Network Technologies SDN - Software Defined Networking
In the modern world, the information technology business is placing increasing demands on the flexibility and scalability of computer networks. So, it took the AOL IT market's old-timer to attract one million customers for 9 years, Facebook took 9 months, and the online service DrawSomething took only 9 days.
With all this, it can be observed that the main trends in the development of corporate networks and data center networks are:
• the rapid growth of traffic volumes and changes in its structure towards video transmission and unified communications (UC-C);
• the need to support mobile users (BYOD) and social networks;
• high-performance clusters for processing Big Data (BIG DATA);
• virtualization to provide cloud services (Cloud Bursting).
At the same time, the network in its classical form (control via the command line and configuration files) becomes a limiting factor in the development of the computing infrastructure. Classical approaches to solving problems, for example, based on network virtualization (VLAN, VRF), do not correspond to the level of development of server and storage virtualization. Traditional networks are primarily static and do not correspond to the rapid development of modern IT business. The scalability of traditional networks does not meet the requirements of large businesses and service providers (Deutsche Telekom, Facebook, Google, Microsoft, Verizon, and Yahoo), and the distributed management of traditional network devices is too complex and inefficient. Binding to the selected network manufacturer does not guarantee support for future applications and services, so, according to rumors, the next upgrade of network equipment from Amazon had a price tag with nine zeros. As a result, there is a picture that traditional network architectures / designs become inefficient in dynamic environments.
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A new technology or approach to building information networks is needed to solve the problems listed above. This technology is and is called Software Defined Networking, or SDN for short.
By definition from Wikipedia:
A software-defined network (SDN from Software-defined Networking, also a software-defined network) is a data network in which the network management level is separated from data transfer devices and implemented programmatically, one of the forms of computing resources virtualization.
Let's decipher this definition. If we consider a modern network device (a router or a switch, it does not matter), then it, like a cake, logically consists of three components.
1. The management level is the CLI, the embedded web server or the API and management protocols. The task of this level is to provide controllability of the device.
2. The level of traffic control is different algorithms and the functional task of which is to automatically respond to changes in traffic, that is, the intelligence of the device.
3. Traffic transfer - functionality that provides physical data transfer, the level of chips and network packets.
Figure 1 Typical Network Device
What if:
• centralize traffic management by separating control from devices?
• centralize device management?
As a result, the “new” router or switch serves only the data flow (DATAPLANE traffic transmission level), it becomes simpler and, accordingly, cheaper. Of course, to completely strip the intellect of the network device does not work out, but it is enough to replace it with a simple forwarding table.
All intelligence (MANAGEMENT PLANE and CONTROL PLANE) is transferred to a separate central device called an SDN controller.
Figure 2 Logical model of SDN network devices
So we get:
• Separation of traffic transmission functions from management functions (including monitoring of both the traffic itself and the devices transmitting it)
• A single, standard, open interface between control and transfer devices (called OpenFlow)
• Centralized network management (SDN Controller)
• Virtualization of physical network resources
• Programming capabilities for both hardware (OpenFlow) and applications (API - SDN Controller)
• Faster response to network changes
• Optimize traffic transfer (L2 / 3) through more backup paths
• Easier and faster to set up networks
• Significantly reduce application deployment time
• Simplify the management of network devices
• Reduce network management costs
• Centralized application of policies, increased productivity, reduced delays leads to more effective interaction between users and applications in corporate networks and in data center networks
• Ease of Management. Manage entire networks, not network devices
• Open, standards-based protocols allow various network equipment manufacturers to interact with each other, simultaneously increasing customer choice and competition between vendors while reducing costs, accelerating innovation in both software and hardware.
• The SDN controller supports an open programming interface (API) that allows you to program it externally, creating an environment for automation and control, as well as scaling functionality for future applications.
• The application can directly request specific network requirements.
• Visibility of all network traffic by the controller
Figure 3 General SDN Architecture
As can be seen from the architecture, in addition to the classic network management by direct commands from the system administrator to the controller, the SDN controller supports the launch of network management applications on itself. What are these applications?
Each SDN application, in essence, is a network optimization interface for a specific business application (for example, Microsoft Lynk) and its main role is to change the network in real time to the current needs of the program being serviced. In the case of Microsoft Lynk, this could be, for example, a change in the QoS of the network between two telephone subscribers to transfer HD video calls in real time without delay or the creation of a VPN tunnel between the two subscribers.
Figure 4 SDN application for MS Lynk
If we consider in more detail the information flows in the SDN architecture, we can notice two main directions of information exchange: the first is between SDN applications and the second is for managing physical network devices.
Figure 5 SDN Structure and Components
The first stream received the name "north bridge", and the second "south bridge". As a “north bridge”, the protocol is based on the REST API, and the “OpenFlow” protocol has taken root as the “south bridge”.
Figure 6 Control Information Flows of the SDN Controller
Openflow is a standard protocol, is the main element of the concept of SDN which provides the controller interaction with network devices. The controller is used to manage the switch flow tables, on the basis of which a decision is made to transfer a received packet to a specific switch port. Thus, direct network connections are formed in the network with minimal data transfer delays and necessary parameters.
Accordingly, the OpenFlow switch consists of at least two components:
• flow tables;
• secure channel
Figure 7 OpenFlow flow table example
Switches with OpenFlow support are already available on the market, so in the portfolio of the leader in the development of the SDN concept - Hewlett-Packard, more than 40 switch models support OpenFlow version 1.3, respectively, are ready to act as “bricks” to build a real SDN network.
In addition to switches, Hewlett-Packard offers several models of ready-made SDN controllers and provides several ready-made SDN applications for specific business programs, such as Microsoft Lync, for free. HP also supports the active SDN developer community (sdndevcenter.hp.com), where users can share their ideas, as well as the SDN App Store, an online application store where users can download various applications to the HP VAN SDN controller with just a few clicks.
Hewlett-Packard’s interest in SDN technology is not accidental. It is believed that SDN will change the network in the same way as virtualization in the corporate server systems market did. Accordingly, SDN for Hewlett-Packard is a strategic direction, because success in this direction can provide leadership in the market, an example of this, the success of such major players in the market of network services like Amazon and Google are actively using SDN in their work.
Hewlett-Packard also believes that SDN should be based on open standards, so that everyone can participate in this. Such an open ecosystem will resume the process of introducing innovations in the field of network technologies, which has stalled over the past two decades.
Kiev, March 23-24, will be held the course HP - Cloud Computing Foundation (EXIN)
Distribution of HP solutions in Ukraine , Georgia and Tajikistan
Catalog of all solutions and services of the distributor MUK
MUK-Service - all types of IT repair: warranty, non-warranty repair, sale of spare parts, contract service
With all this, it can be observed that the main trends in the development of corporate networks and data center networks are:
• the rapid growth of traffic volumes and changes in its structure towards video transmission and unified communications (UC-C);
• the need to support mobile users (BYOD) and social networks;
• high-performance clusters for processing Big Data (BIG DATA);
• virtualization to provide cloud services (Cloud Bursting).
At the same time, the network in its classical form (control via the command line and configuration files) becomes a limiting factor in the development of the computing infrastructure. Classical approaches to solving problems, for example, based on network virtualization (VLAN, VRF), do not correspond to the level of development of server and storage virtualization. Traditional networks are primarily static and do not correspond to the rapid development of modern IT business. The scalability of traditional networks does not meet the requirements of large businesses and service providers (Deutsche Telekom, Facebook, Google, Microsoft, Verizon, and Yahoo), and the distributed management of traditional network devices is too complex and inefficient. Binding to the selected network manufacturer does not guarantee support for future applications and services, so, according to rumors, the next upgrade of network equipment from Amazon had a price tag with nine zeros. As a result, there is a picture that traditional network architectures / designs become inefficient in dynamic environments.
')
A new technology or approach to building information networks is needed to solve the problems listed above. This technology is and is called Software Defined Networking, or SDN for short.
What is SDN?
By definition from Wikipedia:
A software-defined network (SDN from Software-defined Networking, also a software-defined network) is a data network in which the network management level is separated from data transfer devices and implemented programmatically, one of the forms of computing resources virtualization.
Let's decipher this definition. If we consider a modern network device (a router or a switch, it does not matter), then it, like a cake, logically consists of three components.
1. The management level is the CLI, the embedded web server or the API and management protocols. The task of this level is to provide controllability of the device.
2. The level of traffic control is different algorithms and the functional task of which is to automatically respond to changes in traffic, that is, the intelligence of the device.
3. Traffic transfer - functionality that provides physical data transfer, the level of chips and network packets.
Figure 1 Typical Network Device
What if:
• centralize traffic management by separating control from devices?
• centralize device management?
As a result, the “new” router or switch serves only the data flow (DATAPLANE traffic transmission level), it becomes simpler and, accordingly, cheaper. Of course, to completely strip the intellect of the network device does not work out, but it is enough to replace it with a simple forwarding table.
All intelligence (MANAGEMENT PLANE and CONTROL PLANE) is transferred to a separate central device called an SDN controller.
Figure 2 Logical model of SDN network devices
So we get:
• Separation of traffic transmission functions from management functions (including monitoring of both the traffic itself and the devices transmitting it)
• A single, standard, open interface between control and transfer devices (called OpenFlow)
• Centralized network management (SDN Controller)
• Virtualization of physical network resources
• Programming capabilities for both hardware (OpenFlow) and applications (API - SDN Controller)
• Faster response to network changes
• Optimize traffic transfer (L2 / 3) through more backup paths
• Easier and faster to set up networks
• Significantly reduce application deployment time
• Simplify the management of network devices
• Reduce network management costs
• Centralized application of policies, increased productivity, reduced delays leads to more effective interaction between users and applications in corporate networks and in data center networks
• Ease of Management. Manage entire networks, not network devices
• Open, standards-based protocols allow various network equipment manufacturers to interact with each other, simultaneously increasing customer choice and competition between vendors while reducing costs, accelerating innovation in both software and hardware.
• The SDN controller supports an open programming interface (API) that allows you to program it externally, creating an environment for automation and control, as well as scaling functionality for future applications.
• The application can directly request specific network requirements.
• Visibility of all network traffic by the controller
Figure 3 General SDN Architecture
As can be seen from the architecture, in addition to the classic network management by direct commands from the system administrator to the controller, the SDN controller supports the launch of network management applications on itself. What are these applications?
Each SDN application, in essence, is a network optimization interface for a specific business application (for example, Microsoft Lynk) and its main role is to change the network in real time to the current needs of the program being serviced. In the case of Microsoft Lynk, this could be, for example, a change in the QoS of the network between two telephone subscribers to transfer HD video calls in real time without delay or the creation of a VPN tunnel between the two subscribers.
Figure 4 SDN application for MS Lynk
If we consider in more detail the information flows in the SDN architecture, we can notice two main directions of information exchange: the first is between SDN applications and the second is for managing physical network devices.
Figure 5 SDN Structure and Components
The first stream received the name "north bridge", and the second "south bridge". As a “north bridge”, the protocol is based on the REST API, and the “OpenFlow” protocol has taken root as the “south bridge”.
Figure 6 Control Information Flows of the SDN Controller
What is OpenFlow?
Openflow is a standard protocol, is the main element of the concept of SDN which provides the controller interaction with network devices. The controller is used to manage the switch flow tables, on the basis of which a decision is made to transfer a received packet to a specific switch port. Thus, direct network connections are formed in the network with minimal data transfer delays and necessary parameters.
Accordingly, the OpenFlow switch consists of at least two components:
• flow tables;
• secure channel
Figure 7 OpenFlow flow table example
Switches with OpenFlow support are already available on the market, so in the portfolio of the leader in the development of the SDN concept - Hewlett-Packard, more than 40 switch models support OpenFlow version 1.3, respectively, are ready to act as “bricks” to build a real SDN network.
In addition to switches, Hewlett-Packard offers several models of ready-made SDN controllers and provides several ready-made SDN applications for specific business programs, such as Microsoft Lync, for free. HP also supports the active SDN developer community (sdndevcenter.hp.com), where users can share their ideas, as well as the SDN App Store, an online application store where users can download various applications to the HP VAN SDN controller with just a few clicks.
Hewlett-Packard’s interest in SDN technology is not accidental. It is believed that SDN will change the network in the same way as virtualization in the corporate server systems market did. Accordingly, SDN for Hewlett-Packard is a strategic direction, because success in this direction can provide leadership in the market, an example of this, the success of such major players in the market of network services like Amazon and Google are actively using SDN in their work.
Hewlett-Packard also believes that SDN should be based on open standards, so that everyone can participate in this. Such an open ecosystem will resume the process of introducing innovations in the field of network technologies, which has stalled over the past two decades.
Kiev, March 23-24, will be held the course HP - Cloud Computing Foundation (EXIN)
Distribution of HP solutions in Ukraine , Georgia and Tajikistan
Catalog of all solutions and services of the distributor MUK
MUK-Service - all types of IT repair: warranty, non-warranty repair, sale of spare parts, contract service
Source: https://habr.com/ru/post/251959/
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