What is EDFA how does works and where it be used

EDFA as define erbium dipped fiber amplifier. Indian products are available in 16/4 and 16/8 and Chinese products have several models like 16/32. Here 16 consider as a DB size. We can get four outputs from 4 and 16 levels.

EDFA generally upto 0.25 , 0.3 DB loss possible at every one kilometres. Hence 16/0.3 = 53 kilometres able to send signals.ml meanwhile if put any splitters then we must calculate the DB loss in between them.

EDFA generally used in MSO's and telecommunications they used to send signal across the nation. 

What is Proxy Server where it be used

                  Proxy server as another name called cache server. which is mostly used for large internet using organization and NOC, ISP and Internet exchange

                A cache server is a dedicated network server or service acting as a server that saves Web pages or other Internet content locally. By placing previously requested information in temporary storage, or cache, a cache server both speeds up access to data and reduces demand on an enterprise's bandwidth. Cache servers also allow users to access content offline, including rich media files or other documents. 

                 A cache server is sometimes called a "cache engine."A cache server is almost always also aproxy server, which is a server that "represents" users by intercepting their Internet requests and managing them for users. Typically, this is because enterprise resources are being protected by a firewall server. That server allows outgoing requests to go out but screens all incoming traffic. A proxy server helps match incoming messages with outgoing requests. In doing so, it is in a position to also cache the files that are received for later recall by any user. To the user, the proxy and cache servers are invisible; all Internet requests and returned responses appear to be coming from the addressed place on the Internet. (The proxy is not quite invisible; its IPaddress has to be specified as a configuration option to the browser or other protocol program.

Usage of OSS / BSS servers

OSS / BSS server basically used for telecommunications for network distribution

OSS/BSS, in telecommunications, stands foroperations support system/business support system. The two systems, operated together by telecommunications service providers, are used to support a range of telecommunication services

OSS- dealing with the telecom network itself, supporting processes such as maintaining network inventory, provisioning services, configuring network components, and managing faults. (More Hardware Oriented.)

BSS - dealing with customers, supporting processes such as taking orders, processing bills, and collecting payments. (More Software Oriented.)

Of course, BSS and OSS is more complex than that. Usually different companies have different ways of distinguishing what is OSS and what is BSS.

Different between ISP and internet exchange

ISP internet service providers everybody knows about them

Internet Exchange 

       Now a days there are two types of NOC, central NOC and sub NOC. Basically central NOC (internet control room) as called Internet Exchange. Because there have AAA server with OSS/BOSS server, caching servers and not only data's , caching solution , OTT streaming server international gateway as called peering and direct lines all these facilities are available here.

    For example if their customers has consume  highest Google service, then they can join direct Google service from their network gateway router. 

What is AAA server where it be used

         AAA server basically used for NOC, central NOC and internet exchange..

     An AAA server is a server program that handles user requests for access to computer resources and, for an enterprise, provides authentication, authorization, and accounting (AAA)services. The AAA server typically interacts with network access andgateway servers and with databases and directories containing user information. The current standard by which devices or applications communicate with an AAA server is theRemote Authentication Dial-In User Service (RADIUS).

How does live telecasting channels are works

Since begining cable TV operators has been done live telecasting by using their own cable and OFC (optical fiber cable).

they can clearly distribute upto 20 to 30 kilometers. when they shoot and convert live videot in to stream and send to optical transmeeter edncodey.

and it be reached control room again it could down convert by a optical receiver. next the video can be telecast along with some logo,and adds by using

play out softwares.

in this technique audio and video are trasmited. when the shooting spot have mutliple camara it's been recording, then each and every

camara source as came control room by using the same technique and using mixing usint and online edit we can get a sing source.

if the channel owner haven't own fibe cable then they can use BSNL leased line. in the leased line have two types MLLN (managed leased line) & Non MLLN 

MLLN - Used to send signal from one end to anther end,for example if the signale send chennai to salem by using MLLN then only one connection must using this

line. and must want to get separate BSNL modem by using this MLLN.

Non-MLLN - Used multipoint distribution, for examble if the singel send from channai to salem meanwhile on the way we can telecast by reproduce to make drop at viluppuram and aathoor

that means we can create multiple IP's. single telecasting singnal using multiple distribution.

Another way of live telecasting we can do wireless technology. there also have some techniques. Live bag technology get's camara source and able to telecasting by streaming type.

but it must want high speed internet. if without internet we can do live steam by using OB (outdoor broadcasting) used for OB-van it been with big dish.

it have two types encrypted and non encrypted.

thanthi tv, cnn  are using encrypted.when the camera shoot source had send satellite by using OB-van and it down convert from channel broadcast control room

by using IRD. it also like a normal pay channel technique.

there are the techniques used for live telecasting