Network Working Group V.Liu
Internet Draft ChinaMobile
Intended status: Standards Track D.Liu
Expires: Mar 18, 2016 Alibaba
H. Chan
Huawei Technologies
H. Deng
China Mobile
X.Wei
Huawei Technologies
October 19, 2015
Distributed mobility management deployment scenario and architecture
draft-liu-dmm-deployment-scenario-05
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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.
Table of Contents
Table of Contents ................................................ 2
1. Introduction .................................................. 2
2. Conventions used in this document.............................. 3
2.1. Terminology .............................................. 3
3. Deployment Scenario and Model of DMM........................... 3
4. Network Function Virtualization Scenario....................... 4
4.1. Network function virtualization deployment architecture... 4
4.2. Control and data plane separation......................... 6
4.3. Mobility management architecture.......................... 6
4.4 NFV based deployment architecture......................... 7
5. SIPTO deployment scenario...................................... 8
6. WLAN deployment scenario....................................... 9
7. Conclusion ................................................... 10
8. Security Considerations....................................... 10
9. IANA Considerations .......................................... 10
10. Normative References......................................... 11
11. Informative References....................................... 11
12. Acknowledgments ............................................. 11
Authors' Addresses .............................................. 12
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
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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 internet
work 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) 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
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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 three scenarios. 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. For the control plane The MME and PGW-F
are implemented by NFV. For the dataplane the PGW-F/SGW-F can
weither be implemented by NFV or lagacy devices. The second
deployment scenario is the SIPTO/LIPA scenario which is discussed in
3GPP. In this scenario, DMM can provide optimized traffic offloading
solution. The Third deploy scenario is the WLAN scenario. In this
scenario, the AC is implemented in the cloud and the authentication
status can maintained as the terminal move from one AP to another.
4. Network Function Virtualization Scenario
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 deployment architecture
The network function virtualization scenario is shown in Figure 1.
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Mobile Cloud
...........
(' ')
( )))
((( +-----------+ )))
(( |Mobile Core| )))
(( |MME+P/SGW-C| )))
((( +-----------+ )))
('..............')
|
| IP Transit Network
(.........)
( )) MN-Internet communication
( ^ ))
^ > > >( ^ ))> > > > > > > > >
^ (( ^ ) v
^ (.........^.) v
^ +-------| | ^| v
^ | | ^+--------------+ v
^ | | < < | v MN-MN communication
^ | | ^ | v
+--------------+ +--------------+ +--------------+
|Access Network| |Access Network| |Access Network|
| PGW-F/SGW-F | | PGW-F/SGW-F | | PGW-F/SGW-F |
+--------------+ +--------------+ +--------------+
^ ^ v
^ ^ v
+---------+ +---------+ +---------+
| MN | | MN | | MN |
+---------+ +---------+ +---------+
Figure 1: Network function virtualization deployment architecture
In this architecture, the mobile core include MME and PGW-F is
located in the cloud data center, which can be the operator's
private cloud using NFV. The access network cantains PGW-F/SGW-F is
connected through an IP transit network. The PGW-F/SGW-F may also
implement by NFV of small data center in convergence layer. The
architecture of NFV based Mobile Core is shown in Figure 2.
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--------------------------------- -------------------
| ----------------------------- | | MANO LAYER |
| | OSS/BSS LAYER | | | |
| ----------------------------- | | ------------- |
| | | | |Orchestrator| |
| ----------------------------- | | ------------- |
| | VNF LAYER | | | | |
| | --------- ------ | | | ------------- |
| | |P/SGW-C| | MME | | |-----| | VNFM | |
| | --------- ------ | | ------------- |
| ----------------------------- | | | |
| | | | | |
| ----------------------------- | | ------------- |
| | NFVI LAYER | |-----| | VIM | |
| ----------------------------- | | ------------- |
--------------------------------- -------------------
Figure 2: NFV based Mobile Core Architecture
In Figure 2, the MANO layer contains Orchestrator, VNFM and VIM. The
Orchestrator is in charge of top-down service and source monitor and
fulfillment. VNFM is incharge of manage the VNFs. And VIM normally is
the Openstack which provide management of the whole virtualization
layer.
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.
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
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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.
Access network controller Core network controller
+---------+ +---------+
|LI, FM-CP| |LI, FM-CP|
+---------+ +---------+
+-------+ +-------+ +-------+ +-------+
| FM-DP | | FM-DP | | FM-DP | | FM-DP |
+-------+ +-------+ +-------+ +-------+
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Figure 2: Mobility management functions with data plane - control
plane separation with separate control in core and in access
networks.
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4.4. NFV based deployment architecture
Here is the deployment architecture in NFV.
------------- ------------
| Yang Model | | Tosca Model|
------------- ------------
-------------------------------------------------------------------------
| [VNFO] -------------------------------------------------- |
| ------------ | -------------------- ------------------------ ||
| | NBI | | | ----- ----- ----- | | ---------------------- |||
| ------------ | | |NSD| |FGD| |VLD| | ||VNFD(LI,FM-CP)(FD-DP) ||||
| | | ----- ----- ----- | | ---------------------- |||
| ------------ | -------------------- ------------------------ ||
| | API Router| | DataBase ||
| ------------ ---------------------------------------------------|
| |
| ------------ |
| |Core Engine| |
| ------------ |
-------------------------------------------------------------------------
------------ ------------ ------------
|VNFM Driver| |VIM Driver| |PNF Driver|
------------ ------------ ------------
---------------------------------------------- -----------------
| [VNFM] | |[PNF] |
| VNF Life cycle management; | | ------------ |
| VNF configuration; | | | OVS | |
| VNF update; | | ------------ |
| VNF status monitor; | -----------------
| VNF Auto healing/Scale in/Scale out |
----------------------------------------------
-----------------------------------------------------------------
| Vim |
-----------------------------------------------------------------
--------------------------------------------------
|[VNF] LI Slicing ; FM-CP Slicing; FD-DP Slicing |
--------------------------------------------------
Figure 3 Deployment architecture
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5. SIPTO deployment scenario
The Second 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. Figure 3 shows the
architecture of SIPTO.
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+---------+
| GGSN |
+---------+
|
|
------------------------------------------
| | | |
+---------+ +---------+ +---------+ +---------+
| MSC | | SGSN | | MSC | | SGSN |
+---------+ +---------+ +---------+ +---------+
| | | | | |
------------ ---------- ---------
| | |
<<<<<<<<<| <<<<<<<| |>>>>>>>>
+---------+ +---------+ +---------+
| GGSN | | GGSN | | GGSN |
| RNC | | RNC | | RNC |
+---------+ +---------+ +---------+
^| |^ ^|
^| |^ ^|
--------------- |^ ^|
^| |^ |^ ^|
+---------+ +---------+ +---------+ +---------+
| NodeB | | NodeB | | NodeB | | NodeB |
+---------+ +---------+ +---------+ +---------+
^| ^| ^|
+---------+ +---------+ +---------+
| Terminal| -> | Terminal| -> -> | Terminal|
+---------+ +---------+ +---------+ Figure 4 SIPTO Scenario
6. WLAN deployment scenario
The Third deployment scenario is the WLAN scenario. DMM can enable
the AC in the cloud. The cloud AC and maintain the authentication
and connection status. As the terminal move from one AP to another,
it still can have the connection.
...........
(' ')
((( +-----------+ )))
(( | Mobile AC | )))
((( +-----------+ )))
('..............')
|
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| IP Transit Network
(.........)
( ))
( ))
( ))
(( )
(..........)
+-----------------------------------+
| | |
| | |
| | |
+----------+ +-----------+ +----------+
| AP | | AP | | AP |
+----------+ +-----------+ +----------+
| | |
+---------+ +---------+ +---------+
| Terminal| -> | Terminal| -> | Terminal|
+---------+ +---------+ +---------+
Figure 5 WLAN deployment scenario
7. Conclusion
This document discusses the deployment scenario of DMM. Three 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.
8. Security Considerations
N/A
9. IANA Considerations
N/A
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10. Normative References
[1] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[2] Crocker, D. and Overell, P.(Editors), "Augmented BNF for
Syntax Specifications: ABNF", RFC 2234, Internet Mail
Consortium and Demon Internet Ltd., November 1997.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2234] Crocker, D. and Overell, P.(Editors), "Augmented BNF for
Syntax Specifications: ABNF", RFC 2234, Internet Mail
Consortium and Demon Internet Ltd., November 1997.
[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.
11. Informative References
[3] Faber, T., Touch, J. and W. Yue, "The TIME-WAIT state in TCP
and Its Effect on Busy Servers", Proc. Infocom 1999 pp. 1573-
1583.
[Fab1999] Faber, T., Touch, J. and W. Yue, "The TIME-WAIT state in
TCP and Its Effect on Busy Servers", Proc. Infocom 1999 pp.
1573-1583.
12. Acknowledgments
This document was prepared using 2-Word-v2.0.template.dot.
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Authors' Addresses
Vic Liu
China Mobile
32 Xuanwumen West AVE, Xicheng, Beijing
Email: liuzhiheng@chinamobile.com
Dapeng Liu
Alibaba
Email: max@dotalks.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
32 Xuanwumen West AVE, Xicheng, Beijing
Email: denglingli@chinamobile.com
Xinpeng Wei
Huawei Technologies
Email: Xinpengwei@huawei.com
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