--- 1/draft-ietf-dmm-ondemand-mobility-02.txt 2016-05-03 05:16:04.450297425 -0700 +++ 2/draft-ietf-dmm-ondemand-mobility-03.txt 2016-05-03 05:16:04.474298027 -0700 @@ -1,23 +1,23 @@ DMM Working Group A. Yegin Internet-Draft Unaffiliated Intended status: Standards Track K. Kweon -Expires: August 21, 2016 J. Lee +Expires: November 4, 2016 J. Lee J. Park Samsung D. Moses Intel - February 18, 2016 + May 3, 2016 On Demand Mobility Management - draft-ietf-dmm-ondemand-mobility-02 + draft-ietf-dmm-ondemand-mobility-03 Abstract Applications differ with respect to whether they need IP session continuity and/or IP address reachability. The network providing the same type of service to any mobile host and any application running on the host yields inefficiencies. This document describes a solution for taking the application needs into account in selectively providing IP session continuity and IP address reachability on a per- socket basis. @@ -30,21 +30,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on August 21, 2016. + This Internet-Draft will expire on November 4, 2016. Copyright Notice Copyright (c) 2016 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 @@ -59,27 +59,27 @@ 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4 3. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1. Types of IP Addresses . . . . . . . . . . . . . . . . . . 4 3.2. Granularity of Selection . . . . . . . . . . . . . . . . 5 3.3. On Demand Nature . . . . . . . . . . . . . . . . . . . . 5 3.4. Conveying the Selection . . . . . . . . . . . . . . . . . 6 4. Backwards Compatibility Considerations . . . . . . . . . . . 8 4.1. Applications . . . . . . . . . . . . . . . . . . . . . . 8 4.2. IP Stack in the Mobile Host . . . . . . . . . . . . . . . 8 - 4.3. Network Infrastructure . . . . . . . . . . . . . . . . . 8 + 4.3. Network Infrastructure . . . . . . . . . . . . . . . . . 9 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 8.1. Normative References . . . . . . . . . . . . . . . . . . 9 - 8.2. Informative References . . . . . . . . . . . . . . . . . 9 + 8.2. Informative References . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 1. Introduction In the context of Mobile IP [RFC5563][RFC6275][RFC5213][RFC5944], following two attributes are defined for the IP service provided to the mobile hosts: IP session continuity: The ability to maintain an ongoing IP session by keeping the same local end-point IP address throughout the session @@ -155,96 +155,109 @@ 3. Solution 3.1. Types of IP Addresses Three types of IP addresses are defined with respect to the mobility management. - Fixed IP Address - This is what standard Mobile IP provides with a Home Address (HoA). - The mobile host is configures a HoA from a centrally-located Home - Network. Both IP session continuity and IP address reachability are - provided to the mobile host with the help of a router in the Home - Network (Home Agent, HA). This router acts as an anchor for the IP - address of the mobile host. + A Fixed IP address is an address assigned to the mobile host by the + network with a guarantee to be valid for a very long time, regardless + of whether it is being used in any packets to/from the mobile host, + or whether or not the mobile host is connected to the network, or + whether it moves from one LAN to another (with a different IP prefix) + while it is connected. - - Sustained IP Address + Fixed IP address are required by applications that need both IP + session continuity and IP address reachability. - This type of IP address provides IP session continuity but not IP - address reachability. It is achieved by ensuring that the IP address - used at the beginning of the session remains usable despite the - movement of the mobile host. The IP address may change after the - termination of the IP session(s), therefore it does not exhibit - persistence. + - Session-lasting IP Address - A sustained IP address may be configured and maintained by using - access network anchoring, corresponding network anchoring, or some - other solution. + A session-lasting IP address is an address assigned to the mobile + host by the network with a guarantee to be valid through-out the IP + session(s) for which it was requested. It is guaranteed to be valid + even after the mobile host had moved from one LAN to another (with a + different IP prefix). - - Nomadic IP Address + Session-lasting IP addresses are required by applications that need + IP session continuity but do not need IP address reachability. + + - Non-persistent IP Address This type of IP address provides neither IP session continuity nor IP address reachability. The IP address is obtained from the serving IP gateway and it is not maintained across gateway changes. In other words, the IP address may be released and replaced by a new IP address when the IP gateway changes due to the movement of the mobile host. Applications running as servers at a published IP address require a Fixed IP Address. Long-standing applications (e.g., an SSH session) - may also require this type of address. Those applications could use - a Sustained IP Address, but that can produce sub-optimal results if - the mobile host ends up far from the anchor gateway. Enterprise - applications that connect to an enterprise network via virtual LAN - require a Fixed IP Address. + may also require this type of address. Enterprise applications that + connect to an enterprise network via virtual LAN require a Fixed IP + Address. - Applications with short-lived transient IP sessions can use Sustained - IP Addresses. For example: Web browsers. + Applications with short-lived transient IP sessions can use Session- + lasting IP Addresses. For example: Web browsers. Applications with very short IP sessions, such as DNS client and - instant messengers, can utilize Nomadic IP Addresses. Even though - they could very well use a Fixed of Sustained IP Addresses, the - transmission latency would be minimized when a Nomadic IP Address is - used. + instant messengers, can utilize Non-persistent IP Addresses. Even + though they could very well use a Fixed of Session-lasting IP + Addresses, the transmission latency would be minimized when a Non- + persistent IP Address is used. 3.2. Granularity of Selection The IP address type selection is made on a per-socket granularity. Different parts of the same application may have different needs. For example, control-plane of an application may require a Fixed IP Address in order to stay reachable, whereas data-plane of the same - application may be satisfied with a Sustained IP Address. + application may be satisfied with a Session-lasting IP Address. 3.3. On Demand Nature At any point in time, a mobile host may have a combination of IP - addresses configured. Zero or more Nomadic, zero or more Sustained, - and zero or more Fixed IP addresses may be configured on the IP stack - of the host. The combination may be as a result of the host policy, - application demand, or a mix of the two. + addresses configured. Zero or more Non-persistent, zero or more + Session-lasting, and zero or more Fixed IP addresses may be + configured on the IP stack of the host. The combination may be as a + result of the host policy, application demand, or a mix of the two. - When the application requires a specific type of IP address and such - an IP address is not already configured on the host, then the IP - stack shall attempt to configure one. For example, a host may not - always have a Fixed IP address available as such an address is rarely - used. In case an application requests one, then the IP stack shall - make an attempt to configure one using Mobile IP. If Mobile IP - protocol is not available on the stack, or if its operation fails, - then the IP stack shall fail the associated socket request. In case - of successful Mobile IP operation, a Fixed IP Address gets configured - on the mobile host. If another socket requests a Fixed IP address at - a later time, then the same IP address may be served to that socket - as well. When the last socket using the requested IP address is - closed, the IP address may be released or kept for future - applications that may be launched and require a Fixed IP address. + When an application requires a specific type of IP address and such + address is not already configured on the host, the IP stack shall + attempt to configure one. For example, a host may not always have a + Session-lasting IP address available. In case an application + requests one, the IP stack shall make an attempt to configure one by + issuing a request to the network. If the operation fails, the IP + stack shall fail the associated socket request. If successful, a + Session-lasting IP Address gets configured on the mobile host. If + another socket requests a Session-lasting IP address at a later time, + the same IP address may be served to that socket as well. When the + last socket using the requested IP address is closed, the IP address + may be released or kept for future applications that may be launched + and require a Session-lasting IP address. + + In some cases it might be preferable for the mobile host to request a + new Session-lasting IP address for a new opening of an IP session + (even though one was already assigned to the mobile host by the + network and might be in use in a different, already active IP + session). It is out of the scope of this specification to define + criteria for selecting to use available addresses or choose to + request new ones. It supports both alternatives (and any + combination). + + It is outside of the scope of this specification to define how the + host requests a specific type of address (Fixed, Session-lasting or + Non-persistent) and how the network indicates the type of address in + its advertisement of addresses (or in its reply to an address + request). The following are matters of policy, which may be dictated by the host itself, the network operator, or the system architecture standard: - The initial set of IP addresses configured on the host at the boot time. - Permission to grant various types of IP addresses to a requesting application. @@ -255,30 +268,31 @@ 3.4. Conveying the Selection The selection of the address type is conveyed from the applications to the IP stack in a way to influence the source address selection algorithm [RFC6724]. The current source address selection algorithm operates on the available set of IP addresses when selecting an address. According to the proposed solution, if the requested type IP address is not - available at the time of the request, then the IP stack shall make an + available at the time of the request, the IP stack shall make an attempt to configure one such IP address. The selected IP address shall be compliant with the requested IP address type, whether it is selected among available addresses or dynamically configured. In the absence of a matching type (because it is not available and not configurable on demand), the source address selection algorithm shall return an empty set. A Socket API-based interface for enabling applications to influence the source address selection algorithm is described in [RFC5014]. + That specification defines IPV6_ADDR_PREFERENCES option at the IPPROTO_IPV6 level. That option can be used with setsockopt() and getsockopt() calls to set and get address selection preferences. Furthermore, that RFC also specifies two flags that relate to IP mobility management: IPV6_PREFER_SRC_HOME and IPV6_PREFER_SRC_COA. These flags are used for influencing the source address selection to prefer either a Home Address or a Care-of Address. Unfortunately, these flags do not satisfy the aforementioned needs @@ -296,24 +310,25 @@ - The Home vs. Care-of Address distinction is not sufficient to capture the three different types of IP addresses described in Section 2.1. The following new flags are defined in this document and they shall be used with Socket API in compliance with the [RFC5014]: IPV6_REQUIRE_FIXED_IP /* Require a Fixed IP address as source */ - IPV6_REQUIRE_SUSTAINED_IP /* Require a Sustained IP address as source - */ + IPV6_REQUIRE_Session-lasting_IP /* Require a Session-lasting IP + address as source */ - IPV6_REQUIRE_NOMADIC_IP /* Require a Nomadic IP address as source */ + IPV6_REQUIRE_Non-persistent_IP /* Require a Non-persistent IP address + as source */ Only one of these flags may be set on the same socket. If an application attempts to set more than one flag, the most recent setting will be the one in effect. When any of these new flags is used, then the IPV6_PREFER_SRC_HOME and IPV6_PREFER_SRC_COA flags, if used, shall be ignored. These new flags are used with setsockopt()/getsockopt(), getaddrinfo(), and inet6_is_srcaddr() functions [RFC5014]. Similar