John, I suspect I may be jumping into the middle of a conversation without all the information, but wanted to lend my bit into this. Please forgive me if I've misunderstood something.
The goal is to send/receive high-quality video over the Internet to enable such things as lip-reading. The problems: #1 most ISPs only offer 256k upload bandwidth, creating transmission issues. some offer higher priced accounts that guarantee higher rates, but perhaps at prohibitive costs #2 ISPs that either ignore, remark, or do not honor DSCP (differential Services code Point) markings. #3 perhaps less than optimal codex for video - theoretically, a more efficient codec could be written packing more real video information into fewer packets or bytes, perhaps I'm incorrect here. The parts I know a litte about are #1 and #2 #1 bandwidth limit at the user's connection If you are limited to 256k upload bandwidth, and the video you are sending is 256k, there might be issues. The fix is to configure the sending PC to reserve ALL 256k for the video (based on the source or destination IP addresses, UDP/TCP ports). If this is done properly, the video would consume all 256k, anything else would have to wait until the video transmission was not sending. #2 Quality of service across the rest of the Internet. If the sending PC marks video traffic in accordance with networking "best practise" for loss and delay sensitive data - like voice and video, that's great. this marks each frame with a number that tells routers along the way to give these frames higher priority than say, an HTTP or FTP frame. Problem is - unless your ISP looks at, and honors these markings - it's useless. I think there are ISPs who offer the promise of looking and honoring your markings, but these are usually expensive commercial contracts for more than one DSL line. The other larger issue is - that even if the sender's ISP honors the markings, - no guarantee that the rest of the internet does. the frames might zip through the sender's ISP network, only to be delayed, or dropped somewhere else along the line. I'm sure there are ISPs who give bandwidth guarantees too, but at it's price. Thoughts: #1 perhaps some ISPs might be willing to offer something like a "hearing impaired DSL account" if they know the size of the community, and the potential revenue when they are the 1st and only ISP to provide end-to-end QOS (quality of service) for such services. #2 With Linux, you can always try to mark the frames with DSCP, reserve the ethernet card bandwidth to ensure video gets 100% of the 256k, and see if it works better. This would be done outside Ekiga with such tools as dsmark and tc http://lartc.org/ http://www.rns-nis.co.yu/~mps/linux-tc.html http://opalsoft.net/qos/VoIP.htm If this sounds at all interesting, I can work up a script for linux, but not sure this is a full solution. Best regards, John Hawley wrote: > Thanks very much for your suggestion but minicom and similar text based > devices have now been supplanted with sms, and IM both of which are poor > substitutes for face to face talking. > > The irritating thing is that we have used skype video calling for this > purpose for 3 or 4 years (with varying degrees of success) but the trend > for ever increasing camera resolution is outstripping bandwidth > resulting very good quality pictures but at a transmission rate > inadequate for lip-reading purposes. Perhaps I should clarify that by > bandwidth, I mean upload bandwidth, whereas download bandwidth has > steadily increased over the last few years, (currently because its > copper wires into the house its 8Meg), upload bandwidth has remained at > 250k thus end to end video is at 250K! UK ISPs appear to have no > interest in increasing this number! > > What I'm trying to achieve is to force all/most of that available > bandwidth into video stream and Ekiga would at least seem to offer that > prospect. > > It also seems to me that such a configuration, if it could be achieved, > would soon have a dedicated fan base amongst the hearing impaired and > potentially could attract (although I'm sure you're wary of "sponsors") > some funding from the EU or Deaf charities. > > Thanks again John H > > > > > > > _______________________________________________ > ekiga-list mailing list > [email protected] > http://mail.gnome.org/mailman/listinfo/ekiga-list > _______________________________________________ ekiga-list mailing list [email protected] http://mail.gnome.org/mailman/listinfo/ekiga-list
