Network Working Group D. Liu
Internet-Draft China Mobile
Intended status: Informational H. Chan
Expires: January 5, 2015 Huawei Technologies
H. Deng
China Mobile
July 4, 2014
Distributed mobility management deployment scenario and architecture
draft-liu-dmm-deployment-scenario-02
Abstract
This document discusses the deployment scenario of distributed
mobility management. The purpose of this document is to trigger the
discussion in the group to understand the DMM deployment scenario and
consideration from the operator's perspective.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions used in this document . . . . . . . . . . . . . . . 3
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Deployment Scenario and Model of DMM . . . . . . . . . . . . . 4
4. Network Function Virtualization . . . . . . . . . . . . . . . . 4
4.1. Network Function Virtualization Scenario . . . . . . . . . 4
4.2. Control and data plane separation . . . . . . . . . . . . . 5
4.3. Mobility management architecture . . . . . . . . . . . . . 6
5. SIPTO deployment scenario . . . . . . . . . . . . . . . . . . . 7
6. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 8
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8
11. Normative References . . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8
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1. Introduction
Distributed mobility management aims at solving the centralized
mobility anchor problems of the traditional mobility management
protocol. The benefit of DMM solution is that the data plane traffic
does not need to traverse the centralized anchoring point. This
document discusses the potential deployment scenario of DMM. The
purpose of this document is to help the group to reach consensus
regarding the deployment model of DMM and then develop the DMM
solution based on the deployment model.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL","SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2.1. Terminology
All the general mobility-related terms and their acronyms used in
this document are to be interpreted as defined in the Mobile IPv6
base specification [RFC6275], in the Proxy mobile IPv6 specification
[RFC5213], and in Mobility Related Terminology [RFC3753]. These
terms include the following: mobile node (MN), correspondent node
(CN), and home agent (HA) as per [RFC6275]; local mobility anchor
(LMA) and mobile access gateway (MAG) as per [RFC5213], and context
as per [RFC3753].
In addition, this draft introduces the following terms.
Location information (LI) function
is the logical function that manages and keeps track of the
internetwork location information of a mobile node which may
change its IP address as it moves. The information may associate
with each session identifier, the IP routing address of the MN, or
of a node that can forward packets destined to the MN.
Forwarding management (FM)
is the logical function that intercepts packets to/from the IP
address/prefix delegated to a mobile node and forwards them, based
on internetwork location information, either directly towards
their destination or to some other network element that knows how
to forward the packets to their ultimate destination. With data
plane and control plane separation, the forwarding management may
be separated into a data-plane forwarding management (FM-DP)
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function and a control-plane forwarding management (FM-CP)
function.
3. Deployment Scenario and Model of DMM
As discussed in the DMM requirement document, the centralized
mobility management has several drawbacks. The main problem of the
centralized mobility management protocols is that all the traffic
need to anchor to a centralized anchor point. This approach does not
cause any problem in current mobile network deployment but in the
scenario that will be discussed later in this document, centralized
mobility management protocols will have many drawbacks and it is
believed that DMM is more suitable in that scenario.
The main deployment scenario discussed in this document is divided
into two types. The first one is the network function virtualization
scenario. In this scenario, the mobile core network's control plane
function is centralized in the mobile cloud. Apparently, deploying
the data plane function also in the same centralized mobile cloud is
not optimized from the traffic forwarding's perspective. Another
deployment scenario is the SIPTO/LIPA scenario which is discussed in
3GPP. In this scenario, DMM can provide optimized traffic offloading
solution.
4. Network Function Virtualization
This section discusses network function virtualization scenario, the
associated control - data plane separation and the possible mobility
management functions to support this scenario.
4.1. Network Function Virtualization Scenario
The network function virtualization scenario is shown in Figure 1.
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Mobile Cloud
...........
(' ')
( )))
((( +-----------+ )))
(( |Mobile Core| )))
((( +-----------+ )))
('..............')
|
| IP Transit Network
(.........)
( )) MN-Internet communication
( ^ ))
^ > > >( ^ ))> > > > > > > > >
^ (( ^ ) v
^ (.........^.) v
^ +-------| | ^| v
^ | | ^+--------------+ v
^ | | < < | v MN-MN communication
^ | | ^ | v
+--------------+ +--------------+ +--------------+
|Access Network| |Access Network| |Access Network|
+--------------+ +--------------+ +--------------+
^ ^ v
^ ^ v
+---------+ +---------+ +---------+
| MN | | MN | | MN |
+---------+ +---------+ +---------+
Figure 1: Network function virtualization deployment architecture
In this architecture, the mobile core network is located in the cloud
/data center, which can be the operator's private cloud. The access
network is connected through an IP transit network. The mobile core
network can run in a virtualized platform in the cloud/datacenter.
4.2. Control and data plane separation
The cloud based mobile core network architecture implies separation
of the control and data planes. The control plane is located in the
cloud and the data plane should be distributed. Otherwise, all the
data traffic will go through the cloud which is obviously not
optimized for the mobile node to mobile node communication.
For the mobile node to Internet communication, the Internet access
point is normally located in the metro IP transit network. In this
case, the mobile node to Internet traffic should also go through the
Internet access point instead of the mobile core in the cloud.
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However, in some deployment scenario, the operator may choose to put
the mobile core cloud in the convergence layer of IP metro network.
In this case, the Internet access point may co-located with the
mobile core cloud. In this case, the mobile node to Internet traffic
may go through the mobile core cloud.
4.3. Mobility management architecture
Since the control plane and data plane are separated and the data
plane is distributed, traditional mobility management cannot meet
this requirement.
Distributed mobility management or SDN based mobility management may
be used in this architecture to meet the traffic forwarding
requirement (e.g. MN to MN and MN to Internet traffic should not go
through from the mobile core cloud.).
The traditional mobility management functions is not separating the
data plane from the control plane. Basic mobility management
functions include location information (LI) function and Forwarding
management (FM). The former is a control plane function. The latter
can be separated into data plane forwarding management (FM-DP) and
control plane forwarding management (FM-CP).
The data plane function is FM-DP, while the control plane functions
include FM-CP and LI. Then the control plane functions in the cloud-
based mobile core includes LI and FM-CP. They are of cause other
functions in the control plane such as policy function. The
distributed data plane may have multiple instances of FM-DP in the
network.
core network controller
+---------+
|LI, FM-CP|
+---------+
+-------+ +-------+ +-------+
| FM-DP | | FM-DP | | FM-DP |
+-------+ +-------+ +-------+
Figure 2: Mobility management functions with data plane - control
plane separation under one controller
When the control of the access network is separate from that of the
core, there will be separate controllers as shown in Figure 3.
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Access network controller Core network controller
+---------+ +---------+
|LI, FM-CP| |LI, FM-CP|
+---------+ +---------+
+-------+ +-------+ +-------+ +-------+
| FM-DP | | FM-DP | | FM-DP | | FM-DP |
+-------+ +-------+ +-------+ +-------+
Figure 2: Mobility management functions with data plane - control
plane separation with separate control in core and in access
networks.
5. SIPTO deployment scenario
Another deployment scenario is the SIPTO scenario which is discussed
in 3GPP. DMM is believed to be able to provide dynamic anchoring.
It allows the mobile node to have several anchoring points and to
change the anchoring point according to the application requirement.
In SIPTO scenario, the gateway function is located very near to the
access network and to the user. If using current centralized
mobility management, the traffic will need to tunnel back to the
previous anchor point even when the mobile node has changed the point
of attachment to a new one.
6. Conclusion
This document discusses the deployment scenario of DMM. Two types of
deployment scenario is discussed in this document. Further types of
deployment scenario can be added to this document according to the
progress of the group's discussion.
7. Security Considerations
N/A.
8. IANA Considerations
N/A.
9. Contributors
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10. Acknowledgements
11. Normative References
[IEEE-802.11.2012]
"", March 2012.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3753] Manner, J. and M. Kojo, "Mobility Related Terminology",
RFC 3753, June 2004.
[RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.
[RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support
in IPv6", RFC 6275, July 2011.
Authors' Addresses
Dapeng Liu
China Mobile
No.32 Xuanwumen West Street
Beijing 100053
China
Email: liudapeng@chinamobile.com
H Anthony Chan
Huawei Technologies
5340 Legacy Dr. Building 3
Plano, TX 75024
USA
Email: h.a.chan@ieee.org
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Hui Deng
China Mobile
No.32 Xuanwumen West Street
Beijing 100053
China
Email: denghui@chinamobile.com
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