed over wireless media, + requiring neighbors to acknowledge receipt of packets (typically + unicast only) from the transmitter. Such strategies aim to avoid + packet loss or delay resulting from lack of, or unwanted + characteristics of, higher level protocols. Link-layer + acknowledgments are often used as part of Automatic Repeat-Request + (ARQ) algorithms for increasing link reliability. + + Local broadcast + + The delivery of data to every node within range of the + transmitter. + + Loop-free + + A property of routing protocols whereby the path taken by a data + packet from source to destination never traverses through the same + intermediate node twice before arrival at the destination. + + + + + + + + + + +Manner & Kojo Informational [Page 6] + +RFC 3753 Mobility Related Terminology June 2004 + + + Medium Access Protocol (MAC) + + A protocol for mediating access to, and possibly allocation of, + the physical communications medium. Nodes participating in the + medium access protocol can communicate only when they have + uncontested access to the medium, so that there will be no + interference. When the physical medium is a radio channel, the + MAC is the same as the Channel Access Protocol. + + Mobile network prefix + + A bit string that consists of some number of initial bits of an IP + address which identifies the entire mobile network within the + Internet topology. All nodes in a mobile network necessarily have + an address containing this prefix. + + Mobility factor + + The relative frequency of node movement, compared to the frequency + of application initiation. + + Multipoint relay (MPR) + + A node which is selected by its one-hop neighbor to re-transmit + all broadcast messages that it receives. The message must be new + and the time-to-live field of the message must be greater than + one. Multipoint relaying is a technique to reduce the number of + redundant re-transmissions while diffusing a broadcast message in + the network. + + Neighbor + + A "neighbor" is any other node to which data may be propagated + directly over the communications medium without relying on the + assistance of any other forwarding node. + + Neighborhood + + All the nodes which can receive data on the same link from one + node whenever it transmits data. + + Next hop + + A neighbor which has been selected to forward packets along the + way to a particular destination. + + + + + + +Manner & Kojo Informational [Page 7] + +RFC 3753 Mobility Related Terminology June 2004 + + + Payload + + The actual data within a packet, not including network protocol + headers which were not inserted by an application. Note that + payloads are different between layers: application data is the + payload of TCP, which are the payload of IP, which three are the + payload of link layer protocols etc. Thus, it is important to + identify the scope when talking about payloads. + + Prefix + + A bit string that consists of some number of initial bits of an + address. + + Routing table + + The table where forwarding nodes keep information (including next + hop) for various destinations. + + Route entry + + An entry for a specific destination (unicast or multicast) in the + routing table. + + Route establishment + + The process of determining a route between a source and a + destination. + + Route activation + + The process of putting a route into use after it has been + determined. + + Routing proxy + + A node that routes packets by overlays, e.g., by tunneling, + between communicating partners. The Home Agent and Foreign Agent + are examples of routing proxies, in that they receive packets + destined for the mobile node and tunnel them to the current + address of the mobile node. + + + + + + + + + + +Manner & Kojo Informational [Page 8] + +RFC 3753 Mobility Related Terminology June 2004 + + + Shannon's Law + + A statement defining the theoretical maximum rate at which error- + free digits can be transmitted over a bandwidth-limited channel in + the presence of noise. No practical error correction coding + system exists that can closely approach the theoretical + performance limit given by Shannon's law. + + Signal strength + + The detectable power of the signal carrying the data bits, as seen + by the receiver of the signal. + + Source route + + A source route from node A to node B is an ordered list of IP + addresses, starting with the IP address of node A and ending with + the IP address of the node B. Between A and B, the source route + includes an ordered list of intermediate hops between A and B, as + well as the interface index of the interface through which the + packet should be transmitted to reach the next hop. The list of + intermediate hops might not include all visited nodes, some hops + might be omitted for a reason or another. + + Spatial re-use + + Simultaneous use of channels with identical or close physical + characteristics, but located spatially far enough apart to avoid + interference (i.e., co-channel interference) + + System-wide broadcast + + Same as flooding, but used in contrast to local broadcast. + + Subnet + + A subnet is a logical group of connected network nodes. In IP + networks, nodes in a subnet share a common network mask (in IPV4) + or a network prefix (in IPv6). + + Topology (Network Topology) + + The interconnection structure of a network: which nodes are + directly connected to each other, and through which links they are + connected. Some simple topologies have been given names, such as + for instance 'bus topology', 'mesh topology', 'ring topology', + 'star topology' and 'tree topology'. + + + + +Manner & Kojo Informational [Page 9] + +RFC 3753 Mobility Related Terminology June 2004 + + + Triggered update + + A solicited route update transmitted by a router along a path to a + destination. + +3. Mobile Access Networks and Mobile Networks + + In order to support host mobility a set of nodes towards the network + edge may need to have specific functions. Such a set of nodes forms + a mobile access network that may or may not be part of the global + Internet. Figure 1 presents two examples of such access network + topologies. The figure depicts a reference architecture which + illustrates an IP network with components defined in this section. + + We intend to define the concept of the Access Network (AN) which may + also support enhanced mobility. It is possible that to support + routing and QoS for mobile nodes, existing routing protocols (e.g., + Open Shortest Path First (OSPF) [14]) may not be appropriate to + maintain forwarding information for these mobile nodes as they change + their points of attachment to the Access Network. These new + functions are implemented in routers with additional capabilities. + We can distinguish three types of Access Network components: Access + Routers (AR) which handle the last hop to the mobile, typically over + a wireless link; Access Network Gateways (ANG) which form the + boundary on the fixed network side and shield the fixed network from + the specialized routing protocols; and (optionally) other internal + Access Network Routers which may also be needed in some cases to + support the functions. The Access Network consists of the equipment + needed to support this specialized routing, i.e., AR or ANG. AR and + ANG may be the same physical nodes. + + In addition, we present a few basic terms on mobile networks, that + is, mobile network, mobile router (MR), and mobile network node + (MNN). More terminology for discussing mobile networks can be found + in [13]. A more thorough discussion of mobile networks can be found + in the working group documents of the NEMO Working Group. + + Note: this reference architecture is not well suited for people + dealing with Mobile Ad-hoc Networks (MANET). + + + + + + + + + + + + +Manner & Kojo Informational [Page 10] + +RFC 3753 Mobility Related Terminology June 2004 + + + | + | + --- ------ ------- | + --- | <--> | | -------| AR | -------------------| | | + | |--[] --- /------ \ /| ANG |--| + --- AP / \ / | | | + MH / \ / ------- | + (with wireless ___ / ------- | + device) | |---- | ANR | | + --- ------- | + AP / \ | + / \ ------- | + --- ------ / \| | | + | |-------| AR |---------------------| ANG |--| + --- ------ | | | + AP ------- | + | + Access Network (AN) 1 | + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -| + Access Network (AN) 2 | + | + | + --- ------ ------- | + --- | <--> | | -------| AR | -------------------| | | + | |--[] --- /------ /| ANG |--| + --- AP / / | | | + MH / / ------- | + (with wireless ___ / / | + device) | |---- / | + --- / | + AP / | + / | + | --- ------ ------- | + --- | | <->| |-------| AR |---------| ANR | | + | |-| [] --- \ ------ ------- | + --- | -----| AP \ / | + MNN |--i MR e \ / | + | ------ --- \ ------ / | + --- | (with | |-------| AR |------- | + | |-| wireless --- ------ | + --- | device) AP | + MNN 'i': MR ingress interface | + 'e': MR egress interface | + | + + Figure 1: Reference Network Architecture + + + + + +Manner & Kojo Informational [Page 11] + +RFC 3753 Mobility Related Terminology June 2004 + + + Mobile Node (MN) + + An IP node capable of changing its point of attachment to the + network. A Mobile Node may either be a Mobile Host (no forwarding + functionality) or a Mobile Router (forwarding functionality). + + Mobile Host (MH) + + A mobile node that is an end host and not a router. A Mobile Host + is capable of sending and receiving packets, that is, being a + source or destination of traffic, but not a forwarder of it. + + Fixed Node (FN) + + A node, either a host or a router, unable to change its point of + attachment to the network and its IP address without breaking open + sessions. + + Mobile network + + An entire network, moving as a unit, which dynamically changes its + point of attachment to the Internet and thus its reachability in + the topology. The mobile network is composed of one or more IP- + subnets and is connected to the global Internet via one or more + Mobile Routers (MR). The internal configuration of the mobile + network is assumed to be relatively stable with respect to the MR. + + Mobile Router (MR) + + A router capable of changing its point of attachment to the + network, moving from one link to another link. The MR is capable + of forwarding packets between two or more interfaces, and possibly + running a dynamic routing protocol modifying the state by which it + does packet forwarding. + + A MR acting as a gateway between an entire mobile network and the + rest of the Internet has one or more egress interface(s) and one + or more ingress interface(s). Packets forwarded upstream to the + rest of the Internet are transmitted through one of the MR's + egress interface; packets forwarded downstream to the mobile + network are transmitted through one of the MR's ingress interface. + + Ingress interface + + The interface of a MR attached to a link inside the mobile + network. + + + + + +Manner & Kojo Informational [Page 12] + +RFC 3753 Mobility Related Terminology June 2004 + + + Egress interface + + The interface of a MR attached to the home link if the MR is at + home, or attached to a foreign link if the MR is in a foreign + network. + + Mobile Network Node (MNN) + + Any node (host or router) located within a mobile network, either + permanently or temporarily. A Mobile Network Node may either be a + mobile node or a fixed node. + + Access Link (AL) + + A last-hop link between a Mobile Node and an Access Point. That + is, a facility or medium over which an Access Point and the Mobile + Node can communicate at the link layer, i.e., the layer + immediately below IP. + + Access Point (AP) + + An Access Point is a layer 2 device which is connected to one or + more Access Routers and offers the wireless link connection to the + Mobile Node. Access Points are sometimes called base stations or + access point transceivers. An Access Point may be a separate + entity or co-located with an Access Router. + + Radio Cell + + The geographical area within which an Access Point provides radio + coverage, i.e., where radio communication between a Mobile Node + and the specific Access Point is possible. + + Access Network Router (ANR) + + An IP router in the Access Network. An Access Network Router may + include Access Network specific functionalities, for example, + related to mobility and/or QoS. This is to distinguish between + ordinary routers and routers that have Access Network-related + special functionality. + + + + + + + + + + + +Manner & Kojo Informational [Page 13] + +RFC 3753 Mobility Related Terminology June 2004 + + + Access Router (AR) + + An Access Network Router residing on the edge of an Access Network + and connected to one or more Access Points. The Access Points may + be of different technology. An Access Router offers IP + connectivity to Mobile Nodes, acting as a default router to the + Mobile Nodes it is currently serving. The Access Router may + include intelligence beyond a simple forwarding service offered by + ordinary IP routers. + + Access Network Gateway (ANG) + + An Access Network Router that separates an Access Network from + other IP networks, much in the same way as an ordinary gateway + router. The Access Network Gateway looks to the other IP networks + like a standard IP router. In a small network, an ANG may also + offer the services of an AR, namely offer the IP connectivity to + the mobile nodes. + + Access Network (AN) + + An IP network which includes one or more Access Network Routers. + + Administrative Domain (AD) + + A collection of networks under the same administrative control and + grouped together for administrative purposes [5]. + + Serving Access Router (SAR) + + The Access Router currently offering the connectivity to the MN. + This is usually the point of departure for the MN as it makes its + way towards a new Access Router (at which time the Serving Access + Router takes the role of the Previous Access Router). There may + be several Serving Access Routers serving the Mobile Node at the + same time. + + New Access Router (NAR) + + The Access Router that offers connectivity to the Mobile Node + after a handover. + + + + + + + + + + +Manner & Kojo Informational [Page 14] + +RFC 3753 Mobility Related Terminology June 2004 + + + Previous Access Router (PAR) + + An Access Router that offered connectivity to the Mobile Node + prior to a handover. This is the Serving Access Router that will + cease or has ceased to offer connectivity to the Mobile Node. + Often also called Old Access Router (OAR). + + Candidate Access Router (CAR) + + An Access Router to which the Mobile Node may do a handoff. See + Section 4.8. + +4. Handover Terminology + + These terms refer to different perspectives and approaches to + supporting different aspects of mobility. Distinctions can be made + according to the scope, range overlap, performance characteristics, + diversity characteristics, state transitions, mobility types, and + control modes of handover techniques. + + Roaming + + An operator-based term involving formal agreements between + operators that allows a mobile to get connectivity from a foreign + network. Roaming (a particular aspect of user mobility) includes, + for example, the functionality by which users can communicate + their identity to the local AN so that inter-AN agreements can be + activated and service and applications in the MN's home network + can be made available to the user locally. + + Handover + + The process by which an active MN (in the Active State, see + section 4.6) changes its point of attachment to the network, or + when such a change is attempted. The access network may provide + features to minimize the interruption to sessions in progress. + Also called handoff. + + There are different types of handover classified according to + different aspects involved in the handover. Some of this + terminology follows the description in [4]. + + + + + + + + + + +Manner & Kojo Informational [Page 15] + +RFC 3753 Mobility Related Terminology June 2004 + + +4.1. Scope of Handover + + Layer 2 handover + + A handover where the MN changes APs (or some other aspect of the + radio channel) connected to the same AR's interface. This type of + handover is transparent to the routing at the IP layer (or it + appears simply as a link layer reconfiguration without any + mobility implications). + + Intra-AR handover + + A handover which changes the AR's network interface to the mobile. + That is, the Serving AR remains the same but routing changes + internal to the AR take place. + + Intra-AN handover + + A handover where the MN changes ARs inside the same AN. Such a + handover is not necessarily visible outside the AN. In case the + ANG serving the MN changes, this handover is seen outside the AN + due to a change in the routing paths. Note that the ANG may + change for only some of the MN's data flows. + + Inter-AN handover + + A handover where the MN moves to a new AN. This requires support + for macro mobility. Note that this would have to involve the + assignment of a new IP access address (e.g., a new care-of + address) to the MN. + + Intra-technology handover + + A handover between equipment of the same technology. + + Inter-technology handover + + A handover between equipment of different technologies. + + Horizontal handover + + This involves MNs moving between access points of the same type + (in terms of coverage, data rate and mobility), such as, UMTS to + UMTS, or WLAN to WLAN. + + + + + + + +Manner & Kojo Informational [Page 16] + +RFC 3753 Mobility Related Terminology June 2004 + + + Vertical handover + + This involves MNs moving between access points of different type, + such as, UMTS to WLAN. + + Note that the difference between a horizontal and vertical handover + is vague. For example, a handover from an AP with 802.11b WLAN link + to an AP with 802.11g WLAN link may be considered as either a + vertical or a horizontal handover, depending on an individual's point + of view. + + Note also that the IP layer sees network interfaces and IP addresses, + rather than specific technologies used by those interfaces. Thus, + horizontal and vertical handovers may or may not be noticed at the IP + layer. Usually a handover can be noticed if the IP address assigned + to the interface changes, the network interface itself changes (which + can also change the IP address), or there is a link outage, for + example, when the mobile node moves out of coverage for a while. For + example, in a GPRS network a horizontal handover happens usually + unnoticed by the IP layer. Similarly, a WLAN horizontal handover may + be noticed if the IP address of the interface changes. On the other + hand, vertical handovers often change the network interface and are, + therefore, noticed on the IP layer. Still, some specific network + cards may be able to switch between access technologies (e.g., GPRS + to UMTS) without changing the network interface. Moreover, either of + the two handovers may or may not result in changing the AR. For + example, an AR could control WLAN and Bluetooth access points, and + the mobile node could do horizontal and vertical handovers under the + same AR without changing its IP address or even the network + interface. + +4.2. Handover Control + + A handover must be one of the following two types (a): + + Mobile-initiated handover + + The MN is the one that makes the initial decision to initiate + the handover. + + Network-initiated handover + + The network makes the initial decision to initiate the + handover. + + + + + + + +Manner & Kojo Informational [Page 17] + +RFC 3753 Mobility Related Terminology June 2004 + + + A handover is also one of the following two types (b): + + Mobile-controlled handover + + The MN has the primary control over the handover process. + + Network-controlled handover + + The network has the primary control over the handover process. + + A handover decision usually involves some sort of measurements about + when and where to handover to. Therefore, a handover is also either + of these three types (c): + + Mobile-assisted handover + + Information and measurement from the MN are used by the AR to + decide on the execution of a handover. + + Network-assisted handover + + A handover where the AN collects information that can be used + by the MN in a handover decision. + + Unassisted handover + + A handover where no assistance is provided by the MN or the AR + to each other. + + Note that it is possible that the MN and the AR both do measurements + and decide on the handover. + + A handover is also one of the following two types (d): + + Push handover + + A handover either initiated by the PAR, or where the MN + initiates a handover via the PAR. + + Pull handover + + A handover either initiated by the NAR, or where the MN + initiates a handover via the NAR. + + + + + + + + +Manner & Kojo Informational [Page 18] + +RFC 3753 Mobility Related Terminology June 2004 + + + The handover is also either proactive or reactive (e): + + Planned handover + + A proactive (expected) handover where some signaling can be + done in advance of the MN getting connected to the new AR, + e.g., building a temporary tunnel from the previous AR to the + new AR. + + Unplanned handover + + A reactive (unexpected) handover where no signaling is done in + advance of the MN's move from the previous AR to the new AR. + + The five handover types (a-e) are mostly independent, and every + handover should be classifiable according to each of these types. + +4.3. Simultaneous connectivity to Access Routers + + Make-before-break (MBB) + + During a MBB handover the MN makes the new connection before the + old one is broken. Thus, the MN can communicate simultaneously + with the old and new AR during the handover. This should not be + confused with "soft handover" which relies on macro diversity, + described in Section 4.5. + + Break-before-make (BBM) + + During a BBM handover the MN breaks the old connection before the + new connection is made. Thus, the MN cannot communicate + simultaneously with the old and the new AR. + +4.4. Performance and Functional Aspects + + Handover latency + + Handover latency is the difference between the time a MN is last + able to send and/or receive an IP packet by way of the PAR, and + the time the MN is able to send and/or receive an IP packet + through the NAR. Adapted from [4]. + + Smooth handover + + A handover that aims primarily to minimize packet loss, with no + explicit concern for additional delays in packet forwarding. + + + + + +Manner & Kojo Informational [Page 19] + +RFC 3753 Mobility Related Terminology June 2004 + + + Fast handover + + A handover that aims primarily to minimize handover latency, with + no explicit interest in packet loss. + + Seamless handover + + A handover in which there is no change in service capability, + security, or quality. In practice, some degradation in service is + to be expected. The definition of a seamless handover in the + practical case should be that other protocols, applications, or + end users do not detect any change in service capability, security + or quality, which would have a bearing on their (normal) + operation. As a consequence, what would be a seamless handover + for one less demanding application might not be seamless for + another more demanding application. See [7] for more discussion + on the topic. + + Throughput + + The amount of data from a source to a destination processed by the + protocol for which throughput is to be measured, for instance, IP, + TCP, or the MAC protocol. The throughput differs between protocol + layers. + + Goodput + + The total bandwidth used, less the volume of control messages, + protocol overhead from the data packets, and packets dropped due + to CRC errors. + + Pathloss + + A reduction in signal strength caused by traversing the physical + medium constituting the link. + + Hidden-terminal problem + + The problem whereby a transmitting node can fail in its attempt to + transmit data because of destructive interference which is only + detectable at the receiving node, not the transmitting node. + + Exposed terminal problem + + The problem whereby a transmitting node A prevents another node B + from transmitting, although node B could have safely transmitted + to anyone else but the transmitting node A. + + + + +Manner & Kojo Informational [Page 20] + +RFC 3753 Mobility Related Terminology June 2004 + + +4.5. Micro Diversity, Macro Diversity, and IP Diversity + + Certain air interfaces (e.g., the Universal Mobile Telephone System + (UMTS) Terrestrial Radio Access Network (UTRAN) running in Frequency + Division Duplex (FDD) mode) require or at least support macro + diversity combining. Essentially, this refers to the fact that a + single MN is able to send and receive over two independent radio + channels ('diversity branches') at the same time; the information + received over different branches is compared and that from the better + branch passed to the upper layers. This can be used both to improve + overall performance, and to provide a seamless type of handover at + layer 2, since a new branch can be added before the old is deleted. + See also [6]. + + It is necessary to differentiate between combining/diversity that + occurs at the physical and radio link layers, where the relevant unit + of data is the radio frame, and that which occurs at layer 3, the + network layer, where what is considered is the IP packet itself. + + In the following definitions micro- and macro diversity refer to + protocol layers below the network layer, and IP diversity refers to + the network layer. + + Micro diversity + + For example, two antennas on the same transmitter send the same + signal to a receiver over a slightly different path to overcome + fading. + + Macro diversity + + Duplicating or combining actions taking place over multiple APs, + possibly attached to different ARs. This may require support from + the network layer to move the radio frames between the base + stations and a central combining point. + + IP diversity + + Refers to the process of duplicating IP packets and sending them + to the receiver through more than one point of attachment. This + is semantically allowed by IP because it does not guarantee packet + uniqueness, and higher level protocols are assumed to eliminate + duplicates whenever that is important for the application. + + + + + + + + +Manner & Kojo Informational [Page 21] + +RFC 3753 Mobility Related Terminology June 2004 + + +4.6. Paging, and Mobile Node States and Modes + + Mobile systems may employ the use of MN states in order to operate + more efficiently without degrading the performance of the system. + The term 'mode' is also common and means the same as 'state'. + + A MN is always in one of the following three states: + + Active state + + When the AN knows the MN's SAR and the MN can send and receive IP + packets. The access link may not be active, but the radio layer + is able to establish one without assistance from the network + layer. The MN has an IP address assigned. + + Dormant state + + A state in which the mobile restricts its ability to receive + normal IP traffic by reducing its monitoring of radio channels. + The AN knows the MN's Paging Area, but the MN has no SAR and so + packets cannot be delivered to the MN without the AN initiating + paging. Often also called Idle state. + + Time-slotted dormant mode + + A dormant mode implementation in which the mobile alternates + between periods of not listening for any radio traffic and + listening for traffic. Time-slotted dormant mode + implementations are typically synchronized with the network so + the network can deliver paging messages to the mobile during + listening periods. + + Inactive state + + the MN is in neither the Active nor Dormant State. The MN is no + longer listening for any packets, not even periodically, and not + sending packets. The MN may be in a powered off state, it may + have shut down all interfaces to drastically conserve power, or it + may be out of range of a radio access point. The MN does not + necessarily have an IP access address from the AN. + + Note: in fact, as well as the MN being in one of these three states, + the AN also stores which state it believes the MN is in. Normally + these are consistent; the definitions above assume so. + + Here are some additional definitions for paging, taking into account + the above state definitions. + + + + +Manner & Kojo Informational [Page 22] + +RFC 3753 Mobility Related Terminology June 2004 + + + Paging + + A procedure initiated by the Access Network to move a Dormant MN + into the Active State. As a result of paging, the MN establishes + a SAR and the IP routes are set up. + + Location updating + + A procedure initiated by the MN, by which it informs the AN that + it has moved into a new paging area. + + Paging area + + A part of the Access Network, typically containing a number of + ARs/APs, which corresponds to some geographical area. The AN + keeps and updates a list of all the Dormant MNs present in the + area. If the MN is within the radio coverage of the area it will + be able to receive paging messages sent within that Paging Area. + + Paging area registrations + + Signaling from a dormant mode mobile node to the network, by which + it establishes its presence in a new paging area. Paging Area + Registrations thus enable the network to maintain a rough idea of + where the mobile is located. + + Paging channel + + A radio channel dedicated to signaling dormant mode mobiles for + paging purposes. By current practice, the paging channel carries + only control traffic necessary for the radio link, although some + paging protocols have provision for carrying arbitrary traffic + (and thus could potentially be used to carry IP). + + Traffic channel + + The radio channel on which IP traffic to an active mobile is + typically sent. This channel is used by a mobile that is actively + sending and receiving IP traffic, and is not continuously active + in a dormant mode mobile. For some radio link protocols, this may + be the only channel available. + + + + + + + + + + +Manner & Kojo Informational [Page 23] + +RFC 3753 Mobility Related Terminology June 2004 + + +4.7. Context Transfer + + Context + + The information on the current state of a routing-related service + required to re-establish the routing-related service on a new + subnet without having to perform the entire protocol exchange with + the MN from scratch. + + Feature context + + The collection of information representing the context for a given + feature. The full context associated with a MN is the collection + of one or more feature contexts. + + Context transfer + + The movement of context from one router or other network entity to + another as a means of re-establishing routing-related services on + a new subnet or collection of subnets. + + Routing-related service + + A modification to the default routing treatment of packets to and + from the MN. Initially establishing routing-related services + usually requires a protocol exchange with the MN. An example of a + routing-related service is header compression. The service may + also be indirectly related to routing, for example, security. + Security may not affect the forwarding decision of all + intermediate routers, but a packet may be dropped if it fails a + security check (can't be encrypted, authentication failed, etc.). + Dropping the packet is basically a routing decision. + +4.8. Candidate Access Router Discovery + + Capability of an AR + + A characteristic of the service offered by an AR that may be of + interest to an MN when the AR is being considered as a handoff + candidate. + + Candidate AR (CAR) + + An AR to which MN has a choice of performing IP-level handoff. + This means that MN has the right radio interface to connect to an + AP that is served by this AR, as well as the coverage of this AR + overlaps with that of the AR to which MN is currently attached. + + + + +Manner & Kojo Informational [Page 24] + +RFC 3753 Mobility Related Terminology June 2004 + + + Target AR (TAR) + + An AR with which the procedures for the MN's IP-level handoff are + initiated. TAR is selected after running a TAR Selection + Algorithm that takes into account the capabilities of CARs, + preferences of MN and any local policies. + +4.9. Types of Mobility + + We can differentiate between host and network mobility, and various + types of network mobility. Terminology related more to applications + such as the Session Initiation Protocol, such as personal mobility, + is out of scope for this document. + + Host mobility support + + Refers to the function of allowing a mobile node to change its + point of attachment to the network, without interrupting IP + packet delivery to/from that node. There may be different sub- + functions depending on what the current level of service is + being provided; in particular, support for host mobility + usually implies active and dormant modes of operation, + depending on whether the node has any current sessions or not. + Access Network procedures are required to keep track of the + current point of attachment of all the MNs or establish it at + will. Accurate location and routing procedures are required in + order to maintain the integrity of the communication. Host + mobility is often called 'terminal mobility'. + + Network mobility support + + Refers to the function of allowing an entire network to change + its point of attachment to the Internet, and, thus, its + reachability in the topology, without interrupting IP packet + delivery to/from that mobile network. + + Two subcategories of mobility can be identified within both host + mobility and network mobility: + + Global mobility + + Same as Macro mobility. + + Local mobility + + Same as Micro mobility. + + + + + +Manner & Kojo Informational [Page 25] + +RFC 3753 Mobility Related Terminology June 2004 + + + Macro mobility + + Mobility over a large area. This includes mobility support and + associated address registration procedures that are needed when + a MN moves between IP domains. Inter-AN handovers typically + involve macro-mobility protocols. Mobile-IP can be seen as a + means to provide macro mobility. + + Micro mobility + + Mobility over a small area. Usually this means mobility within + an IP domain with an emphasis on support for active mode using + handover, although it may include idle mode procedures also. + Micro-mobility protocols exploit the locality of movement by + confining movement related changes and signaling to the access + network. + + Local mobility management + + Local mobility management (LMM) is a generic term for protocols + dealing with IP mobility management confined within the access + network. LMM messages are not routed outside the access + network, although a handover may trigger Mobile IP messages to + be sent to correspondent nodes and home agents. + +5. Specific Terminology for Mobile Ad-Hoc Networking + + Cluster + + A group of nodes located within close physical proximity, + typically all within range of one another, which can be grouped + together for the purpose of limiting the production and + propagation of routing information. + + Cluster head + + A cluster head is a node (often elected in the cluster formation + process) that has complete knowledge about group membership and + link state information in the cluster. Each cluster should have + one and only one cluster head. + + Cluster member + + All nodes within a cluster except the cluster head are called + members of that cluster. + + + + + + +Manner & Kojo Informational [Page 26] + +RFC 3753 Mobility Related Terminology June 2004 + + + Convergence + + The process of approaching a state of equilibrium in which all + nodes in the network agree on a consistent collection of state + about the topology of the network, and in which no further control + messages are needed to establish the consistency of the network + topology. + + Convergence time + + The time which is required for a network to reach convergence + after an event (typically, the movement of a mobile node) which + changes the network topology. + + Laydown + + The relative physical location of the nodes within the ad hoc + network. + + Pathloss matrix + + A matrix of coefficients describing the pathloss between any two + nodes in an ad hoc network. When the links are asymmetric, the + matrix is also asymmetric. + + Scenario + + The tuple <laydown, pathloss matrix, mobility factor, traffic> + characterizing a class of ad hoc networks. + +6. Security-related Terminology + + This section includes terminology commonly used around mobile and + wireless networking. Only a mobility-related subset of the entire + security terminology is presented. + + Authorization-enabling extension + + An authentication which makes a (registration) message + acceptable to the ultimate recipient of the registration + message. An authorization-enabling extension must contain an + SPI (see below) [10]. + + Mobility security association + + A collection of security contexts, between a pair of nodes, + which may be applied to mobility-related protocol messages + exchanged between them. In Mobile IP, each context indicates + + + +Manner & Kojo Informational [Page 27] + +RFC 3753 Mobility Related Terminology June 2004 + + + an authentication algorithm and mode, a secret (a shared key, + or appropriate public/private key pair), and a style of replay + protection in use. Mobility security associations may be + stored separately from the node's IPsec Security Policy + Database (SPD) [10]. + + Registration key + + A key used in the Mobility Security Association between a + mobile node and a foreign agent. A registration key is + typically only used once or a very few times, and only for the + purposes of verifying a small volume of Authentication data + [12]. + + Security context + + A security context between two nodes defines the manner in + which two nodes choose to mutually authenticate each other, and + indicates an authentication algorithm and mode. + + Security Parameter Index (SPI) + + An index identifying a security context between a pair of + routers among the contexts available in the mobility security + association. + + The Mobile IPv6 specification includes more security terminology + related to MIPv6 bindings [9]. Terminology about the MIP + challenge/response mechanism can be found in [11]. + +7. Security Considerations + + This document presents only terminology. There are no security + issues in this document. + +8. Contributors + + This document was initially based on the work of Tapio Suihko, Phil + Eardley, Dave Wisely, Robert Hancock, Nikos Georganopoulos, Markku + Kojo, and Jukka Manner. + + Charles Perkins has provided input terminology related to ad-hoc + networks. + + Thierry Ernst has provided the terminology for discussing mobile + networks. + + + + + +Manner & Kojo Informational [Page 28] + +RFC 3753 Mobility Related Terminology June 2004 + + + Henrik Levkowetz did a final check of the definitions in revision -05 + and suggested a number of changes. + +9. Acknowledgments + + This work has been partially performed in the framework of the IST + project IST-2000-28584 MIND, which is partly funded by the European + Union. Some of the authors would like to acknowledge the help of + their colleagues in preparing this document. + + Randy Presuhn did a very thorough and helpful review of the -02 + version of the terminology. + + Some definitions of terminology have been adapted from [1], [2], [3], + [4], [7], [8], [9] and [10]. + +10. Informative References + + [1] Blair, D., Tweedly, A., Thomas, M., Trostle, J. and M. Ramalho, + "Realtime Mobile IPv6 Framework", Work in Progress. + + [2] Calhoun, P., Montenegro, G. and C. Perkins, "Mobile IP + Regionalized Tunnel Management", Work in Progress. + + [3] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) + Specification", RFC 2460, December 1998. + + [4] Koodli, R., Ed., "Fast Handovers for Mobile IPv6", Work in + Progress. + + [5] Yavatkar, R., Pendarakis, D. and R. Guerin, "A Framework for + Policy-based Admission Control", RFC 2753, January 2000. + + [6] Kempf, J., McCann, P. and P. Roberts, "IP Mobility and the CDMA + Radio Access Network: Applicability Statement for Soft + Handoff", Work in Progress. + + [7] Kempf, J., Ed., "Problem Description: Reasons For Performing + Context Transfers Between Nodes in an IP Access Network", RFC + 3374, September 2002. + + [8] Trossen, D., Krishnamurthi, G., Chaskar, H. and J. Kempf, + "Issues in candidate access router discovery for seamless IP- + level handoffs", Work in Progress. + + [9] Johnson, D., Perkins, C. and J. Arkko, "Mobility Support in + IPv6", RFC 3775, June 2004. + + + + +Manner & Kojo Informational [Page 29] + +RFC 3753 Mobility Related Terminology June 2004 + + + [10] Perkins, C., Ed., "IP Mobility Support for IPv4", RFC 3344, + August 2002. + + [11] Perkins, C., Calhoun, P. and J. Bharatia, "Mobile IPv4 + Challenge/Response Extensions (revised)", Work in Progress. + + [12] Perkins, C. and P. Calhoun, "AAA Registration Keys for Mobile + IP", Work in Progress. + + [13] Ernst, T. and H. Lach, "Network Mobility Support Terminology", + Work in Progress. + + [14] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Manner & Kojo Informational [Page 30] + +RFC 3753 Mobility Related Terminology June 2004 + + +11. Appendix A - Index of Terms + + AD ............................................................. 14 + AL ............................................................. 13 + AN ............................................................. 14 + ANG ............................................................ 14 + ANR ............................................................ 13 + AP ............................................................. 13 + AR ............................................................. 14 + Access Link .................................................... 13 + Access Network ................................................. 14 + Access Network Gateway ......................................... 14 + Access Network Router .......................................... 13 + Access Point ................................................... 13 + Access Router .................................................. 14 + Active state ................................................... 22 + Administrative Domain .......................................... 14 + Asymmetric link ................................................. 5 + Authorization-enabling extension ............................... 27 + BBM ............................................................ 19 + BU .............................................................. 3 + Bandwidth ....................................................... 2 + Bandwidth utilization ........................................... 2 + Beacon .......................................................... 3 + Binding Update .................................................. 3 + Break-before-make .............................................. 19 + CAR ............................................................ 15 + CAR ............................................................ 24 + Candidate AR ................................................... 24 + Candidate Access Router ........................................ 15 + Capability of an AR ............................................ 24 + Care-of-Address ................................................. 3 + Channel ......................................................... 3 + Channel access protocol ......................................... 3 + Channel capacity ................................................ 3 + Cluster ........................................................ 26 + Cluster head ................................................... 26 + Cluster member ................................................. 26 + CoA ............................................................. 3 + Context ........................................................ 24 + Context transfer ............................................... 24 + Control message ................................................. 4 + Convergence .................................................... 27 + Convergence time ............................................... 27 + Distance vector ................................................. 4 + Dormant state .................................................. 22 + Egress interface ............................................... 13 + Exposed terminal problem ....................................... 20 + + + +Manner & Kojo Informational [Page 31] + +RFC 3753 Mobility Related Terminology June 2004 + + + FN ............................................................. 12 + Fairness ........................................................ 4 + Fast handover .................................................. 20 + Feature context ................................................ 24 + Fixed Node ..................................................... 12 + Flooding ........................................................ 4 + Foreign subnet prefix ........................................... 4 + Forwarding node ................................................. 4 + Global mobility ................................................ 25 + Goodput ........................................................ 20 + HA .............................................................. 5 + Handoff ........................................................ 15 + Handover ....................................................... 15 + Handover latency ............................................... 19 + Hidden-terminal problem ........................................ 20 + HoA ............................................................. 4 + Home Address .................................................... 4 + Home Agent ...................................................... 5 + Home subnet prefix .............................................. 5 + Horizontal Handover ............................................ 16 + Host mobility support .......................................... 25 + IP access address ............................................... 5 + IP diversity ................................................... 21 + Inactive state ................................................. 22 + Ingress interface .............................................. 12 + Inter-AN handover .............................................. 16 + Inter-technology handover ...................................... 16 + Interface ....................................................... 5 + Intra-AN handover .............................................. 16 + Intra-AR handover .............................................. 16 + Intra-technology handover ...................................... 16 + L2 Trigger ...................................................... 6 + Laydown ........................................................ 27 + Layer 2 handover ............................................... 16 + Link ............................................................ 5 + Link establishment .............................................. 6 + Link state ...................................................... 6 + Link-layer trigger .............................................. 6 + Link-level acknowledgment ....................................... 6 + Local broadcast ................................................. 6 + Local mobility ................................................. 25 + Local mobility management ...................................... 26 + Location updating .............................................. 23 + Loop-free ....................................................... 6 + MAC ............................................................. 7 + MBB ............................................................ 19 + MH ............................................................. 12 + MN ............................................................. 12 + + + +Manner & Kojo Informational [Page 32] + +RFC 3753 Mobility Related Terminology June 2004 + + + MNN ............................................................ 13 + MPR ............................................................. 7 + MR ............................................................. 12 + Macro diversity ................................................ 21 + Macro mobility ................................................. 26 + Make-before-break .............................................. 19 + Medium Access Protocol .......................................... 7 + Micro diversity ................................................ 21 + Micro mobility ................................................. 26 + Mobile Host .................................................... 12 + Mobile Network Node ............................................ 13 + Mobile Node .................................................... 12 + Mobile Router .................................................. 12 + Mobile network ................................................. 12 + Mobile network prefix ........................................... 7 + Mobile-assisted handover ....................................... 18 + Mobile-controlled handover ..................................... 18 + Mobile-initiated handover ...................................... 17 + Mobility factor ................................................. 7 + Mobility security association .................................. 27 + Multipoint relay ................................................ 7 + NAR ............................................................ 14 + Neighbor ........................................................ 7 + Neighborhood .................................................... 7 + Network mobility support ....................................... 25 + Network-assisted handover ...................................... 18 + Network-controlled handover .................................... 18 + Network-initiated handover ..................................... 17 + New Access Router .............................................. 14 + Next hop ........................................................ 7 + PAR ............................................................ 15 + Paging ......................................................... 23 + Paging area .................................................... 23 + Paging area registrations ...................................... 23 + Paging channel ................................................. 23 + Pathloss ....................................................... 20 + Pathloss matrix ................................................ 27 + Payload ......................................................... 8 + Planned handover ............................................... 19 + Prefix .......................................................... 8 + Previous Access Router ......................................... 15 + Pull handover .................................................. 18 + Push handover .................................................. 18 + Radio Cell ..................................................... 13 + Registration key ............................................... 28 + Roaming ........................................................ 15 + Route activation ................................................ 8 + Route entry ..................................................... 8 + + + +Manner & Kojo Informational [Page 33] + +RFC 3753 Mobility Related Terminology June 2004 + + + Route establishment ............................................. 8 + Routing table ................................................... 8 + Routing proxy ................................................... 8 + Routing-related service ........................................ 24 + SAR ............................................................ 14 + SPI ............................................................ 28 + Scenario ....................................................... 27 + Seamless handover .............................................. 19 + Security Parameter Index ....................................... 28 + Security context ............................................... 28 + Serving Access Router .......................................... 14 + Shannon's Law ................................................... 9 + Signal strength ................................................. 9 + Smooth handover ................................................ 19 + Source route .................................................... 9 + Spatial re-use .................................................. 9 + Subnet .......................................................... 9 + System-wide broadcast ........................................... 9 + TAR ............................................................ 25 + Target AR ...................................................... 25 + Throughput ..................................................... 20 + Time-slotted dormant mode ...................................... 22 + Topology ........................................................ 9 + Traffic channel ................................................ 23 + Triggered update ................................................10 + Unassisted handover ............................................ 18 + Unplanned handover ............................................. 19 + Vertical handover .............................................. 17 + + + + + + + + + + + + + + + + + + + + + + + +Manner & Kojo Informational [Page 34] + +RFC 3753 Mobility Related Terminology June 2004 + + +12. Authors' Addresses + + Jukka Manner + Department of Computer Science + University of Helsinki + P.O. Box 26 (Teollisuuskatu 23) + FIN-00014 HELSINKI + Finland + + Phone: +358-9-191-44210 + Fax: +358-9-191-44441 + EMail: jmanner@cs.helsinki.fi + + + Markku Kojo + Department of Computer Science + University of Helsinki + P.O. Box 26 (Teollisuuskatu 23) + FIN-00014 HELSINKI + Finland + + Phone: +358-9-191-44179 + Fax: +358-9-191-44441 + EMail: kojo@cs.helsinki.fi + + + + + + + + + + + + + + + + + + + + + + + + + + + +Manner & Kojo Informational [Page 35] + +RFC 3753 Mobility Related Terminology June 2004 + + +13. Full Copyright Statement + + Copyright (C) The Internet Society (2004). This document is subject + to the rights, licenses and restrictions contained in BCP 78, and + except as set forth therein, the authors retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE + REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE + INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF + THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED + WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed + to pertain to the implementation or use of the technology + described in this document or the extent to which any license + under such rights might or might not be available; nor does it + represent that it has made any independent effort to identify any + such rights. 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