Iterative DNS query

An iterative DNS query is a type of DNS query where the DNS server responds with the best answer it can find, based on the information it has available. If the DNS server does not have the requested information, it will return a referral to another DNS server that might have the information. What’s the … Read more

Field of view (FOV)

The term field of view (FOV) is used in networking to describe the maximum amount of information that can be seen by a network device when it is looking at a particular data stream. The field of view of a network device can be affected by a number of factors, including the type of device, … Read more


NetFlow is a feature that was introduced on Cisco routers that allows the router to collect information about traffic flowing through it and export that information to a NetFlow collector. The NetFlow collector can then use that information to generate reports about traffic flows, bandwidth usage, etc. Is NetFlow still used? NetFlow is a data … Read more

Northbound interface / southbound interface

The Northbound interface is the interface between the network controller and the applications that use the controller. The Southbound interface is the interface between the network controller and the devices that it controls. What is the difference between northbound and southbound? Northbound traffic refers to the data flowing from the lower layers of a network … Read more

Open Networking Foundation (ONF)

Open Networking Foundation (ONF) is a non-profit, operator-led consortium that is driving transformation of network infrastructure and carrier business models. The Open Networking Foundation leverages SDN principles and disaggregation, using open source platforms and defined standards to enable network control and orchestration across a wide variety of multi-vendor hardware and software solutions. The Open Networking … Read more


OpenFlow is a communication protocol that was designed to enable the creation of software-defined networking (SDN) solutions. It does this by allowing network administrators to directly control the flow of traffic on a network, without having to rely on proprietary hardware or software solutions. OpenFlow was originally developed by a consortium of companies, including Cisco, … Read more

CE router (customer edge router)

A customer edge router (CE router) is a router that connects a customer’s local area network (LAN) to a service provider’s network. A CE router is also known as a customer premises equipment (CPE) router. The term “customer edge router” is most commonly used in the context of Internet Protocol (IP) networks, such as the … Read more

Squid proxy server

A Squid proxy server is a web server that enables users to access web content through a web browser. Squid proxy servers are typically used to improve web performance by caching frequently accessed web content. When a user requests a web page that is cached by a Squid proxy server, the server returns the cached … Read more

Rocker switch

A rocker switch is a type of switch that is activated by pressing down on a raised portion of the switch. Rocker switches are often used to control lights or other electronic devices. What is the difference between a rocker switch and a toggle switch? Rocker switches and toggle switches are two types of switches … Read more

Segment routing

Segment routing is a type of routing that uses individual segments, or paths, to route traffic. Segment routing can be used to create custom routes for specific traffic types or to optimize routing for specific conditions. Segment routing can be used in conjunction with other routing protocols, such as Border Gateway Protocol (BGP), or it … Read more