Over The Top (OTT)

OTT Service Diagram (Courtesy of  http://ottsource.com/ott-blog/)

OTT = Over-the-Top，是一種支持跨越 Internet 應用的網路服務，不同於過去一些應用服務受到運營商的控制。例如 :

• 以往的電話、簡訊必須經過電信公司提供，現在則有 OTT 方式的Skype、QQ、Line、WeChat 等。
• 以往的電視必須由無線、有線電視業者提供，或者 MOD 也必須經過電信公司，現在則有 OTT 方式的 Netflix、PPTV、PPS等。

FQDN (Fully Qualified Domain Name)

 

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FQDN (fully qualified domain name) is an unambiguous domain name that specifies the exact location of a computer within the domain's hierarchy.

The complete domain name for a specific computer, or host, on the Internet. The FQDN consists of two parts: the host name and the domain name. An example is mycomputer.mydomain.com.

A URL that consists of a host and domain name, including top-level domain. For example, www.symantec.com is a fully qualified domain name. www is the host, symantec is the second-level domain, and .com is the top-level domain. An FQDN always starts with a host name and continues to the top-level domain name, so www.sesa.symantec.com is also an FQDN.

Ref. Symantec

Power over Ethernet (PoE)

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Power over Ethernet or PoE describes any of several standardized or ad-hoc systems which pass electrical power along with data on Ethernet cabling. This allows a single cable to provide both data connection and electrical power to devices such as wireless access points or IP cameras. Unlike standards such as Universal Serial Bus which also power devices over the data cables, PoE allows long cable lengths. Power may be carried on the same conductors as the data, or it may be carried on dedicated conductors in the same cable.

Since only two of the four pairs are needed for 10BASE-T or 100BASE-TX, power may be transmitted on the unused conductors of a cable (see figure above).

Ref. Wikipedia

Port Forwarding

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Port forwarding allows remote computers (for example, computers on the Internet) to connect to a specific computer or service within a private local-area network (LAN).

CDN (Content Delivery Network)

(Left) Traditional scheme of distribution. (Right) CDN scheme of distribution.

Also known as Content Distribution Network. CDN is a large distributed system of servers deployed in multiple data centers across the Internet. The goal of a CDN is to serve content to end-users with high availability and high performance.

Ref. Wikipedia.

Introducing Z-Wave Technology

The video below is a good presentation on Z-Wave. I'll save words for now.

The IP Protocol Suite (TCP/IP)

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The Internet protocol suite is the networking model and a set of communication protocols used for the Internet and similar networks. It is commonly known as TCP/IP.

OSI 7 Layer Model

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The Open Systems Interconnection (OSI) model is a conceptual model that characterizes and standardizes the internal functions of a communication system by partitioning it into 7 abstraction layers.

Transmission Control Protocol (TCP)

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To overcome the unreliability of connectionless Internet Protocol (IP), Transmission Control Protocol (TCP) provides connection-oriented protocol that enable you to

• send longer message
• make sure your messages arrive at the destination

Internet Protocol (IP)

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The Internet Protocol (IP) is the principal communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.