Internet DRAFT - draft-suzuki-ndrs-requirements
draft-suzuki-ndrs-requirements
Network Working Group T. Suzuki
Internet-Draft Hitachi, Ltd.
Intended status: Informational February 14, 2014
Expires: August 18, 2014
Requirements for a Network Disaster Recovery System
draft-suzuki-ndrs-requirements-00
Abstract
Requirements concerning a network disaster recovery system such as a
wide area network management system based on Software Defined
Networking (SDN) architecture are presented. Specifically, a multi-
layer network management system, which is composed of multiple
network layers, layer management functions to manage each network
layer, and integrated-layer management, is focused on. The problems
that need to be overcome in order to consistently manage dmake the
system are presented. The requirements that should be satisfied in
order to solve these problems are presented.
Status of this Memo
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This Internet-Draft will expire on August 18, 2014.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 4
3. Use Case . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Wide Area Network Disaster Recovery . . . . . . . . . . . 5
3.2. Management System Structure (Type I) . . . . . . . . . . . 5
3.3. Management System Structure (Type II) . . . . . . . . . . 6
4. Requirement . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. Requirement for Interface of Type-I System . . . . . . . . 7
4.2. Requirement for Interface of Type-II System . . . . . . . 7
5. Security Considerations . . . . . . . . . . . . . . . . . . . 8
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
7. Informative References . . . . . . . . . . . . . . . . . . . . 10
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 11
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1. Introduction
This draft describes the requirements that a multi-layer network
management system for a disaster recovery should satisfy. An example
of the network management system is a Software Defined Networking
(SDN) system.
Recently, the SDN system has been attracting lots of attention. For
example, the SDN system has logically centralized architecture and is
expected to make the entire network resource more efficient. In
addition, it is also expected to reduce operating cost by creating an
automatic network managing function. It is also expected to manage
the network to provide high quality data transmission such as low
latency and low jitter, or to provide efficient usage of network
resource such as bandwidth and so forth.
Under the above circumstances, the requirements concerning a network
disaster recovery system to manage the network to become highly
reliable are described in this draft. The network disaster recovery
system is created by controlling multiple network management
functions for each network layer in a coordinated manner.
Specifically, multi-layer network is managed on the basis of
cooperation between the lower-layer network management functions and
the upper-layer network management functions. The requirements
concerning the multi-layer network management for the network
disaster recovery are described here while the requirements for other
functions have been discussed in many groups including SDN [SDN]
research group.
In section 2, specific issues on the multi-layer network management
for the network disaster recovery are discussed. In section 3, use
cases for a multi-layer network management system are described. In
section 4, requirements that the system should satisfy are
prescribed.
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2. Problem Statement
One way to create a network disaster recovery system for a network
composed of multiple layers is to create a large management function
that can control multiple network layers. However, if there is only
one network management function or server to manage a large network
composed of multiple layers and/or domains, it might become a huge
network management object. To avoid such issue, it is better to
create a management function for a large scale network by combining
multiple network management components.
In regard to a conventional network management system, there is a
network management function or server for each network layer or
domain. Therefore, if multiple network management functions execute
their recovery procedures independently, they might be executed
inconsistently. For example, if the upper-layer management tries to
recover by using routing protocol or policy routing etc. in
accordance with an old network topology when the lower-layer
management changes the lower-layer topology to recover from a network
disaster, the upper-layer data will not be transmitted under the
recovered new topology. In this case, the upper-layer management
should try to recover in accordance with the new network topology.
Therefore, to create a network disaster recovery system for multi-
layer network under the conventional conditions, the system has to be
created by including multiple management functions for each network
layer. In addition, the multiple management functions should
cooperate to recover from a network disaster. However, a method or
protocol for communication among multiple network management
functions for each layer has not been defined yet. Specifically,
communication procedures for recovering from a network disaster have
not been defined.
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3. Use Case
3.1. Wide Area Network Disaster Recovery
One of use cases for the multi-layer network management system based
on the SDN architecture is a wide area network disaster recovery. In
case of a network disaster, many network apparatuses are severely
damaged and various network services also go down. Therefore, the
system has to recover from an out-of-service state by managing the
remaing network resources.
3.2. Management System Structure (Type I)
A target network disaster recovery system is shown in Figure 1. The
system is composed of multiple networks such as an upper-layer
network and a lower-layer network, and an upper-layer management
server, a lower-layer management server, and an integrated-layer
management server. To execute network disaster recovery, multiple
network management servers must interact in a coordinated manner.
Therefore, as shown in Figure 1, two new interfaces are needed. One
is the interface between the integrated-layer network management
server and the upper-layer network management server. The other is
the interface between the integrated-layer network management server
and the lower-layer network management server.
+-------------------------------------------------------------+
| Integrated-Layer Network Management Server |
+-------------+---------------------------+-------------------+
|(1) New I/F |(2) New I/F
+-------------+------------+ |
| Upper-Layer Network | |
| Management Server | |
+-------------+------------+ +-------+-------------------+
| | Lower-Layer Network |
| | Management Server |
| +-------+-------------------+
|Conventional I/F |Conventional I/F
_______|___________________________|_____________
_( ____________________|__ )_
_( _( )_ )_
( Upper-Layer ( Lower-Layer ) )
(_ Network (_ Network _) _)
(_ (________________________) _)
(____________________________________________________)
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Figure 1: Example of a target multi-layer network management system
3.3. Management System Structure (Type II)
Another target network disaster recovery system is shown in Figure 2.
The system is composed of multiple networks such as an upper-layer
network and a lower-layer network, and an upper-layer management
server and a lower-layer management server. To execute network
disaster recovery, multiple network management servers must interact
in a coordinated manner.
In this case, as shown in Figure 2, a new interface is needed. It is
the interface between the upper-layer network management server and
the lower-layer network management server.
+-----------------------+ +-----------------------+
| Upper-Layer Network |(3) New I/F | Lower-Layer Network |
| Management Server |------------| Management Server |
+-------------+---------+ +----+------------------+
| |
| |
| |
|Conventional I/F |Conventional I/F
_______|___________________________|_____________
_( ____________________|__ )_
_( _( )_ )_
( Upper-Layer ( Lower-Layer ) )
(_ Network (_ Network _) _)
(_ (________________________) _)
(____________________________________________________)
Figure 2: Another example of a target multi-layer network management
system
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4. Requirement
The interfaces shown in Figure 1 and Figure 2 are needed to create
the network disaster recovery system based on the schemes described
in the previous section. The requirements for each interface are
briefly described below.
4.1. Requirement for Interface of Type-I System
(1)Interface between Integrated-layer and Upper-Layer:
The first interface is used by the integrated-layer network
management server to control the upper-layer network. For
example, the integrated-layer network management server
controls timing to execute the upper-layer network disaster
recovery procedures against the lower-layer network disaster
recovery procedures. In addition, the integrated-layer network
management server uses the interface to gather information of
the lower-layer network conditions such as a topology and
provides it to the upper-layer network management server.
(2)Interface between Integrated-layer and Lower-Layer:
The second interface is used by the integrated-layer network
management server to control the lower-layer network. For
example, the integrated-layer network management server
controls timing to execute the lower-layer network disaster
recovery procedures against the upper-layer network disaster
recovery procedures. In addition, the integrated-layer network
management server uses the interface to gather information of
the upper-layer network conditions such as a topology and
provides it to the lower-layer network management server.
4.2. Requirement for Interface of Type-II System
(3) Interface between Upper-layer and Lower-layer:
The third interface is used by the upper-layer network
management server and the lower-layer network management
server. For example, the lower-layer network management server
requests the upper-layer network management server not to start
the network disaster recovery procedures while the lower-layer
disaster recovery procedures are executed.
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5. Security Considerations
This document describes problems and requirements for a network
disaster recovery system. The system might be composed of multiple
management functions to manage each network layer and each management
function might be implemented in a different computational equipment.
To achieve network disaster recovery in a coordinated manner by using
multiple management functions, it is necessary to exchange
information between them. It is therefore necessary to use a secure
communication channel between the management functions.
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6. IANA Considerations
This document includes no request for IANA.
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7. Informative References
[SDN] "SDN Research Group".
<http://irtf.org/sdnrg>
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Author's Address
Toshiaki Suzuki
Central Research Laboratory, Hitachi, Ltd.
292 Yoshida-cho
Totsuka-ku, Yokohama, Kanagawa 244-0817
Japan
Phone: +81-50-3135-3066
Email: toshiaki.suzuki.cs@hitachi.com
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