Hi, A lot of people talk about grooming to make VoIP work smoothly, not just for FAX. However, most people can only achieve grooming in one direction. Their ISP will not cooperate, and groom what is sent to the subscriber. Unless you just keep your DSL link very lightly loaded, by doing no browsing, file transfer, or anything else which can send sudden burst of data to you, grooming doesn't do a whole lot of good.
Jonn R Taylor wrote: > This is caused by your DSL/cable modem buffering the data internally. To > resolve this you need to feed the modem at a data rate that prevents it from > buffering. I solved this by using a shaping bridge server that does nothing > but control the data in and out of the internet connection. I have steady > 21ms ping times to the server that my RTP traffic comes from. > > I do faxing over VOIP every day and it works! But it only works if you have a > stable internet connection with an SLA, which I have. Also having an ISP that > only uses a pure IP network makes a big difference. Some DSL providers use > ATM to transport IP and this causes high packet loss when their network is > busy. > > T.38 is a great idea but we need large scale implementation of it, with > standards for it to work. > > Here is my hylafax log from last week. I removed the numbers for privacy > reasons. > > Facsimile received since last week: > > Pages Time Pg/min Errs TypRate TypData > 1 3:17 0.3 0 14400 2-D MMR > 26 16:55 1.5 0 9600 1-D MH > 2 0:46 2.6 0 14400 2-D MMR > 13 5:13 2.5 0 14400 2-D MMR > 14 5:48 2.4 0 14400 2-D MMR > 5 2:33 2.0 0 14400 2-D MMR > 1 0:28 2.1 0 14400 2-D MMR > 1 0:31 1.9 0 14400 2-D MMR > ------------------------------------------------------------------------------------------ > Total 63 35:31 1.8 A lot of people who say faxing works actually achieve good results only through a lot of ECM retries. Your pages per minute figures, apart from the first one, look like they were probably for pretty clean transfers. It depends a lot on the ATA. ATAs which try to be more clever about voice quality tend to stop FAX working completely. Of course, they have some FAX related options in their menus, just to look more impressive. :-) If you have a set up that works, stick with it. Don't expect to be able to repeat the result elsewhere. Steve _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
