| 404-movie | When a stream can't be reached a 404 video will be served to the viewer. It is possible to change this movie see: Appendix F: Custom 404 errors for more information. |
| Account administrator | The Account administrator is the principal user of a VDO-X account: this is the only user that has the ability to make changes to data associated with the account |
| Account rights | An account can have the following features: Live streaming, HTTP remote directory and Recording. You can contact your reseller if you want a feature enabled. |
| Active request routing | Active request routing routes requests based on real time statistics of the CDN performance |
| Afterburner | Afterburner collects all logs from XL-Media Servers in the Jet-Stream CDN and processes these in order to calculate historical request statistics which may for instance be used for billing |
| Anti Rediraptor-bypass mechanism (ARB) | ARB is a mechanism built-in the Jet-Stream CDN that ensures that it is impossible to request content from an XL-Media Server without using the Rediraptor. |
| API | Application Programming Interface is a standard abbreviation used in software design to refer to a collection of predefined interactions available in your software that may be used by other software to access functionality in your own software. |
| Bursting server | Bursting servers are used to handle popular content. This can be an Overflow or an Edge server. |
| CDN (Content Delivery Network) | A CDN is an network that has functionality built-in ensuring the best possible delivery of content from its storage location to the location from which a request originates |
| CDN Modus | CDN Modus is the strategy used to configure the networks which will be connected with Edge locations |
| Chunk | Chunk is used by HTTP based streaming protocols. It is a video cut in chunks of a couple of seconds. |
| Chunking | Chunking is the process of making a stream chunked. |
| Core server | The Core server(s) is an XL-Media Server optimized for storage. Core servers handle requests for non-popular content |
| Distribute files | Distribute files is a feature in VDO-X to mark an asset as populair and send the asset to one or multiple Bursting servers and to redirect new viewers to the Bursting server(s) |
| Download files | Download files are files(assets) that can be downloaded by a webserver. A download file cannot be used by streaming protocols. |
| Edge server | Edge servers are essentially a geographically optimized Overflow server. An Edge server must be configured with a list of networks and when the number of requests for a certain item from those networks grows above the popularity threshold, that item will be moved to the Edge server. On top of that requests that do not originate from one of the connected networks will never be directed to the Edge server. |
| Embed Code Generator | The Embed Code Generator is a wizard that produces code to embed given content in your website and the Rediraptor-URL required to request it |
| File Lock | File lock is a feature to lock : files, live streams, and HTTP Remote Directories, meaning that playout is only possible when the correct token is passed to the Rediraptor |
| Framerate | Framerate is the number of video frames in a video, expressed as a number per second. Your eye has a processing power of about 10 to 12 fps, movie content should at least have about 20 fps in order to make it look 'smooth'. |
| Geo-group | A Geo-Group is sa set of countries, used for geo-locking |
| Geo-lock | Geo-locking can be used on assets an livestreams. This way only viewers from the specified Geo-Group can watch the video. |
| Historical statistics | Historical statistics are an exact calculation of bandwidth usage based on the logs of all XL- Media Servers in the CDN. The Afterburner component does all the work in collecting the logs and doing all the calculations. The historical statistics are split up between the used services. |
| HTTP streaming | HTTP-based streaming technologies HLS (Apple), HDS (Adobe), Smooth (Microsoft) and MPEG-DASH break up your movie into chunks, and then use the standard HTTP protocol to download each chunk and mending all chunks together while playing |
| Ingest | Ingest is the all pre-processing process that needs to be executed before new content can be made available for viewing |
| Intake server | an XL-Media Server specialized for ingesting live streams. Pull streams will pulled from these servers and push streams will need to publish to these servers. |
| Keyframe | Most streaming formats don't send full frames, but only differences between frames. This results in a massive compression of the required data transfer. The downside is that small errors in the transmission will build up in time. For that reason every few frames a full frame is transferred, resetting any accumulated errors. We advise to configure your encoder to send a keyframe every 2 seconds, i.e. every 2*FR frames, with FR the framerate. |
| Live stream | Live stream is streaming content that is generated in realtime and must be played in realtime as well to prevent parts of the contents not being displayed |
| Lock | lock is a feature to lock : files, live streams, and HTTP Remote Directories, meaning that playout is only possible when the correct token is passed to the Rediraptor |
| Management server | The Management server is the application server in the Jet-Stream CDN solution |
| Multi bit rate | Multi bit rate is a streaming asset that is composed of a number of versions of the same video at different bit rates. This allows players that support such files to switch between bit rates in reaction to the available bandwidth. |
| Overflow server | The Overflow server is an XL-Media Server optimized for traffic. As soon as content becomes popular, the Rediraptor will start to redirect new requests for it to (one of) these servers |
| Passive request routing | Passive request routing is Fixed, static load balancing, found with many different names, but essentially nothing more than a Round Robin DNS balancer of a predetermined pool of servers. |
| Popular content | An asset is considered popular content when the number of requests per minute for a given item grows above a pre-configured threshold (individually configurable for each account) new requests will be sent to Bursting servers instead of Core servers |
| Pseudo-streaming | Pseudo-streaming is playing a normal movie download while it is being downloaded. It looks as if the file is being streamed, because it starts playing very quickly, but you can't skip to a part that has not been downloaded |
| Pull stream | A live stream that is pulled from an origin location by the Intake server(s) |
| Push stream | A live stream that is actively pushed by the encoder to the Intake server(s) |
| Real time statistics | VDO-X is capable of displaying some basic (near) real time statistics, which are calculated from Rediraptor data |
| Rediraptor | The Rediraptor-URL is the active request router used to access content in the Jet-Stream CDN. Being an active router it is possible to respond in realtime to changes in the CDN, enabling realtime optimization of delivery |
| Rediraptor-URL | Rediraptor-URL is a general name used to refer to the full URL that should be sent to a Rediraptor in order to view content stored in the CDN. |
| Secure ID | The Secure ID a random string, unique to each account, which is required for calculating the Token that must be passed to the Rediraptor in order to access items with a Lock |
| Redundancy | Redundancy is making sure that each component in an integrated system has a backup |
| Single point of failure | Single point of failure is a component in an integrated system that causes the full system tofail if just that component fails |
| Streaming files | A Streaming file is a file that is physically present (VOD) and which will be played by a streaming service, i.e. a service that does not allow downloading the file, but instead sends frames |
| Token | A Token is a string of characters, calculated by hashing a long input string that amongst other things includes the Secure ID, and because the Secure ID is only known by the owner, the token can not be reproduced by anyone other than the owner. |
| True streaming | Examples of True streaming protocols are: MMS, RTMP (and variants) or RTSP. These protocols provide a more or less continuous stream of frames, in contrast with HTTP streaming or pseudo-streaming |
| Undistribute files | Undistribute files is a function in VDO-X. The function will remove a file from a Bursting server, and to send new viewers to Core servers |
| User rights | User rights are a list of rights assigned to an individual user which controls |
| VoD (Video on Demand) | VoD is a physical file that stores some movie content |
| XL-Media Server | The XL-Media Server is a media server in the Jet-Stream CDN, which may run any combination of software capable of playing out movie content. Their contents is controlled by the Management server, and they handle requests, but only if the original request was handled by a Rediraptor. |