Manuale d’uso / di manutenzione del prodotto D11624 del fabbricante TANDBERG
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Video on Frame Relay Tandberg D11624 rev 01.
Tandberg Video on Frame Relay D11624 rev. 01 2 Table of Contents 1. Introduction ............................................................................................................................................... 3 2. Background on transmission of video over frame relay .
Tandberg Video on Frame Relay D11624 rev. 01 3 1. Introduction This document is designed as an 'eye-opener' to video over frame relay and the idea is to show a solution that works. The equipment described in this document is the VFX-250S, a framer unit from Science Dynamics Corporation.
Tandberg Video on Frame Relay D11624 rev. 01 4 2. Background on transmission of video over frame relay The successful transmission of digitised voice over public frame relay data services the past few years has drawn attention to the question of whether video services can be transmitted over the same link.
Tandberg Video on Frame Relay D11624 rev. 01 5 3. Technical issues There are two potential technical issues, which may affect the quality of packetised, digitised video. One is delay, or more properly jitter. Jitter is the variation in delay from one frame to the next.
Tandberg Video on Frame Relay D11624 rev. 01 6 Cell based systems cut packet into fixed sizes Dropped frames are potentially a more serious problem. The frame relay standard allows the network service provider to control congestion by simply disposing of any frames which exceed the users CIR.
Tandberg Video on Frame Relay D11624 rev. 01 7 2. The second method is to establish a traffic prioritisation scheme for any channels carrying video through a FRAD (Frame Relay Access Devices) on a defined DLCI. This ensures that video frames are first out.
Tandberg Video on Frame Relay D11624 rev. 01 8 framer both at the ACT-recommended setting of 256 bytes and at 1.500 bytes (which is in line with the recommendations of other framer users) without any difference in the overall performance. You can connect either the VFX-250S or the ABL VT2C directly to a DSU/CSU on a frame relay network.
Tandberg Video on Frame Relay D11624 rev. 01 9 6. Application Overview The diagram below shows the use of the VFX-250S in a video-conferencing over frame relay application.
Tandberg Video on Frame Relay D11624 rev. 01 10 7. Technical Specification of VFX-250S 7. 1 Network & User Interface Connector: Female 37-pin D type to user equipment (Video codec) Male 37-pin D type to network equipment (FRAD) Interface: RS449 (X.
Tandberg Video on Frame Relay D11624 rev. 01 11 • 4 configuration entries, each of which contains TX and RX DLCI settings, User Clock Speed, Packet Length, and AVB • LMI type control selection &am.
Tandberg Video on Frame Relay D11624 rev. 01 12 8. Approvals FCC Class A Digital Devices and Peripherals This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules.
Tandberg Video on Frame Relay D11624 rev. 01 13 10. Economics of Video over Frame Relay The economics of video over frame relay are similar to those driving the use of voice over frame relay. Voice over frame relay is fairly well accepted as being economical when used in international applications.
Tandberg Video on Frame Relay D11624 rev. 01 14 11. Appendix A: Cables and Pinouts 11. 1 Standard Console Cable The console port on the VFX-250S conforms to EIA-232/V.
Tandberg Video on Frame Relay D11624 rev. 01 15 11. 2 Standard EIA-449/RS449 Cables 11. 2 .1 Network Cable 11. 2 .2 User Cable A note about RTS signalling: Some manufacturers state that their network interface is RS449 (which uses RS422 signalling levels) but actually use RS423 signals for the control leads.
Tandberg Video on Frame Relay D11624 rev. 01 16 11. 3 Standard EIA-530/RS530 Cables 11. 3 .1 Network Cable 11. 3 .2 User Cable.
Tandberg Video on Frame Relay D11624 rev. 01 17 11. 4 Standard V.35 Cables 11. 4 .1 Network Cable 11. 4 .2 User Cable.
Tandberg Video on Frame Relay D11624 rev. 01 18 12. Appendix C: Glossary and abbreviations AVB - Automatic Variable Buffer. Buffering - This is a term used to describe a method where data is held in a queue to allow equalisation of speeds on either side.
Tandberg Video on Frame Relay D11624 rev. 01 19 - This is a Videoconferencing term, which is used to identify picture break-up. Digital video pictures are made up of 1000’s of pixels, each representing a colour on the image. In videoconferencing, pixels are grouped into blocks (the number of which is determined by the speed of the link).
Un punto importante, dopo l’acquisto del dispositivo (o anche prima di acquisto) è quello di leggere il manuale. Dobbiamo farlo per diversi motivi semplici:
Se non hai ancora comprato il TANDBERG D11624 è un buon momento per familiarizzare con i dati di base del prodotto. Prime consultare le pagine iniziali del manuale d’uso, che si trova al di sopra. Dovresti trovare lì i dati tecnici più importanti del TANDBERG D11624 - in questo modo è possibile verificare se l’apparecchio soddisfa le tue esigenze. Esplorando le pagine segenti del manuali d’uso TANDBERG D11624 imparerai tutte le caratteristiche del prodotto e le informazioni sul suo funzionamento. Le informazioni sul TANDBERG D11624 ti aiuteranno sicuramente a prendere una decisione relativa all’acquisto.
In una situazione in cui hai già il TANDBERG D11624, ma non hai ancora letto il manuale d’uso, dovresti farlo per le ragioni sopra descritte. Saprai quindi se hai correttamente usato le funzioni disponibili, e se hai commesso errori che possono ridurre la durata di vita del TANDBERG D11624.
Tuttavia, uno dei ruoli più importanti per l’utente svolti dal manuale d’uso è quello di aiutare a risolvere i problemi con il TANDBERG D11624. Quasi sempre, ci troverai Troubleshooting, cioè i guasti più frequenti e malfunzionamenti del dispositivo TANDBERG D11624 insieme con le istruzioni su come risolverli. Anche se non si riesci a risolvere il problema, il manuale d’uso ti mostrerà il percorso di ulteriori procedimenti – il contatto con il centro servizio clienti o il servizio più vicino.
