Internet DRAFT - draft-liu-i2rs-architecture
draft-liu-i2rs-architecture
I2RS D. Liu
Internet-Draft China Mobile
Intended status: Informational B. Khasnabish
Expires: January 16, 2014 ZTE
H. Deng
China Mobile
July 15, 2013
Architecture Discussion of I2RS
draft-liu-i2rs-architecture-02
Abstract
This document discusses the high level architecture of I2RS. This
document also provides brief descriptions on the use of
virtualization and its impact on constructing chained and grouped
services. We plan to include further details on virtualization,
service chaining, and grouping in a future version of this draft.
Status of This Memo
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This Internet-Draft will expire on January 16, 2014.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions used in this document . . . . . . . . . . . . . . 3
3. Architecture of I2RS . . . . . . . . . . . . . . . . . . . . 4
4. I2RS Application/Agent . . . . . . . . . . . . . . . . . . . 5
5. I2RS Interfaces . . . . . . . . . . . . . . . . . . . . . . . 6
6. Network/Service Control . . . . . . . . . . . . . . . . . . . 6
7. Management Considerations . . . . . . . . . . . . . . . . . . 7
8. Security Considerations . . . . . . . . . . . . . . . . . . . 7
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
11.1. Normative References . . . . . . . . . . . . . . . . . . 8
11.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
This document discusses the high level architecture of I2RS. As
illustrated in figure 1, the I2RS architecture is composed by three
types of building blocks. The first type of the building block is
the user of I2RS interface. The users could be network controllers,
network management functions, other user applications etc. The user
application uses the I2RS interface interacts with the routing
system. The second type of the building block is management
functions. This include configuration management function and
security management function. The configuration management function
is used to configure the I2RS interface. The security function is
used to enforce the security polices of the I2RS interface. The
third type of the building block is routing function. This build
block includes routing information base, IP forwarding table etc.
The routing information base could be accessed by the I2RS users
using the I2RS interface. Besides, the routing control and the
forwarding function could also be separated. The interface between
the routing control and forwarding function could be open flow,
ForCES etc.
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+------------------+ +------------------+ +-----------------+
|Network Controller| |Network Management| | User Application|..
+------------------+ +------------------+ +-----------------+
| | | |
\---------------| |--------------------/
| | I2RS Interface
+----------------------+ | | +------------------+
|Configuration Function|----| |-----|Security Function |
+----------------------+ | | +------------------+
| |
| | Routing Function
+---------------------------| |--------------------------------+
| | | |
| +------------+ | | +-----------+ |
| |OSPF process| | | |BGP process| ... |
| +------------+ | | +-----------+ |
| | +--------+ | |
| | | Agent | | |
| | +--------+ | |
| | +----------|-------------+ | |
| +-----|Routing Information Base|-------+ |
| +------------------------+ |
| | |
+---------------------------|----------------------------------+
|
{OF, ForCES, .. Protocol} | Forwarding Function
+---------------------------|----------------------------------+
| | |
| | |
| +--------------------+ |
| | IP Forwarding Table| |
| +--------------------+ |
| |
+--------------------------------------------------------------+
Figure 1: architecture of I2RS
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 RFC-2119 [RFC2119].
In this document, these words will appear with that interpretation
only when in ALL CAPS. Lower case uses of these words are not to be
interpreted as carrying RFC-2119 significance.
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A list of acronyms and abbreviations used in this document are
presented below.
o ForCES: Forwarding and Control Element separation
o I2RS: Interface to Routing System
o NF: Network Function
o NSC: Network Service Chaining
o NSG: Network Service Grouping
o OF: Open Flow
o RIB: Routing Information Base
o SF: Service Function
o TIB: Topology Information Base
o VF: Virtualized Function
o VNF: Virtualized Network Function
o VSF: Virtualized Service Function
3. Architecture of I2RS
This section discusses the function of the building block of the I2RS
architecture. These functional building blocks could be either
physical or virtual or hybrid, i.e., a combination of physical and
virtual blocks.
i. I2RS application
The I2RS applications communicate with the I2RS agent using the I2RS
interface. The I2RS agent locates in the router that implement the
I2RS interface. The I2RS agent communicates with the routing system.
The interface between the I2RS agent and the routing system could be
implementation specific. The I2RS application can read the routing
information from the routing information base, it can also inject
polices, routing information etc into the routing information base.
The I2RS interface could be RESTful API or websocket etc. There
should be an authentication mechanism in the I2RS architecture that
only allow the authorized application communicate with the I2RS
agent.
ii. Configuration function
The I2RS interface could be configured by the configuration function.
The I2RS user application could customize the I2RS interface function
and set the I2RS interface parameters by the configuration function.
The network administrator can also use this configuration function to
control the I2RS interface parameters. For example, the network
administrator may need to control a certain scope of the routing
information could be accessed by a specific I2RS application. The
network administrator can use the configuration function to implement
those settings.
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Virtualization of the configuration function through appropriate
management and/or visor function would help achieve (a) efficient
management of configuration resources, and (b) desired chaining/
grouping of the resources for dynamically balancing/distributing
operational loads.
iii. Security function
Security function is an important building block of the I2RS
architecture. It will ensure only authorized application can use the
I2RS interface and communicate with the routing system. There could
be different level of authorization. For example, the security
function can allow some application only read from the routing system
while other application can both read and inject polices into the
routing system.
Virtualization of the security function would help move the service
closer to the utilization point based on the desired requirements
without moving the physical device (or installing new purpose-built
devices).
iv. Routing function
The routing function is composed of routing information base (RIB),
IP forwarding table and the routing processes. The I2RS application
could communicate with the routing information base using the I2RS
interface. The agent function locates in the router could
communicate with the routing information base and the I2RS
application. It receives the I2RS application's request and convert
it to the implementation specific command to get/set the routing
information base. By this way, the I2RS application can read or
inject routing information into the routing information base. The
routing processes can also inject routing information into the
routing information base. There should be a protection mechanism to
prevent any race condition of the routing information base be
modified by different entities simultaneously. The Routing function
can be virtualized.
iv. Forwarding function
The forwarding function facilitates forwarding of flows/packets. It
can operate using simple Table or sophisticated dynamic matrix for
intelligent processing of flows. The forwarding function can be
virtualized.
4. I2RS Application/Agent
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This section discusses the I2RS application and agent function in the
architecture. There are many applications can use the I2RS
interfaces. For example, network management application can use I2RS
interface to get the network topology information. I2RS agent
locates in the routing function and communicates with the I2RS
application. The I2RS agent locates in the router, it can
communicate with the I2RS application using the I2RS interface. The
I2RS agent convert the I2RS application's command into implementation
specific functions to get/set the routing information base.
5. I2RS Interfaces
This section discusses the I2RS interfaces in the architecture. The
I2RS interface is the interface between the I2RS application and the
I2RS agent. The requirement of the I2RS interface includes the
following aspects: (1) The I2RS interface should support multiplexing
function that allows multiple I2RS applications communicate with one
I2RS agent and one I2RS application communicates with multiple I2RS
agents. (2) The I2RS interface should support authentication/
authorization mechanism that allow only the authorized I2RS
application access specific routing information. The I2RS interface
should support encryption and data integrity protection mechanism.
(3) The I2RS interface should support data protection mechanism to
prevent the race condition. (4) The I2RS interface should provide
scalability and extensibility.
6. Network/Service Control
This section discusses the network and service control in the
architecture. Network control may include control of both virtual
and physical network entities. The services may include chaining of
network services (NSCs) and grouping network services (NSGs).
^
._._._._._._._._._._._._._._ |
| ---|----------------
------- ------- |Control/Managemnt |
<- |VNF-1| <- |VNF-n|._._._._| of VNFs |-->
| | ... | | | |
------- ------- --------------------
|.............|
|
|
/----------------\
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| Virtualization/ |
| Abstraction |
\----------------/
|
|
...................
: Network :
: Function (NF) :
:.................:
Figure 2: Network Function Service Chaining
^
._._._._._._._._._._._._._._ |
| ---|----------------
------- ------- |Control/Managemnt |
<- |VSF-1| <- |VSF-n|._._._._| of VSFs |-->
| | ... | | | |
------- ------- --------------------
|.............|
|
|
/----------------\
| Virtualization/ |
| Abstraction |
\----------------/
|
|
...................
: Service :
: Function (SF) :
:.................:
Figure 3: Service Function Service Chaining
7. Management Considerations
This section discusses the management consideration of the
architecture. In addition to managing the configurations of the
virtual and physical network entities, this may include managing
service-specific meta-data and configurations of the hosts that
provide network-based value-added services like policy, compliance,
load-balancing, and so on.
8. Security Considerations
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Security function is very important for the I2RS architecture. It
should provide authentication mechanism and data protection mechanism
to protect critical routing information.
9. IANA Considerations
To be determined later.
10. Acknowledgments
.
11. References
11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
11.2. Informative References
[DMTF-DSP0243]
, "DMTF DSP0243, Open Virtualization Format Specification
2.0", December 2012.
[DMTF-DSP0263]
, "DMTF DSP0263, Cloud Infrastructure Management Interface
(CIMI) Model and REST Interface over HTTP 1.0", September
2012.
[DMTF-DSP2029]
, "DMTF DSP2029, Cloud Management for Communications
Service Providers 1.0", January 2012.
[DMTF-DSP2034]
, "DMTF DSP2034, Network Services Management Use Cases,
1.0a", March 2013.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", RFC 4271, January 2006.
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Authors' Addresses
Dapeng Liu
China Mobile
Unit2, 28 Xuanwumenxi Ave,Xuanwu District
Beijing 100053
China
Email: liudapeng@chinamobile.com
Bhumip Khasnabish
ZTE
55 Madison Avenue, Suite 160
Morristown, New Jersey 07960
USA
Phone: +001-781-752-8003
Email: vumip1@gmail.com, bhumip.khasnabish@zteusa.com
Hui Deng
China Mobile
Unit2, 28 Xuanwumenxi Ave,Xuanwu District
Beijing 100053
China
Email: denghui@chinamobile.com
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