DWDM Vs. OTN: What’s the Difference?

As we slip further in the internet era, the internet boom pushed service providers to find a method to increase the capacity on their network in the most economical way. Therefore, two technology come into our sight: DWDM vs. OTN, the technologies that can expand existing bandwidth. To learn more about them and the difference between OTN and DWDM, this article may be of some help.

DWDM Vs. OTN: DWDM Basics

What is DWDM? DWDM stands for dense wavelength division multiplexing. It is a technology to send multiple strands of data through a single network link. In the transmitting end, there is an optical multiplexer converging two or more optical signals at different wavelengths. Whereas in the receiving end, an optical demultiplexer is used to separate the signals, and in this process it is unavoidable to cause signal loss which, however, can be mitigated by the optical amplifier. DWDM connections can therefore be used for transmitting data over long distances as it can increase bandwidth over existing fiber networks.

DWDM Vs. OTN: OTN

OTN stands for optical transport network which provides a network-wide framework that adds SONET/SDH-like features like performance monitoring, fault detection, communication channels, and multiplexing hierarchy to WDM equipment. It works at Layer 1 to gather various tasks into the tunnel of WDM technology, increasing the transmission distance and capacity of fiber optics. It means that OTN frame structure combines the flexibility of SDH/SONET technology with the bandwidth expandability of DWDM, thus it can provide functionality of transport, multiplexing, routing, management, supervision, and survivability of optical channels carrying client signals.

The optical transport network is designed to deliver a transparent framework to efficiently carry diverse traffic types, which can decrease ACPEX/OPEX in networks and at the same time address dramatic shifts in traffic types. All in all, the charming of the OTN can be translated into two words: transparency and manageability.

Difference Between DWDM and OTN

DWDM is a point-to-point system while OTN, composed of optical cross-connector (OXC) and optical add/drop multiplexer (OADM), possesses functions like optical cross-ability and wavelength conversion. The OTN grows on the basis of DWDM technology with the aim of optimizing the existing resources of transportation network. In addition to providing large capacities of DWDM transmission, OTN permits the switching of different DWDM channels according to the needs of traffic.

In addition, as it has been proven that it is possible to tap a fiber optic cable and extract data streams, people have paid much more attention to data security over DWDM links. In contrast, OTN-channelized links and effective partitioning of traffic onto dedicated circuits bring a high level of privacy and security, preventing hackers who sneak in some section of the network from intercepting data or gaining access to other areas.

We can say that OTN network excels DWDM networks in its enhanced OAM, security and networking capabilities for wavelengths and standard multiplexing hierarchy and end-to-end optical transport transparency of customer traffic.

Conclusion

DWDM vs. OTN, the topic being addressed in this article, makes sense for those who want to better utilize them and is worthy of being explored further. Though there are indeed differences between OTN and DWDM, the two technologies are irreplaceable and have become the key point in the telecommunications infrastructure for regional networks as the allows bandwidth over existing networks. FS focuses on providing customers the best technical support, engineering cost effective and scalable solutions for metro and long-haul DWDM network. For more details, visit this website.

NAT: Why Do We Need It?

NAT, which is critical to the IPv4 networks we still use today, has been hotly debated as the IPv6 grows with more addresses. However, since the IPv6 is not full-fledged, the existence of NAT still makes sense. Here I will introduce NAT definition and figure how NAT works and why we need it.

What Is NAT?

NAT, known as network address translation, is the method adopted by a firewall or router to assign the public addresses to the devices work in the a private network.

It translates the private IPv4 addresses we use in our internal networks into public IPv4 addresses that can be routed over the internet. As we all know, the private addresses may be occupied by connected local service—computers, game consoles, phones, fiber switches etc. to communicate with the modem/router and other devices on the same network. However, the home network connection uses a single public IP address to access the internet. Given this, NAT is responsible for translating the IP address of every device connected to a router into a public IP address at the gateway. Then those devices can connect to the internet.

NAT: Why We Need?

Assume that you have 3 PCs, a gigabit Ethernet switch which connects 6 PCs, a 10 gigabit switch connecting 6PCs and one smart phone, two ipads and all of them need to work at the same time, then you need to get each of them an IP address accessible to the Internet. But due to a lack of IPv4 IP address space, it is hard to handle the massive number of devices we use every day. Well, the network address translation, proposed in 1994, has become a popular and necessary tool in the face of IPv4 address exhaustion by representing all internal devices as a whole with a same public address available. Together with its extension named port address translation, the network address translation can conserve IP addresses.

Safety, another issue we may concern when accessing the external internet, can partly be addressed by network address translation which servers as a strict controller of accessing to resources on both sides on the firewall. The hackers from outside cannot directly attack the internal network while the internal information cannot access the outside world casually.

How Does NAT Work

A router carrying NAT consists of pairs of local IP addresses and globally unique addresses, by translating the local IP addresses to global address for outgoing traffic and vice versa for incoming traffic. All these are done by rewriting the headers of data packets so that they have the correct IP address to reach the proper destination.

There are generally two types of NAT: dynamic and static.

In dynamic NAT, we map inside local addresses in internal network to global addresses so that they can access resources on the internet. The router responds to the hosts who want to access the internet with an available public IPv4 address so that they can access the internet.

In static NAT, we usually map an internal local address to a global address so that hosts on public networks can access a device in the internal network.

Conclusion

In a word, before the full transition of IPv6, NAT can guarantee the smooth internet surfing no matter how many devices you’ve got. Knowing what it is and how it works with network address will help you establish a clear understanding of it so that you can make good use if it.

SDN vs. OpenFlow vs. OpenStack: What’s the Difference?

As the network grows, the network equipment producers flourish, bringing many different exclusive products into the market. How to manage or operate so many equipment as the different vendors own diversified CLI and web interface to debug and configure. It’s time to put forward some new technologies, SDN vs. OpenFlow vs. OpenStack to tackle this problem.

SDN VS OpenFlow vs. OpenStack: What Are They?

SDN-Software Defined Network

Software-defined networking (SDN) technology is a new way to cloud computing.To improve network monitoring and performance, SDN is designed to enhance network management and promote programmatically network configuration efficiently. It centralizes network intelligence in one network component by decoupling the forwarding process of network packets (data plane) and the routing process (control plane). SDN is mainly composed by application layer which provides application and service, control layer responsible for unified management and control, and forwarding layer that offers hardware equipment like fiber switches, Gigabit Ethernet switches and routers to forward data. The following table illustrates the advantage of SDN against traditional network.

Software-defined Network vs. Traditional Network

OpenFlow: the Enabler of SDN

To turn the concept of SND into practical implementation, we need to put into place some protocols, among which OpenFlow is the most desirable one. So what is OpenFlow?

OpenFlow is a communications protocol that empowers a network switch or router to access the forwarding plane over the network. Also it can serve as a specification of the logical structure of the network switch functions. We know that each switch vendors may have their own proprietary interfaces and scripting languages, and this protocol enables them to work coordinately while avoid exposing their technology secret inside switches to the public.

OpenStack

OpenStack is an open source cloud computing management platform project that combines several major components to accomplish specific tasks. Its existence confronts the AWS of Amazon, as it allows all participators to access the source code and share some ideas, if they want to. It is convenient and reliable with strong compatibility and adaptability, gaining support from many vendors.

SDN vs. OpenFlow vs. OpenStack: What’s the Difference?

SDN vs. OpenFlow

SDN and OpenFlow are prone to be confused and misunderstood. Take a look at SDN vs. OpenFlow, the two are indeed interconnected. First of all, as an open protocol, OpenFlow underpins the various SDN controller solutions. The complete SDN solution is taking SDN controller as the core, backed by OpenFlow switches and NFV to offer bountiful SDN app for a new smart, dynamic, open, custom network.

OpenFlow vs. OpenStack

OpenFlow, since its release, has gained achievements in hardware and software support. CISCO, Juniper, Toroki and pronto have all launched network equipment like 10gbe switch, router, and wireless access point which support OpenFlow. In contrast, OpenStack covers many aspects like network, virtualization, operation system, and server. It is an ongoing cloud computing platform.

SDN vs. OpenStack

Network orchestration OpenStack copes with the component organization of a particular group of assets, from open source or closed implementations, thus we can say that it can be considered how a software-defined network is deployed. While SDN control serves like the commander of organizers and deals with maintaining consistent (as far as is feasible) policy across multiple groups of assets, so we deem it much like the "why."

Conclusion

SDN vs. OpenFlow vs. OpenStack, the three terms that are of far-reaching significance, attract more attention from the public. This article may provide you with some help to know them at the very first step. Till now, the networking technologies are still advancing, knowing what they are at present doesn’t mean the truly master of it. There is still plenty of room left to be explored
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