wdiff rfc8653.original rfc8653.txt

DMM Working Group

Internet Engineering Task Force (IETF) A. Yegin
Internet-Draft
Request for Comments: 8653 Actility
Intended status:
Category: Informational D. Moses
Expires: January 31, 2020
ISSN: 2070-1721 Intel
S. Jeon
Sungkyunkwan University
July 30,
October 2019

On Demand

On-Demand Mobility Management
draft-ietf-dmm-ondemand-mobility-18

Abstract

Applications differ with respect to whether they need 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, as described in [RFC7333]. RFC 7333. This
document defines a new concep concept of enabling applications to influence
the network's mobility services (session continuity and/or IP address
reachability) on a per-Socket per-socket basis, and suggests extensions to the
networking stack's API to accomodate accommodate this concept.

Status of This Memo

This Internet-Draft document is submitted in full conformance with the
provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents not an Internet Standards Track specification; it is
published for informational purposes.

This document is a product of the Internet Engineering Task Force
(IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list It represents the consensus of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents valid
approved by the IESG are candidates for a maximum any level of Internet
Standard; see Section 2 of six months RFC 7841.

Information about the current status of this document, any errata,
and how to provide feedback on it may be updated, replaced, or obsoleted by other documents obtained 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 31, 2020.
https://www.rfc-editor.org/info/rfc8653.

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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4
3. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. High-level High-Level Description . . . . . . . . . . . . . . . . . 4
3.2. Types of IP Addresses . . . . . . . . . . . . . . . . . . 5
3.3. Granularity of Selection . . . . . . . . . . . . . . . . 6
3.4. On Demand On-Demand Nature . . . . . . . . . . . . . . . . . . . . 6
4. Backwards Compatibility Considerations . . . . . . . . . . . 7
4.1. Applications . . . . . . . . . . . . . . . . . . . . . . 8
4.2. IP Stack in the Mobile Host . . . . . . . . . . . . . . . 8
4.3. Network Infrastructure . . . . . . . . . . . . . . . . . 8
4.4. Merging this work with RFC5014 . . . . . . . . . . . . . 8 RFC 5014
5. Security Considerations . . . . . . . . . . . . . . . . . . . 9
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
9.1.
7.1. Normative References . . . . . . . . . . . . . . . . . . 10
9.2.
7.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Conveying the Desired Address Type . . . . . . . . . 11
Acknowledgements
Contributors
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12

1. Introduction

In the context of Mobile IP [RFC5563][RFC6275][RFC5213][RFC5944], [RFC5563] [RFC6275] [RFC5213] [RFC5944],
the following two attributes are defined for IP service provided to
mobile hosts:

Session Continuity
The ability to maintain an ongoing transport interaction by
keeping the same local end-point endpoint IP address throughout the life-time lifetime
of the IP socket despite the mobile host changing its point of
attachment within the IP network topology. The IP address of the
host may change after closing the IP socket and before opening a
new one, but that does not jeopardize the ability of applications
using these IP sockets to work flawlessly. Session continuity is
essential for mobile hosts to maintain ongoing flows without any
interruption.

IP Address Reachability
The ability to maintain the same IP address for an extended period
of time. The IP address stays the same across independent
sessions, and even in the absence of any session. The IP address may
be published in a long-term registry (e.g., DNS), DNS) and is made
available for serving incoming (e.g., TCP) connections. IP
address reachability is essential for mobile hosts to use
specific/published IP addresses.

Mobile IP is designed to provide both session continuity and IP
address reachability to mobile hosts. Architectures utilizing using these
protocols (e.g., 3GPP, 3GPP2, WIMAX) WiMAX) ensure that any mobile host
attached to the a compliant networks network can enjoy these benefits. Any
application running on these mobile hosts is subjected to the same
treatment with respect to session continuity and IP address
reachability.

Achieving session continuity and IP address reachability with Mobile
IP incurs some cost. Mobile IP protocol forces the mobile host's IP traffic
to traverse a centrally-located centrally located router (Home Agent, HA), which incurs
additional transmission latency and use of additional network
resources, adds to the network CAPEX network's operating and OPEX, capital expenditures,
and decreases the reliability of the network due to the introduction
of a single point of failure [RFC7333]. Therefore, session
continuity and IP address reachability SHOULD be provided only when
necessary.

In reality reality, not every application may need these benefits. IP
address reachability is required for applications running as servers
(e.g., a web server running on the mobile host). But, host), but a typical client
application (e.g., web browser) does not necessarily require IP
address reachability. Similarly, session continuity is not required
for all types of applications either. Applications performing brief
communication (e.g., text messaging) can survive without having
session continuity support.

Furthermore, when an application needs session continuity, it may be
able to satisfy that need by using a solution above the IP layer,
such as MPTCP Multipath TCP [RFC6824], SIP mobility [RFC3261], or an application-
layer
application-layer mobility solution. These higher-layer solutions
are not subject to the same issues that arise with the use of Mobile
IP since they can utilize use the most direct data path between the end-points.
endpoints. But, if Mobile IP is being applied to the mobile host,
the higher-
layer higher-layer protocols are rendered useless because their
operation is inhibited by Mobile IP. Since Mobile IP ensures that
the IP address of the mobile host remains fixed (despite the location
and movement of the mobile host), the higher-layer protocols never
detect the IP-
layer IP-layer change and never engage in mobility management.

This document proposes a solution for applications running on mobile
hosts to indicate when establishing the network connection ('on
demand') whether they need session continuity or IP address
reachability. The network protocol stack on the mobile host, in
conjunction with the network infrastructure, provides the required
type of service. It is for the benefit of both the users and the
network operators not to engage an extra level of service unless it
is absolutely necessary. It is expected that applications and
networks compliant with this specification will utilize this solution
to use network resources more efficiently.

2. Notational Conventions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 , [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.

3. Solution

3.1. High-level High-Level Description

Enabling applications to indicate their mobility service requirements
e.g.
(e.g., session continuity and/or IP address reachability, reachability) comprises
the following steps:

1. The application indicates to the network stack (local to the
mobile host) the desired mobility service.

2. The network stack assigns a source IP address based on an IP
prefix with the desired services that was previously provided by
the network. If such an IP prefix is not available, the network
stack performs the additional steps below.

3. The network stack sends a request to the network for a new source
IP prefix that is associated with the desired mobility service.

4. The network responds with the suitable allocated source IP prefix
(or responds with a failure indication).

5. If the suitable source IP prefix was allocates, allocated, the network stack
constructs a source IP address and provides it to the
application.

This document specifies the new address types associated with
mobility services and details the interaction between the
applications and the network stack steps. It uses the Socket socket
interface as an example for an API between applications and the
network stack. Other steps are outside the scope of this document.

3.2. Types of IP Addresses

Four types of IP addresses are defined with respect to mobility
management.

-
management:

Fixed IP Address address
A Fixed IP address is an address with a guarantee guaranteed to be valid for a very
long time, regardless of whether it is being used in any packet
to/from the mobile host, or whether or not the mobile host is
connected to the network, or whether it moves from one point-of- point of
attachment to another (with a different IP prefix) while it is
connected.

Fixed IP addresses are required by applications that need both
session continuity and IP address reachability.

- Session-lasting

Session-Lasting IP Address address
A session-lasting Session-Lasting IP address is an address with a guarantee guaranteed to be valid throughout
for the life-time lifetime of the socket(s) for which it was requested. It
is guaranteed to be valid even after the mobile host
had has moved
from one point-of-attachment point of attachment to another (with a different IP
prefix).

Session-lasting

Session-Lasting IP addresses are required by applications that
need session continuity but do not need IP address reachability.

- Non-persistent

Nonpersistent IP Address address
This type of IP address has no guarantee is not guaranteed to exist after a mobile
host moves from one point-of-attachment point of attachment to another, and another; therefore, no
session continuity nor IP address reachability are provided. The
IP address is created from an IP prefix that is obtained from the
serving IP gateway and is not maintained across gateway changes.
In other words, the IP prefix may be released and replaced by a
new one when the IP gateway changes due to the movement of the
mobile host forcing the creation of a new source IP address with
the updated allocated IP prefix.

- Graceful Replacement

Graceful-Replacement IP Address address
In some cases, the network cannot guarantee the validity of the
provided IP prefix throughout the duration of the opened socket,
but can provide a limited graceful period of time in which both
the original IP prefix and a new one are valid. This enables the
application some flexibility in the transition from the existing
source IP address to the new one.

This gracefulness is still better than the non-persistence nonpersistence type of
address for applications that can handle a change in their source
IP address but require that extra flexibility.

Applications running as servers at a published IP address require a
Fixed IP Address. address. Long-standing applications (e.g., an SSH session)
may also require this type of address. Enterprise applications that
connect to an enterprise network via virtual LAN require a Fixed IP
Address.
address.

Applications with short-lived transient sessions (e.g., web browsers)
can use Session-
lasting Session-Lasting IP Addresses. For example: Web browsers. addresses.

Applications with very short sessions, such as DNS clients and
instant messengers, can utilize Non-persistent use Nonpersistent IP Addresses. addresses. Even though
they could very well use Fixed or Session-lasting Session-Lasting IP
Addresses, addresses, the
transmission latency would be minimized when a Non-
persistent Nonpersistent IP Addresses are
address is used.

Applications that can tolerate a short interruption in connectivity
can use the Graceful-replacement Graceful-Replacement IP addresses. For addresses, for example, a
streaming client that has buffering capabilities.

3.3. Granularity of Selection

IP address type selection is made on a per-socket granularity.
Different parts of the same application may have different needs.
For example, the control-plane control plane of an application may require a Fixed
IP Address address in order to stay reachable, whereas the data-plane data plane of the
same application may be satisfied with a Session-lasting Session-Lasting IP Address. address.

3.4. On Demand On-Demand Nature

At any point in time, a mobile host may have a combination of IP
addresses configured. Zero or more Fixed, zero or more Session-
lasting,
Lasting, zero or more Non-persistent Nonpersistent, and zero or more Graceful-
Replacement IP addresses may be configured by 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 an application requires a specific type of IP address address, and such
an 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
Session-Lasting IP address available. When 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 and return an error. If
successful, a Session-lasting Session-Lasting IP Address gets address is configured on the mobile
host. If another socket requests a Session-lasting 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 same configured IP address is closed,
the IP address may be released released, or it may be kept for future applications
requiring a Session-Lasting IP address that may be launched and require a Session-lasting IP
address. in the
future.

In some cases cases, it might be preferable for the mobile host to request
a new Session-lasting Session-Lasting IP address for a new opening of an IP socket
(even though one was already assigned to the mobile host by the
network and might be in use in a different, already active IP
sockets).
socket). It is outside the scope of this specification to define
criteria for choosing to use available addresses or choosing to
request new ones. It supports both alternatives (and any
combination).

It is outside the scope of this specification to define how the host
requests a specific type of prefix and how the network indicates the
type of prefix in its advertisement or in its reply to a 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 boot
time.

-
time

* Permission to grant various types of IP addresses to a requesting
application.

-
application

* Determination of a default address type when an application does
not make any explicit indication, explicitly indicate whether it already supports the required API or it is just
a legacy application. application

4. Backwards Compatibility Considerations

Backwards compatibility support is REQUIRED by the following 3 three
types of entities:

* The Applications applications on the mobile host

* The IP stack in the mobile host

* The network infrastructure

4.1. Applications

Legacy applications that do not support the On-Demand functionality
will use the legacy API and will not be able to take advantage of the
On-Demand Mobility feature.

Applications using the new On-Demand functionality should be aware
that they may be executed in legacy environments that do not support
it. Such environments may include a legacy IP stack on the mobile
host, legacy network infrastructure, or both. In either case, the
API will return an error code code, and the invoking applications application may just
give up and use legacy calls.

4.2. IP Stack in the Mobile Host

New IP stacks (that implement On Demand On-Demand functionality) MUST continue
to support all legacy operations. If an application does not use On-
Demand functionality, the IP stack MUST respond in a legacy manner.

If the network infrastructure supports On-Demand functionality, the
IP stack SHOULD follow the application request: If the application
requests a specific address type, the stack SHOULD forward this
request to the network. If the application does not request an
address type, the IP stack MUST NOT request an address type and leave
it to type.
Instead, the network's default behavior to network will choose the type of the allocated IP prefix.
How the network selects the type of allocated IP prefix is outside
the scope of this document. If an IP prefix was already allocated to
the host, the IP stack uses it and may not request a new one from the
network.

4.3. Network Infrastructure

The network infrastructure may or may not support the On-Demand
functionality. How the IP stack on the host and the network
infrastructure behave in case of a compatibility issue is outside the
scope of this API specification.

4.4. Merging this work with RFC5014 RFC 5014

[RFC5014] defines new flags that may be used with setsockopt() to
influence source IP address selection for a socket. The list of
flags include: include the following: source home address, care-of address,
temporary address, public address CGA (Cryptographically Created Address)
Address), and non-CGA. When applications require session continuity
service, they SHOULD NOT set the flags specified in [RFC5014].

However, if an application erroneously performs a combination of (1)
Use
using setsockopt() to set a specific option (using one of the flags
specified in [RFC5014]) and (2) Selects selecting a source IP address type,
the IP stack will fulfill the request specified by (2) and ignore the
flags set by (1).

5. Security Considerations

The different service types (session continuity types and address
reachability) associated with the allocated IP address types, types may be
associated with different costs. The costs: the cost to the operator for
enabling a type of service, and the cost to applications using a
selected service. A malicious application may use these to
indirectly generate extra billing of a mobile subscriber, and/or
impose costly services on the mobile operator. When costly expensive
services are limited, malicious applications may exhaust them,
preventing other applications on the same mobile host from being able
to use them.

Mobile hosts that enables enable such service options, options should provide
capabilities for ensuring that only authorized applications can use
the costly expensive (or limited) service types.

The ability to select service types requires the exchange of the
association of source IP prefixes and their corresponding service
types, between the mobile host and mobile network. Exposing these
associations may provide information to passive attackers even if the
traffic that is used with these addressed addresses is encrypted.

To avoid profiling an application according to the type of IP
addresses,
address, it is expected that prefixes provided by the mobile operator
are associated to with various type types of addresses over time. As a
result, the type of address could not cannot be associated to with the prefix,
making application profiling based on the type of address harder. more
difficult.

The application or the OS should ensure that IP addresses regularly
change to limit IP tracking by a passive observer. The application
should regularly set the On Demand On-Demand flag. The application should be
able to ensure that session lasting Session-Lasting IP addresses are regularly
changed by setting a lifetime lifetime, for example example, handled by the
application. In addition, the application should consider the use of graceful
replacement
Graceful-Replacement IP addresses.

Similarly, the OS may also associated associate IP addresses with a lifetime.
Upon receiving a request for a given type of IP address, after some
time, the OS should request a new address to the network even if it
already has one IP address available with the requested type. This
includes any type of IP address. IP addresses of type graceful
replacement Graceful-
Replacement or non persistent nonpersistent should be regularly renewed by the OS.

The lifetime of an IP address may be expressed in number of seconds
or in number of bytes sent through this IP address.

6. IANA Considerations

This document has no IANA considerations. actions.

7. Contributors

This document was merged with [I-D.sijeon-dmm-use-cases-api-source].
We would like to acknowledge the contribution of the following people
to that document as well:

Sergio Figueiredo
Altran Research, France
Email: sergio.figueiredo@altran.com

Younghan Kim
Soongsil University, Korea
Email: younghak@ssu.ac.kr

John Kaippallimalil
Huawei, USA
Email: john.kaippallimalil@huawei.com

8. Acknowledgements

We would like to thank Wu-chi Feng, Alexandru Petrescu, Jouni
Korhonen, Sri Gundavelli, Dave Dolson Lorenzo Colitti and Daniel
Migault for their valuable comments and suggestions on this work.

9. References

9.1.

7.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.

[RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6
Socket API for Source Address Selection", RFC 5014,
DOI 10.17487/RFC5014, September 2007,
<https://www.rfc-editor.org/info/rfc5014>.

[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.

9.2.

7.2. Informative References

[I-D.sijeon-dmm-use-cases-api-source]

[API-EXT] Jeon, S., Figueiredo, S., Kim, Y., and J. Kaippallimalil,
"Use Cases and API Extension for Source IP Address
Selection", draft-sijeon-dmm-use-cases-api-source-07 (work Work in progress), Progress, Internet-Draft, draft-
sijeon-dmm-use-cases-api-source-07, 10 September 2017. 2017,
<https://tools.ietf.org/html/draft-sijeon-dmm-use-cases-
api-source-07>.

[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261,
DOI 10.17487/RFC3261, June 2002,
<https://www.rfc-editor.org/info/rfc3261>.

[RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
RFC 5213, DOI 10.17487/RFC5213, August 2008,
<https://www.rfc-editor.org/info/rfc5213>.

[RFC5563] Leung, K., Dommety, G., Yegani, P., and K. Chowdhury,
"WiMAX Forum / 3GPP2 Proxy Mobile IPv4", RFC 5563,
DOI 10.17487/RFC5563, February 2010,
<https://www.rfc-editor.org/info/rfc5563>.

[RFC5944] Perkins, C., Ed., "IP Mobility Support for IPv4, Revised",
RFC 5944, DOI 10.17487/RFC5944, November 2010,
<https://www.rfc-editor.org/info/rfc5944>.

[RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July
2011, <https://www.rfc-editor.org/info/rfc6275>.

[RFC6824] Ford, A., Raiciu, C., Handley, M., and O. Bonaventure,
"TCP Extensions for Multipath Operation with Multiple
Addresses", RFC 6824, DOI 10.17487/RFC6824, January 2013,
<https://www.rfc-editor.org/info/rfc6824>.

[RFC7333] Chan, H., Ed., Liu, D., Seite, P., Yokota, H., and J.
Korhonen, "Requirements for Distributed Mobility
Management", RFC 7333, DOI 10.17487/RFC7333, August 2014,
<https://www.rfc-editor.org/info/rfc7333>.

Appendix A. Conveying the Desired Address Type

Following

The following are some suggestions of possible extensions to the Socket
socket API for enabling applications to convey their session
continuity and address reachability requirements.

[RFC5014] introduced the ability of applications to influence the
source address selection with the IPV6_ADDR_PREFERENCE option at the
IPPROTO_IPV6 level. This option is used with setsockopt() and
getsockopt() calls to set/get address selection preferences.

One alternative is to extend the defintion definition of the
IPV6_ADDR_REFERENCE
opion option with flags that express the invoker's
desire. An "OnDeman" "OnDemand" field could contains contain one of the following
values: FIXED_IP_ADDRESS, SESSION_LASTING_IP_ADDRESS, NON_PERSISTENT_IP_ADDRESS
NON_PERSISTENT_IP_ADDRESS, or GRACEFUL_REPLACEMENT_IP_ADDRESS.

Another alternative is to define a new Socket socket function used by the
invoker to convey its desire. This enables the implementation of two
behaviors of Socket socket functions: The the existing "setsockotp()" setsockopt() is a
function that returns after executing, and the new "setsc()" setsc() (Set
Service Contionuity) Continuity) is a function that may initaite initiate a request for the
desired service, and wait until the network responds with the
allocated resources, before returning to the invoker.

After obtaining an IP address with the desired behavior behavior, the
application can call the bind() Socket socket function to associate that
received IP address with the socket.

Acknowledgements

We would like to thank Wu-chi Feng, Alexandru Petrescu, Jouni
Korhonen, Sri Gundavelli, Dave Dolson, Lorenzo Colitti, and Daniel
Migault for their valuable comments and suggestions on this work.

Contributors

This document was merged with "Use Cases and API Extension for Source
IP Address Selection" [API-EXT]. We would like to acknowledge the
contribution of the following people to that document as well:

Sergio Figueiredo
Altran Research
France
Email: sergio.figueiredo@altran.com

Younghan Kim
Soongsil University
Republic of Korea
Email: younghak@ssu.ac.kr

John Kaippallimalil
Huawei
United States of America
Email: john.kaippallimalil@huawei.com

Authors' Addresses

Alper Yegin
Actility
Istanbul
Istanbul/
Turkey

Email: alper.yegin@actility.com

Danny Moses
Intel Corporation
Petah Tikva
Israel

Email: danny.moses@intel.com

Seil Jeon
Republic of Korea
Suwon
Sungkyunkwan University
Suwon
South Korea

Email: seiljeon@skku.edu seiljeon.ietf@gmail.com