What is SD-WAN?

The SD-WAN networking solution is committed to providing a simple and fast solution for enterprise users to provide different land network interoperability. Without public network IP and complex deployment, it can achieve remote file sharing, unified off-site office system, file server and video surveillance and other applications. need.

As a popular concept, SD-WAN has frequently appeared in our field of vision in recent years.

The people said that it is one of the most developed communication technologies in the future and has a very commercial value.
Puctoring equipment and operators in the industry are optimistic about it. Emerging entrepreneurial companies also regard it as a rare air outlet opportunity and rush to it.
So what exactly is SD-WAN? What is it for? What's more special? Today, I will let Xiao Zaojun come to make a comprehensive analysis for everyone.
sd-wan, the full name is Software-Defined Wan, software definition of wide area network. WAN, Wide Area Network, WAN.
I believe that if students who often come into contact with IT and communication, they must not be unfamiliar with the prefix "SD (Software-Defined)". Yes, in the era when this software is king, conceptual nouns such as SDN, SDS, SDR ... have been filled with our work and become popular vocabulary.
sdn: Software Defined Network, software definition network
sds: Software defined storage, software definition storage
sdr: Software defined Radio, software definition radio
Xiaozaojunjun's previous article, I repeatedly mentioned SDN (software definition network). I said that SDN/NFV is the development direction of the future network and the significant feature of the 5G era.
SD-WAN is an important branch of SDN, which is the application of SDN technology in the field of WAN.
simply speaking, SD-WAN is SDN WAN.
w What is WAN (WAN)?
Is start with the most basic concept of WAN.
This children's shoes that are engaged in the network should know that WAN is a wide area network, and as opposite to WAN is the familiar LAN (Local Area Network, LAN).
The Wi-Fi network, Internet cafe network, and small-scale networks in the company's office, which is LAN LAN.
LAN LAN
and WAN is a more geographical computer network, which spans provinces, municipalities, and even intercontinental.
For example, the headquarters of a group company is located in Beijing, and the branch is in Shanghai, Guangzhou, and Chengdu. Then, the local network of the branch can be regarded as a local area network. The network of the entire group company is a wide area network.
WAN WAN
Note: In fact, in addition to the LAN and WAN, there is also an area network, which is a city -scale network, which is often mentioned in the operator.
The reason why there is a wide area network is that everyone should understand -the era of digital and networked, the company's operations are no longer separated from computers and various information systems and platforms.
In basic emails to office automation (attendance system, financial system, etc.), to PLM (product life cycle management), ERP (enterprise resource plan) and other systems related to the main business, all are urgent Need a strong support network.
The various information systems are the cornerstone of the development of modern enterprises
For most companies, they spend money to pull a proprietary network cable or fiber, and take the head office and branch company The connection of the network is an impossible thing. The amount of engineering and cost is an astronomical figure.
So there are only two options.
The first one is to connect all employees through the Internet.
The very popular nails and corporate WeChat are actually the way.
All on the public network (Internet)
It today when mobile Internet and optical fiber broadband are very developed, this method seems to be a good choice. However, in this way, you need to face two fatal problems: service quality and data security.
The 4G data business we use, and most of the optical fiber broadband access, are basically civilized communication services. The stability and reliability of this service are very poor, and they are often stuck or even dropped.
The quality of service, for small and micro enterprises, barely acceptable. But for large and medium -sized enterprises and even groups, it is not possible. For example, the system of the Beijing head office of the ICBC, and the system of the Jiangsu Branch, how can it be said slowly and slow?
In addition, exposing all business systems of the company to the Internet will also bring great hidden safety hazards and risks. Also give an example. If the Railway Corporation puts all its vehicle operation management system on the public network, do you feel relieved?
Net nails and corporate WeChat, behind it is also a very powerful security protection ability and system capacity of large Internet companies.
Therefore, using the Internet as the wide area network of its own company, only suitable for small and micro enterprise users. (Then, the small and micro enterprises do not need a wide area network.)
The second way is also the mainstream choice of current users, which is to connect with the special line provided by the operator.
The most representative lines are MPLS.
m What is MPLS?
mPls, Multi-ProTocol Label Switching, multi-protocol label exchange. This is an efficient and reliable network transmission technology. In simple terms, it is a label on the data stream. It is a bit like a feathers and tells all the equipment along the road: "Who am I, where am I going."
MPLS dedicated line is a special line service -based service line based on MPLS technology.
MPLS dedicated line
MPLS dedicated line is a rental service, and its ownership belongs to the telecommunications operator. The operator leases the dedicated line to you, and then promises the SLA (Service Level Agreement, service level protocol, including bandwidth, delay, jitter, packet loss rate, etc.). As for your software, it is not fast to use, it is completely ignored.
It is like the broadband installed in your home, the operator will only show you the speed -whether there are 100Mbps? Yes, that's OK. Do you play chicken? Sorry, it's not me. This is the SLA -based service.
Anyway, anyway, it is the root line, and the network quality of MPLS is still good.
The question is here again. You rent me and rent everyone. The operator's physical network is just one. The business of so many companies runs on it. How to ensure distinction and isolation?
Here, we must mention a noun that everyone is familiar with -VPN.
vpn, Virtual Private Network, virtual special network. In fact, on the basis of normal physical connections, a dedicated channel is virtual to ensure the isolation and confidentiality of communication.
vpn channel
Depending on the different networks, VPN usually includes IPSEC-VPN and MPLS-VPN.
iPSEC-VPN, VPN based on Internet. Everyone usually uses this. The employees of large companies will allocate VPNs, and then they are equivalent to becoming a company's inner network and access to the inner network.
MPLS-VPN, VPN based on operator MPLS special network. Between the entire branch and headquarters, through this connection, it is logically equivalent to everyone in an internal network.
It, let's talk briefly about the two concepts of Overlay and Underlay that you may often see. Literally, Overlay is above Lay (layer), and Underlay is below the layer. HOHO, in fact, everyone understands a picture -
The location of the packaging is different
MPLS technology. From CISCO Cisco in 1996, it has begun to sprout Tag/Label Switching. So far, it has dominated the enterprise network market for more than 20 years. There are no major improvements during the period.
Relative to Internet, the advantages of MPLS dedicated lines are relatively stable and reliable, and there is a certain guarantee for security. However, with the development of the times, its disadvantages are becoming more and more obvious, and it is highly voiced by users:
1. The cost of use is high.
has always been a dedicated line or VPN service, the prices of operators are very expensive.
For example, the price of MPLS-VPN, a transnational 10M of a provincial telecommunications, is 80,000 yuan/month. For a large group of enterprise users, there are many branches and offices. The cost of spending on special lines every year may be as high as tens of millions or even hundreds of millions of RMB.
The cost of this level is unimaginable by our family users of hundreds of dollars in the gigabit month. With the intensification of competition, this huge cost pressure is enough to make the company's CEO/CFO/CIOs difficult to settle in the throat and sleep.
2, the deployment cycle is long.
Is to apply for the installation line, the operator should take the process within the process, and it is necessary to manually come to the door for terminal installation and configuration. The entire installation time cycle is very long, usually a week to one month.
For corporate operations with increasing rhythms now, this time cycle is also unbearable.
3, difficulty in investigation.
The dedicated line network belongs to the "black box network". For corporate users, when there is a problem with the special line, it is difficult to quickly judge the cause. Enterprise IT engineers can only investigate the internal firewalls, switches, routers and other equipment in the enterprise. If the problem is not found, then help the operator.
For operators, the investigation problem is also tangled. It is often found that there is no problem in the end, and the problem is still on the user side.
In this time, it delayed a lot of time and affected the normal operation of the company's business.
4. Maintaining human tightness.
For enterprise headquarters, there are generally special IT engineers to maintain. However, for branches or offices, for cost considerations, special IT engineers are generally not equipped. In this way, the maintenance of the MPLS dedicated line has brought difficulties, and the cost has increased the cost.
In short, the MPLS dedicated line is expensive and difficult to use, "the world is bitter MPLS for a long time"!
-sd-wan's shining appearance
Okay, finally came to the protagonist of our article today.
sd-wan is an emerging WAN wide-area network technology that appears to solve the above series of problems.
sd-wan originated from SDN. SDN's knowledge is endless, then I will not introduce it today. You only need to know that the essence of SDN technology is to centrally manage the control of the network.
Predent and control is separated
sd (software definition). It does not allow the software to replace the hardware, but to extract more hardware capabilities and hand it over to the unified software control management. To put it plainly, it is to make the hardware universal and simplified, and it becomes "stupid and cute." The software controller () has become the core of all.
What is the architecture of SD-WAN based on SDN? The word is not as good as a picture. I drew a architecture diagram according to the SD-WAN solution of a device manufacturer. Please see:
sd-WAN network architecture
Wastes can be seen that the trunk of the entire network architecture is actually the Internet and MPLS dedicated line. However, on the architecture, there is an additional SD-WAN controller. This controller is the core of SD-WAN's management control.
It at the branch node, as well as headquarters nodes, there are things like UCPE and VCPE.
cpe said before 5G introduced, Customer Premise Equipment, the industry is called "client terminal equipment". The CPE here is different from 5G CPE. 5G CPE translates the 5G signal to a Wi-Fi signal. The CPE here is an interface box that is connected to the network (it can be understood as a small router).
ucpe is Universal CPE, a general client device. VIRTUAL CPE, virtual client device.
A administrators can configure the SD-WAN controller through the application layer interface, or can also send VFW (virtual firewall, Firewall), VWOC (virtual wide area network optimization controller, WAN) function to CPE to achieve corresponding functions There is no need to buy hardware.
We combined with the network architecture and node equipment to analyze it in detail, what changes will be used to use SD-WAN:
1, the interface is eaten, the load balancing
From the perspective of the branch company , SD-WAN no longer allows only MPLS, but allows MPLS, XSDL, PON optical fiber broadband, 4G LTE, and even 5G and other connection types. CPE can support Bonding (binding) of multiple interfaces, which becomes an interface resource pool.
This with the help of software capabilities and CPEs of certain equipment vendors can identify the levels of thousands of different applications and arrange different service quality.
For example, video conferences have higher requirements for network quality, so they set priority and QOS a little higher. Text chat or something, set the first point of the level, let it use the network like LTE.
It, the dependence of corporate users has greatly reduced the MPLS dedicated line, and ordinary fiber broadband and 4G can also come in handy. The user's bandwidth utilization has increased, and the cost of traffic has decreased.
2, the key to selecting the best path
WAN WAN technology is actually the path selection. For different branches, SD-WAN can choose the best path according to the current situation and configuration strategy.
sd-wan also has the ability to load balancing to enhance the reliability of the network.
In fact, in the operator network, there are still many POP (Point-OF-PRESENCE), which helps solve the link congestion and load problems between cross-operator.
3, the deployment is simple, complete the speed of seconds
. When evaluating the deployment speed of SD-WAN, people will repeatedly mention a word called ZTP, which is Zero Touch, zero contact deployment. Simply put, it is almost plugged in.
In addition to the automatic obtaining configuration after CPE is called, it can also be configured with code configuration or mail configuration.
In the email deployment method as an example. When deploying SD-WAN, the headquarters of IT engineers only need to do the configuration data in advance, and then send the configuration to any employee of the branch through the email. The employee can complete the deployment of the device through the link.
is so convenient and fast, no longer require professional IT people to configure and install.
4, self-control and self-control, intelligent operation and maintenance
sd-wan has SDN genes, so it has innate advantages in network management. Whenever SD-WAN's management platform is visualized by graphics. The administrator can clearly see the operation of the SD-WAN through the network management interface and deal with the problems that occur in time. This greatly reduces the difficulty of maintenance, and also reduces the processing time of faults.
In short, the advantage of SD-WAN is to save money and easy to use. According to estimates, under the width of the year-on-year example, SD-WAN can save at least 30%of cost investment compared to MPLS. Therefore, some people joked that SD-WAN was "Save Dollars (Save money) -wan".
-sd-wan development
money is the last word. The return of real gold and silver promotes SD-WAN to develop at an amazing speed.
sdn was prototype in 2006 and officially named it in 2011. SDN and Wan spark the sparks for the first time in 2014.
This year, an ONUG (Open Network User Group) consulting company, which was previously an investment company, put forward a number of application scenarios of SDN technology at a seminar on the network needs of future corporate companies in the future. Therefore, SDN really met with the company's WAN network.
The on the website, there is an article on the website with an article "Software-DEFINED WAN: A Primer". The first time the name SD-WAN was introduced into the public's vision. (PRIMER has the meaning of enlightenment and entry.)
Since then, SD-WAN has quickly attracted widespread attention from the industry, and major giants have begun to support.
In 2015, SD-WAN's market revenue was only 225 million US dollars, and the application rate was less than 1%. In 2018, SD-WAN's foreign application rate has reached an amazing 40%. Industry analysis agency IDC is expected to increase by 2021 SD-WAN market size to $ 8 billion.
The enterprises engaged in SD-WAN services are divided into many categories. Let's briefly introduce it.
The first category is the company that focuses on providing wide -area network solutions. They purchase the operator's dedicated line, and then set up their own wide area network to provide SD-WAN services to business users.
The second category is traditional equipment manufacturers, such as Huawei, ZTE, Xinhua III. No need to introduce more, schemes, hardware, software, they sell everything.
The third category is companies that sell SD-WAN to sell optimization, security, encryption and other technologies and products. They have their own software and hardware products and are sold to SD-WAN users.
The traditional telecommunications operator also attaches great importance to SD-WAN, after all, it is a technology that threatens its rice bowl. At present, domestic operators have conducted SD-WAN service pilots in many places. Their business model is mainly based on existing infrastructure services, using their advantages in hardware resources to provide network value -added services. For example, firewalls, WAN acceleration and network security.
In short, SD-WAN is a wide-area network solution that can be quickly deployed, low-cost and high flexibility. It has become the mainstream trend of the industry. The only thing we pay attention to now is who will win the fierce battle around SD-WAN, who can become the biggest winner in the future wide-area network market!
(Source: Xianzao Class)