Acronymopedia: API

Application Programming Interface.

APIs are a way for one program to use the functions of another program. For example, If I write a program that catalogs the name, address and phone numbers of my favorite restaurants, I can use the Google Maps API, to incorporate maps and directions to these locations. I don’t have to add the mapping functionality to my program.

Some APIs are publicly usable (like Google Maps, Twitter, etc). (here is a list of the most popular APIs).  Some APIs are just used from an internal program to another internal program.

Most SDN implementations utilize a REST (or RESTful) API. This type of API allow the programmer to use information from the network, either to see status, make changes, etc. without having to write a networking application, or dig through a database of information.

In SDN-world, APIs are divided into two groups;

Northbound – which are APIs from the Higher layer orchestration or management layer. OpenStack Neutron (the networking component of OpenStack) has an API which would be considered a northbound API (OpenStack can make changes to the network using this API).

Southbound – which are APIs to and from the actual network devices. OpenFlow is considered a southbound API, as is Cisco’s onePK.


Acronymopedia: BRAS

Broadband Remote Access Server, and the virtualized version; vBRAS.

Effectively sits at the core of the ISP’s network. Used to route DSL traffic to and from the DSLAM (digital subscriber line access multiplexer) and the Internet router(s).

DSL to Internet connectivity diagram

More information in this Wikipedia article.

Acronymopedia: BYOD

Bring Your Own Device (BYOD), is a term used to describe the trend of employees bringing their own computing devices to work. Laptops, tablets and smartphones, sometimes referred to as the “consumerism of IT”. The intent of BYOD is to enable “anywhere access” to corporate information from devices owned by the employee. Without a well thought out plan from the IT organization, BYOD can expose the corporation (and its customers) to security problems.

BYOD can also be an acronym for “Bring Your Own Destruction”, which refers to the potential chaos a poorly planned policy from corporate management and IT.

Acronymopedia: SDN

Software Defined Networking (SDN)

Generally speaking, SDN is the ability to utilize an application framework (software)  function to control the movement of network traffic through the entire network. More specifically, the idea is to separate the control plane (decision making, “brains”) of a network device, from the data plane (data movement, “braun”), and then to centralize the control plane of multiple devices under a single control point. This single control point can then be a part of a higher-level management or orchestration framework, which allows for a more holistic view of the entire infrastructure.

Other terms that may be used in congestion with SDN; abstraction, OpenFlow, OpenDaylight, Controller. Application Programming Interface


Additional Links;

Open Networking foundation

OpenDaylight Foundation

Wikipedia Article


Acronymopedia: NaaS

Network as a Service (NaaS) is a business model for offering networking services in the cloud, or on a pay-as-you-go basis. Some items that could be considered NaaS include Virtual Private Network (VPN) or Bandwidth on Demand. 


A couple of resources for more information on NaaS;  

Network as a Service Wikipedia entry

Network as a Service entry at SearchSDN

Acronymopedia: NFV

Network Functions Virtualization (NFV) is a specification (not a formal standard) from (primarily) communications industry service providers. The intent is to migrate many network functions (components) from physical appliances to virtual machine implementations.

For example, rather than having to deploy a new box for every instance of a firewall, (including rack space, power/cooling, cabling, etc), NFV prescribes the use of standardized virtual machine images (virtual appliances) to provide the required functionality. This would allow network communications providers utilize the same methodologies employed by cloud computing providers. There are many network product vendors today that deliver their products as a virtual appliance, but I am not yet sure they qualify as an “NFV” product.

The NFV specifications are maintained under the European Telecommunications Standards Institute (ETSI) Industry Specification Group (ISG). NFV is not a standard, but a specification for how networking functions will be virtualized.

NFV and SDN are closely related, but NFV does not require SDN. They are complimentary technologies. SDN can utilize NFV and vice-versa, but neither is required to have the other.

Closely related acronym; NaaS (to be defined later)

(This post has been edited to add a link to the NaaS entry)

Acronymopedia: PVID

PVID is an acronym for “Port VLAN ID”. In IBM switching products, the term PVID is used to identify the VLAN ID that is used to process traffic within the switch when the packets do not have a 802.1Q VLAN tag.

The terminology is different, but the concept is the same as other networking products.  To put this in more industry standard terms, the Port VLAN ID is the “native” or “untagged” VLAN.

When an untagged packet is received on a port on a switch, PVID tells the switch to “treat packets received on this port a belonging to this VLAN ID”.

When packets egress the switch on the port, the switch will remove (or not apply) a VLAN tag if the packet belongs in the PVID VLAN.