Real Time Streaming Essay

Nowadays many people explore the possibilities for consuming multimedia over IP networks using Internet TV, IPTV or Mobile TV solutions. The majority of solutions on the market use real-time streaming. Real-time streaming-real-time-content delivery (live events viewed as they happen) and the ability to play content as soon as transmission is started are two advantages. First, Media protocols often have difficulty getting around firewalls and routers because they are commonly based on UDP sockets over unusual port numbers. HTTP-based media delivery has no such problems because firewalls and routers know to pass HTTP downloads through port 80. Second, HTTP media delivery has the ability to use standard HTTP servers and standard HTTP caches (or

Chunks can be separated physically (a separate file for each chunk of content) or logically (all content chunks stored in a single file). For protocols that are based on physically separated chunks, progressive download starts with the client downloading a description file that contains an ordered list of uniform resource identifiers (URI) referring to media files (each containing a single chunk of content) that the client may consume. Protocols that are based on logically separated chunks rely on a file format that allows addressing parts of the content at a number of predefined access points (time offsets). For such protocols, at the start of the progressive download session, the client downloads a description file that contains the name of the media file and the rules to create a URI that points to a chunk with a given time offset. Physical separation can be used with HTTP Live Streaming and 3GPP adaptive HTTP Streaming, whereas Microsoft Smooth Streaming is a solution example that uses logical separation of chunks. Since each chunk has a unique address in progressive download, web caching can be utilized, which makes progressive download more scalable than