Internet DRAFT - draft-aoch-nvo3-edge-datacenter
draft-aoch-nvo3-edge-datacenter
NVO3 WG T. Ao
Internet-Draft ZTE Corporation
Intended status: Standards Track Z. Chen
Expires: January 4, 2018 China Telecom
July 3, 2017
The use case in Edge Datacenter network
draft-aoch-nvo3-edge-datacenter-01.txt
Abstract
This document introduces the Edge Datacentet network, and describe
some use cases about Edge Datacenter, discusses an important
component in the Edge Datacenter:Service Gateway and its functions,
elaborates the requirements on Service Gateway.
Service Gateway works as a Flow Split Device(FSD) in the Edge DC
network, it needs to not only play a gateway of the edge Datacenter
network, implementing coordination with existing technology, but also
meets many new requirements. For example, to make sure the packets
goes into Edge DC or Metro network, SDN forwarding, and as a leaf in
the leaf-spin architecture.
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Problem statement . . . . . . . . . . . . . . . . . . . . . . 3
4. Edge Datacenter . . . . . . . . . . . . . . . . . . . . . . . 3
4.1. Use cases of the EDC . . . . . . . . . . . . . . . . . . 5
4.1.1. Future video application . . . . . . . . . . . . . . 6
4.1.2. Edge IOT control application . . . . . . . . . . . . 6
4.1.3. Home Hybird Cloud . . . . . . . . . . . . . . . . . . 7
4.1.4. Light weight lease line based on application . . . . 8
5. Service Gateway . . . . . . . . . . . . . . . . . . . . . . . 9
5.1. Functions . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1.1. PPPoE proxy . . . . . . . . . . . . . . . . . . . . . 9
5.1.2. VxLAN encapsulation . . . . . . . . . . . . . . . . . 9
5.1.3. C/S VLAN forwarding . . . . . . . . . . . . . . . . . 10
5.1.4. Distribution . . . . . . . . . . . . . . . . . . . . 10
6. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
9. Information References . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction
With the challenge and the chances of the new network SDN/NFV and the
development of the Datacenter, the provider is facing many changes
from traditional network, which is representive by traditional CO.
How to use the resource of the traditinal CO fully and achieve the
transition to the SDN/NFV is the problem providers and vendors need
to consider. CO re-architection is the attractive to more and more
providers and vendors. and getting more and more attention. Using
lots of CO resource, the providers can re-architected CO to Edge DC,
which is more adaptive in SDN/NFV.
In this document, we will present some use cases of the Edge
Datacenter and its main component, Service gateway. As a result,
some requirements are proposed for Edge DC and Service Gateway.
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2. Terminology
Edge DC(EDC): a Datacenter network which is close to user, may by
recontructureed from CO, and is SDN/NFV
Servie Gateway: flow split device(FSD) in the Edge Datacenter
network.
FSD(Flow Split Device): device to split user flow according to the
control flow table, include forwarding plane and stack module.
CO: Center Office.
3. Problem statement
Current network is facing some bottlenecks which also rises some
important requirements.
1.Low latency:Generally, there is more than 10ms latency between user
and application in the cloud. If we put some application requiring
low latency to network front end, low latency can be meet by this
closing to user mode.
2.Massive access: One of the bottlneck of the network is from the
increasing number of session to access to the network, and it's
difficult to meet the explosive session in current network. It is
required to adpot NFV, and to seperate the control plane and user
plane. Meanwhile, Massive IP address can be processsed at the edge
of the network in the case of IoT, so that IP address management can
also be optimized.
3.Large traffic: There will be a serious pressure in bandwidth
resource if the large traffic is transitted from the edge of the
network to the core of the network. EDC can be used for these large
traffic locally process so that some of them can be absorbed at the
edge of the network.
4. Edge Datacenter
From above section, we know that EDC(Edge Datacenter) can meet the
challenge from the low latency, Large traffic and massive sessions by
improving the capability at the edge of network and providing a cloud
architecture. The interoworking archtecture about EDC is as
Figure 1.
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**********************************
* +------+ +------+ +------+ *
* | vBNG | | vOLT | | vEPC | *
* +------+ +------+ +------+ *
* \ | / *
* \ | / *
* \ | / *
********************* * \ | / *
* * * .................. *
* * * . . * ..........
*********** * +------+ * * . DC Fabric . * . Data .
* * * | | * * .................. * . Center .
* Mobile *----*--+ OLT +-\ * * | * ..........
* Accesss * * | | \ * * | * |
* * * +------+ \ * * +-----+-------+ * |
*********** * \ Aggregation * | | * +----+
* +---*--------*---+ Flow +--------------*---| CR |
*********** * / * * | Split Device| * +----+
* * * +------+ / * * | (FSD) | * |
* Fix * * | | / * * +-------------+ * |
* Access *----*--+ OLT +-/ * * * ............
* * * | | * * Edge DC * . Internet .
*********** * +------+ * ********************************** ............
* *
*********************
Figure 1
Considering there are many communication COs which have lots of
traditional dedicated devices in providers network, with the
evoluation of SDN/NFV, Edge Datacenter can be developed based on the
CO. An example of Edge Datacenter is showed as Figure 1. In the
Edge Datacenter, general server can be used as network element.
Virtual network elements includes vBNG,vCPE,vOLT, etc. And in
generally, the Edge Datacenter uses leaf-spin topology. There are
three types of leaf: Distribution leaf, Server leaf and Board leaf.
Server leaf is connecting Server. Board leaf is the DGW providing DC
interconnection. Distribution leaf is the SGW in Figure 2. As a key
node in the Edge datacenter, Service Gateway will be elaborated in
the next section.
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......
....( )....
. .
+->. Metro Network . .....
| ....( ).... ...( )...
| ...... . DCI .
| ...( )...
| .....
| ^
| |
********************************************************************
* | | *
* | +---------+ +---------+ | *
* | | | | | | *
* | | spin | | spin | | *
* | +---------+ +---------+ | *
* | / \ / \ | *
* | / \ / \ | *
* | / \ / \ | *
* +---------+ +---------+ +---------+ +-----+---+ *
--------------->| SGW |----| |----| |----| DGW | *
* | (leaf) | | leaf | | leaf | | (leaf) | *
* +---------+ +---------+ +---------+ +---------+ *
* | | | | *
* +------------------------------------------------------+ *
* | | *
* | VNF(vCPE, vBNG...) | *
* +------------------------------------------------------+ *
* Edge Datacenter(EDC) *
********************************************************************
Figure 2
4.1. Use cases of the EDC
EDC is in the place that is closest to user. It may not have a large
scale, but because of its "edge" propoerty, it can meet most access
requirements from user.These EDCs can get realtime data update
through WAN and core DC. By the EDC, we can not only avoid to
tranmit lots of duplicated data, but also let the users get the same
service and data as same as from core DC, but with better experience.
In this section, we will list 4 use cases of the EDC to make it
clear.
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4.1.1. Future video application
In this use case, all the video traffic are getted from EDC so that
the users can get better experience when they play games or watch
video,etc. EDC has the capability of abstract for elephant
traffic(IPTV), and support the extremely low latency video
application. Figure 3 is the diagram of this case.
+-------------+
| |
| EDC |
+-------------+
^
VR,AR,8K |
|
+-----------+
VR,AR,8k----------------------->| |
Internet----------------------->|Service GW |------------->Internet
+-----------+
Figure 3
4.1.2. Edge IOT control application
EDC has its own computational capbility, and getting more and more
intelligent. In the case that UAV( UnmannedAerialVehicle ), it needs
to communicate with the apps in EDC so that the UAV can be remote
controlled. Similar with other IOT control scenarios. Figure 4 is
the diagram of this case.
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+-------------------+
| |
| APP |
+-------------------+
/ \ Dynamical deploy
/ \
|/_ _\|
+---------------+ +---------------+
| EDC | | EDC |
| (App) | | (App) |
+---------------+ +---------------+
^ ^
| Control flow |
+---------------+ +---------------+
| Service GW | | Service GW |
| |--- | |---+--------->Internet
+---------------+ | +---------------+ |
^ | ^ |
| +-----------------|-----------+
| |
+---+ +---+
|UVA|------------------------->|UVA|
+---+ Fly to... +---+
Figure 4
4.1.3. Home Hybird Cloud
In this case, EDC is an extension of Home Gateway. Some expanded
computation or expanded store are extended into EDC instead of on
HGW. Even some APPs can also extened into EDC. Users can get more
applications, such as OTT white box, remote download, and remote
desktop, etc. Figure 5 is the diagram of this case.
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+------------------------+
| |
| EDC |
| (Expanded computation) |
| (Expaned store) |
| |
+------------------------+
^
+--------------+ |
APP1------------>| | |
APP2------------>| HGW | +-------------+
PC..............>| (Computation)|------------>| |
| (store) |............>| Service GW |...............>Internet
+--------------+ +-------------+
Figure 5
4.1.4. Light weight lease line based on application
In this use case, EDC is a control node for user 2/3 layer lease line
(VxLAN or MPLS). It can support dynamically setup the tunnel
according to application identification; support user private IP
address or address management, etc. Figure 6 is the diagram of this
case.
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+-----------+ +------------+ L2/3 lease line +------------------+
| | | |----------------->| |
| User GW |------------>| Service GW |-------+ | EDC |
+-----------+ +------------+ | | (Authentication) |
| | |
| | (DHCP) |
+-----------+ +------------+ | | |
| | | |-------|--------->| (Tunnel |
| User GW |------------>| Service GW |-----+ | | management) |
+-----------+ +------------+ | | | |
| | | (User Apps) |
| | | |
+-----------+ +------------+ | | | ..... |
| | | |-----|-|--------->| |
| User GW |------------>| Service GW |---+ | | | |
+-----------+ +------------+ | | | +------------------+
| | |
| | +------------------->
| +---------------------> Internet
+----------------------->
Figure 6
5. Service Gateway
From those use case above, we know that Service Gateway as a key node
in the forwarding plane, is a flow distribution device in Edge DC
network. It needs not only to support currently existing protocols,
but aslo to meet all kinds of new requirements, ie. SDN forwarding,
virtualization,SDN control, and spine-leaf network architecture,
dynamic SFC, etc. The main purpose of the Service Gateway is to
improve the forwarding, and converge or distribute traffic according
to different service. By the Service Gateway, we can avoid the
hairpin of the traffic to Metro network, and divide the traffic into
north-south traffic and south-east traffic clearly.
5.1. Functions
5.1.1. PPPoE proxy
To terminate PPPoE tunnel.
5.1.2. VxLAN encapsulation
Encapsulate the packets into Edge DC with VxLAN as VTEP. Provide
VxLAN mapping, forwarding, and interconnection with VLAN as a
gateway.
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5.1.3. C/S VLAN forwarding
Support QinQ VLAN forwarding, so that be compatible to traditional
network, and reduce the capacity of FDB.
5.1.4. Distribution
Achieve traffic distribution according to service VLAN. The
forwarding table on the SGW can be configurated by the SDN controller
with NATCONF or OFPCONFIG protocol.
Can implement linea forwarding based any field in IP header.
6. Conclusion
CO being re-architected as Edge DC is a very critical step for
provider's evolving to SDN/NFV.
7. Security Considerations
Service Gateway must have the capability of checking the validation
of user's address.
8. IANA Considerations
N/A
9. Information References
[I-D.ietf-nvo3-arch]
Black, D., Hudson, J., Kreeger, L., Lasserre, M., and T.
Narten, "An Architecture for Data Center Network
Virtualization Overlays (NVO3)", draft-ietf-nvo3-arch-08
(work in progress), September 2016.
[I-D.ietf-nvo3-use-case]
Yong, L., Dunbar, L., Toy, M., Isaac, A., and V. Manral,
"Use Cases for Data Center Network Virtualization Overlay
Networks", draft-ietf-nvo3-use-case-17 (work in progress),
February 2017.
[RFC7365] Lasserre, M., Balus, F., Morin, T., Bitar, N., and Y.
Rekhter, "Framework for Data Center (DC) Network
Virtualization", RFC 7365, DOI 10.17487/RFC7365, October
2014, <http://www.rfc-editor.org/info/rfc7365>.
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Authors' Addresses
Ting Ao
ZTE Corporation
No.889, BiBo Road
Shanghai 201203
China
Phone: +86 21 68897642
Email: ao.ting@zte.com.cn
Zhonghua Chen
China Telecom
No.1835, South PuDong Road
Shanghai 201203
China
Phone: +86 18918588897
Email: 18918588897@189.cn
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