Cloud Based Mobile Core Network Problem Statement
draft-liu-dmm-deployment-scenario-01
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| Authors | Dapeng Liu , Anthony Chan , DENG Hui | ||
| Last updated | 2014-03-03 | ||
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draft-liu-dmm-deployment-scenario-01
Network Working Group D. Liu
Internet-Draft China Mobile
Intended status: Informational H. Chan
Expires: September 4, 2014 Huawei Technologies
H. Deng
China Mobile
March 3, 2014
Cloud Based Mobile Core Network Problem Statement
draft-liu-dmm-deployment-scenario-01
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 understnad the DMM deployment scenario and
consideration from the operator's perspective.
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This Internet-Draft will expire on September 4, 2014.
Copyright Notice
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions used in this document . . . . . . . . . . . . . . . 3
3. Deployment Scenario and Model of DMM . . . . . . . . . . . . . 3
4. Network Function Virtualization . . . . . . . . . . . . . . . . 3
4.1. Network Function Virtualization Scenario . . . . . . . . . 4
4.2. Control and data plane separation . . . . . . . . . . . . . 4
4.3. Mobility management functions . . . . . . . . . . . . . . . 5
5. SIPTO deployment scenario . . . . . . . . . . . . . . . . . . . 6
6. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 7
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7
11. Normative References . . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7
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1. Introduction
Distributed mobility management aims at solving the centralized
mobility anchor problems of the tranditional 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].
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 routing'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.
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4.1. Network Function Virtualization Scenario
The network function virtualization scenario is shown in Figure 1.
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 plane. 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.
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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.
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 functions
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 routing 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 management (LM) and Routing management
(RM). The former is a control plane function. The latter can be
separated into data plane routing management (RM-DP) and control
plane routing management (RM-CP).
The data plane function is RM-DP which may also be called a Data
Plane Anchor (DPA). The control plane functions include RM-CP and LM
and may be called a Control Plane Anchor (CPA). Then the control
plane functions in the cloud-based mobile core includes LM and RM-CP
or CPA. They are of cause other functions in the control plane such
as policy function. The distributed data plane may have multiple
instances of RM-DP / DPA in the network.
core network controller
+---------------+
|LM, RM-CP / CPA|
+---------------+
+-------------+ +-------------+ +-------------+
| RM-DP / DPA | | RM-DP / DPA | | RM-DP / DPA |
+-------------+ +-------------+ +-------------+
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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.
Access network controller Core network controller
+---------------+ +---------------+
|LM, RM-CP / CPA| |LM, RM-CP / CPA|
+---------------+ +---------------+
+-------------+ +-------------+ +-------------+ +-------------+
| RM-DP / DPA | | RM-DP / DPA | | RM-DP / DPA | | RM-DP / DPA |
+-------------+ +-------------+ +-------------+ +-------------+
Figure 2: Mobility management functions with data plane - control
plane separation with separate control in core and in access.
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 requirment of
application. 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.
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8. IANA Considerations
N/A.
9. Contributors
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.
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
Hui Deng
China Mobile
No.32 Xuanwumen West Street
Beijing 100053
China
Email: denghui@chinamobile.com
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