Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
ProvoCityPower wrote: Also who says Fax should ever be required on IP? My office has been I'm fairly new here and don't mean to be contentious. We all have different perspectives as to what VOIP should be. My goal is to replace analog lines, not supplement them. I'm talking residential I am sure we all consider fax to be obsolete sometime soon. Meaning: when this generation of businessmen die out ;-) Supporting faxing over analogue lines to endpoints (clients) is important. However, transmission of these audio streams over Internet or large private IP networks, seems foolish. In most cases, there will be no guaranteed QoS, meaning that faxing will or will not work from time to time. It would be better use of the network to look into another architecture, where we decode the audio stream close to the fax device, transmit it as a tiff file with attached routing, T.38 or something else (maybe SIMPLE) and if the receiving end is another fax, encode it again into an fax audio stream. TPC.int (http://www.tpc.int) is running a fax service we could look into. OpenH323 seems to have work going on on T.38. We have work going on in regards to decoding and encoding fax streams. We should be able to solve this. I haven't looked into ENUM support for faxing, but it would be great if one could indicate how an endpoint receives faxes, by email to a printer, by a fax audio stream or something else (a courier delivering papers overnight with a fresh pizza attached ;-). What we need is people who sees this as a big enough problem to roll up their sleaves and work on it or open their wallets and pay someone to do it for the community. /O ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
On Sun, 2003-12-14 at 19:04, John Breeden wrote: How is Vonage doing it? http://www.vonage.com/features_fax.php unreliable, bandwidth hogging, inefficient ulaw. The point here is, if we are to make something, why make the same old crap when we can utilize our knowledge of the network to not bring old technology to the new. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Steve Underwood Sent: Sunday, December 14, 2003 2:24 PM To: [EMAIL PROTECTED] Subject: Re: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) ProvoCityPower wrote: The question asked here, why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. may speak volumes about the future role of VOIP. My plans are to role out a VOIP connection to thousands of Customers. Many have legacy fax equipment. Am I to assume that they will toss out their fax equipment and join the PC based faxing crowd? I don't think I can control this. If I am going to offer an aternative to the legacy wire providers then I have to offer a comparable service. One that for example allows a customer to use a legacy fax machine in the same way. If this thought sidetracks the intent of this thread, you have my apologies, but I do think that legacy fax functionality is essential. Legacy FAX will be very important for years. The last people to abandon it are the most senior managers. Therefore, apart from anything else, their buyin to a change to VoIP depends on keeping their olde worlde FAX facilities alive. However, I think this has nothing to do with the original poster's intent. Sending FAXes over IP as audio is dumb. Its troublesome, error prone, and consumes too much bandwidth. The right way is to use a FAX modem to translate between audio and the digital data stream of the image itself. Then the compact image data can be conveyed reliably. If the far end is not using IP, another modem can be used to return the FAX to its analogue form for delivery. If you wish to interwork traditional analogue FAX machines, with newer IP capable FAX machines you *have* to do this. This is what the H323 protocols do. T.38 is the relevant FAX over IP protocol. I don't know if there is a similar SIP standard, but there should be. FAX to e-mail and e-mail to FAX is the other inportant way to blend the old with the new. Regards, Steve ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users -- Steven Critchfield [EMAIL PROTECTED] ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, - Original Message - From: Steven Critchfield [EMAIL PROTECTED] On Sun, 2003-12-14 at 19:04, John Breeden wrote: How is Vonage doing it? http://www.vonage.com/features_fax.php unreliable, bandwidth hogging, inefficient ulaw. The point here is, if we are to make something, why make the same old crap when we can utilize our knowledge of the network to not bring old technology to the new. I totally agree with this... G.711 for inter Asterisk connections over WAN is totally inefficient (even if it can work sometimes). For LAN is acceptable and the standard FAX machine works great on ATA186, but far better on TDM400. X100 seems to deal better now with fax data too. Just sending the picture in some compressed format (JPG, GIF, etc.) between servers (one for each Fax page) and then converting back for a standard Fax device is the best option. Best regards, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
FAX over VoIP works fine, but it is bandwidth-hungry. I have no problems here picking up a FAX off the PSTN and routing it via VoIP to my SPA2000, and out the second port to a box running hylafax (no different than an analog FAX machine). As long as you use a high bitrate codec and can afford to lose approx 80K/s it's a non-issue. Mr. Critchfield is also onto something when he sugguests just keeping an analog line around for the fax: most (if not all) cities here in the states _REQUIRE_ that you keep X number of analog lines around (it's usually a function of how many employees you have) for emergency purposes (IE: power's out, building on fire, you need to call 911). Just plug the fax into one of those lines that you have to pay to keep anyway. -Pat -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Steven Critchfield Sent: Sunday, December 14, 2003 4:43 PM To: [EMAIL PROTECTED] Subject: RE: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) On Sun, 2003-12-14 at 12:18, [EMAIL PROTECTED] wrote: From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of ProvoCityPower The question asked here, why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. may speak volumes about the future role of VOIP. My plans are to role out a VOIP connection to thousands of Customers. Many have legacy fax equipment. Am I to assume that they will toss out their fax equipment and join the PC based faxing crowd? I don't think I can control this. If I am going to offer an aternative to the legacy wire providers then I have to offer a comparable service. One that for example allows a customer to use a legacy fax machine in the same way. I think what you're talking about here is an absolute necessity if VOIP is ever to compete for traditional analog service. A lot of users will not want to change their ways. As stupid as I think FAXing and FAX machines are there are still millions of people who prefer to send and recive a skewed low resolution fax on thermal paper than the transmit and receive them over a computer. Even though, I think FAXing is as ancient as sending a letter through the mail it needs to be supported however the end user wishes to use it. With that being said, I think it simply comes down to the codecs being used. I seem to recall that alaw and ulaw were acceptable codecs, though I know nothing about this first hand. The other option is some sort of FAX proxy, though that seems a little too complicated if you ask me. Did DVD players have to accommodate VHS tapes? Did VHS players have to accept beta? Why does VoIP have to deal with an accent protocol that can't handle lossy audio, nor irregular delays? Also why should we be soo wasteful when fax machines need a 80K codec to get the data across IP, and the faster machines I see say 15 secs per page. So why should we send 1.2meg when 150k is fine? Also who says Fax should ever be required on IP? My office has been using VoIP for all voice traffic for over a year now, but always left the fax machine on a analog line. The analog line was cheap enough to not be a concern. -- Steven Critchfield [EMAIL PROTECTED] ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
snip I totally agree with this... G.711 for inter Asterisk connections over WAN is totally inefficient (even if it can work sometimes). For LAN is acceptable and the standard FAX machine works great on ATA186, but far better on TDM400. Dan, you say fax works better on the TDM400 than the ATA186. I'm having problems with faxing on the TDM400. I had to drop the rx and tx rates on the fax machine down to 4800 baud to get it to work. I have ordered an ATA186 to see if I get better results. What rx and tx rates are you able to get to work through these devices? This may be slightly off topic, but I had to ask Dan about this specific case, my appologies. Walker -- DataCrest, Inc. -- Technically Superior ** Walker Haddock http://www.datacrest.com DataCrest, Inc.e-mail: [EMAIL PROTECTED] 1634A Montgomery Hwy.phone: 1-888-941-3282, 1-205-335-8589 Birmingham, AL 35216 fax: 1-205-823-7838 *** ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, - Original Message - From: Walker Haddock [EMAIL PROTECTED] Dan, you say fax works better on the TDM400 than the ATA186. I'm having problems with faxing on the TDM400. I had to drop the rx and tx rates on the fax machine down to 4800 baud to get it to work. I have ordered an ATA186 to see if I get better results. I have tried with several fax devices and have no problem with TDM400 /X100P. What rx and tx rates are you able to get to work through these devices? The default 9600 one. It can be a problem of X100 tuning for your provider line. If it does not work on TDM400, then for sure it will not work on ATA, in my opinion. This may be slightly off topic, but I had to ask Dan about this specific case, my appologies. No problem. Best regards, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
On Mon, Dec 15, 2003 at 05:06:57PM +0200, Dan wrote: Hi, - Original Message - From: Walker Haddock [EMAIL PROTECTED] Dan, you say fax works better on the TDM400 than the ATA186. I'm having problems with faxing on the TDM400. I had to drop the rx and tx rates on the fax machine down to 4800 baud to get it to work. I have ordered an ATA186 to see if I get better results. I have tried with several fax devices and have no problem with TDM400 /X100P. What rx and tx rates are you able to get to work through these devices? The default 9600 one. I tried 9600, most of the time the fax would auto negotiate this but it would get too many bad lines and cancel. It can be a problem of X100 tuning for your provider line. I'm usint a T1 PRI through a T100P for the other channel in the connection. I have disabled all echo cancel. I don't see how it can be caused by anything but hte TDM400. I'll go ahead and test with the ATA and see if I get better results. If it does not work on TDM400, then for sure it will not work on ATA, in my opinion. -- DataCrest, Inc. -- Technically Superior ** Walker Haddock http://www.datacrest.com DataCrest, Inc.e-mail: [EMAIL PROTECTED] 1634A Montgomery Hwy.phone: 1-888-941-3282, 1-205-335-8589 Birmingham, AL 35216 fax: 1-205-823-7838 *** ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Walker Haddock wrote: On Mon, Dec 15, 2003 at 05:06:57PM +0200, Dan wrote: Hi, - Original Message - From: Walker Haddock [EMAIL PROTECTED] Dan, you say fax works better on the TDM400 than the ATA186. I'm having problems with faxing on the TDM400. I had to drop the rx and tx rates on the fax machine down to 4800 baud to get it to work. I have ordered an ATA186 to see if I get better results. I have tried with several fax devices and have no problem with TDM400 /X100P. What rx and tx rates are you able to get to work through these devices? The default 9600 one. I tried 9600, most of the time the fax would auto negotiate this but it would get too many bad lines and cancel. It can be a problem of X100 tuning for your provider line. I'm usint a T1 PRI through a T100P for the other channel in the connection. I have disabled all echo cancel. I don't see how it can be caused by anything but hte TDM400. I'll go ahead and test with the ATA and see if I get better results. If it does not work on TDM400, then for sure it will not work on ATA, in my opinion. Its probably frame slips. Check the clock source for your T1, and make sure you are syncing to the PSTN. Regards, Steve ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
- Original Message - From: "Alastair Maw" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, December 12, 2003 4:58 PM Subject: Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-) On 12/12/03 13:56, Dan wrote: This is because the fax is transmitted using the audio stream. It is not related to the signaling protocol (SIP/IAX etc.) but to the audio codec used. Fax uses FSK modulation to transmit the data. If you compress this in a lossy way (GSM, MP3, whatever) then the integrity of the data is affected (more or less seriously depending on the codec used). Fax machines are generally quite picky, so compressing faxes is unlikely to work. I'm wondering why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. Who wants that??? By fax data I mean the data contained in a fax (basically a picture file), not the fax data audio stream. It can be converted (GIF or JPG) then sent reliable over a slow IP link. Just a special codec at both ends, able to pass the data to the fax app or a fax machine connected to a TDM400/ AT or whatever. It would be much less bandwidth intensive to decode the fax and send it over as proper data rather than audio, compressed using gzip/gif/png/something else. This is exactly what would be great to have it. The question asked here, "why on earth you want to push fax data over a VoIP link atall. Fax compression isn't very efficient." may speak volumes about the future role of VOIP. My plans are to role out a VOIP connection to thousands of Customers. Many have legacy fax equipment. Am I to assume that they will toss out their fax equipment and join the PC based faxing crowd? I don't think I can control this. If I am going to offer an aternative to the legacy wire providers then I have to offer a comparable service. One that for example allows a customer to use a legacy fax machine in the same way. If this thought sidetracks the intent of this thread, you have my apologies, but I do think that legacy fax functionality is essential. Jeff
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of ProvoCityPower Sent: Sunday, December 14, 2003 12:51 PM To: [EMAIL PROTECTED] Subject: Re: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) The question asked here, why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. may speak volumes about the future role of VOIP. My plans are to role out a VOIP connection to thousands of Customers. Many have legacy fax equipment. Am I to assume that they will toss out their fax equipment and join the PC based faxing crowd? I don't think I can control this. If I am going to offer an aternative to the legacy wire providers then I have to offer a comparable service. One that for example allows a customer to use a legacy fax machine in the same way. If this thought sidetracks the intent of this thread, you have my apologies, but I do think that legacy fax functionality is essential. Jeff I think what you're talking about here is an absolute necessity if VOIP is ever to compete for traditional analog service. A lot of users will not want to change their ways. As stupid as I think FAXing and FAX machines are there are still millions of people who prefer to send and recive a skewed low resolution fax on thermal paper than the transmit and receive them over a computer. Even though, I think FAXing is as ancient as sending a letter through the mail it needs to be supported however the end user wishes to use it. With that being said, I think it simply comes down to the codecs being used. I seem to recall that alaw and ulaw were acceptable codecs, though I know nothing about this first hand. The other option is some sort of FAX proxy, though that seems a little too complicated if you ask me. -Bill ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
On Sun, 2003-12-14 at 12:18, [EMAIL PROTECTED] wrote: From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of ProvoCityPower The question asked here, why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. may speak volumes about the future role of VOIP. My plans are to role out a VOIP connection to thousands of Customers. Many have legacy fax equipment. Am I to assume that they will toss out their fax equipment and join the PC based faxing crowd? I don't think I can control this. If I am going to offer an aternative to the legacy wire providers then I have to offer a comparable service. One that for example allows a customer to use a legacy fax machine in the same way. I think what you're talking about here is an absolute necessity if VOIP is ever to compete for traditional analog service. A lot of users will not want to change their ways. As stupid as I think FAXing and FAX machines are there are still millions of people who prefer to send and recive a skewed low resolution fax on thermal paper than the transmit and receive them over a computer. Even though, I think FAXing is as ancient as sending a letter through the mail it needs to be supported however the end user wishes to use it. With that being said, I think it simply comes down to the codecs being used. I seem to recall that alaw and ulaw were acceptable codecs, though I know nothing about this first hand. The other option is some sort of FAX proxy, though that seems a little too complicated if you ask me. Did DVD players have to accommodate VHS tapes? Did VHS players have to accept beta? Why does VoIP have to deal with an accent protocol that can't handle lossy audio, nor irregular delays? Also why should we be soo wasteful when fax machines need a 80K codec to get the data across IP, and the faster machines I see say 15 secs per page. So why should we send 1.2meg when 150k is fine? Also who says Fax should ever be required on IP? My office has been using VoIP for all voice traffic for over a year now, but always left the fax machine on a analog line. The analog line was cheap enough to not be a concern. -- Steven Critchfield [EMAIL PROTECTED] ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
ProvoCityPower wrote: The question asked here, why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. may speak volumes about the future role of VOIP. My plans are to role out a VOIP connection to thousands of Customers. Many have legacy fax equipment. Am I to assume that they will toss out their fax equipment and join the PC based faxing crowd? I don't think I can control this. If I am going to offer an aternative to the legacy wire providers then I have to offer a comparable service. One that for example allows a customer to use a legacy fax machine in the same way. If this thought sidetracks the intent of this thread, you have my apologies, but I do think that legacy fax functionality is essential. Legacy FAX will be very important for years. The last people to abandon it are the most senior managers. Therefore, apart from anything else, their buyin to a change to VoIP depends on keeping their olde worlde FAX facilities alive. However, I think this has nothing to do with the original poster's intent. Sending FAXes over IP as audio is dumb. Its troublesome, error prone, and consumes too much bandwidth. The right way is to use a FAX modem to translate between audio and the digital data stream of the image itself. Then the compact image data can be conveyed reliably. If the far end is not using IP, another modem can be used to return the FAX to its analogue form for delivery. If you wish to interwork traditional analogue FAX machines, with newer IP capable FAX machines you *have* to do this. This is what the H323 protocols do. T.38 is the relevant FAX over IP protocol. I don't know if there is a similar SIP standard, but there should be. FAX to e-mail and e-mail to FAX is the other inportant way to blend the old with the new. Regards, Steve ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
How is Vonage doing it? http://www.vonage.com/features_fax.php John Breeden Hawaii -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Steve Underwood Sent: Sunday, December 14, 2003 2:24 PM To: [EMAIL PROTECTED] Subject: Re: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) ProvoCityPower wrote: The question asked here, why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. may speak volumes about the future role of VOIP. My plans are to role out a VOIP connection to thousands of Customers. Many have legacy fax equipment. Am I to assume that they will toss out their fax equipment and join the PC based faxing crowd? I don't think I can control this. If I am going to offer an aternative to the legacy wire providers then I have to offer a comparable service. One that for example allows a customer to use a legacy fax machine in the same way. If this thought sidetracks the intent of this thread, you have my apologies, but I do think that legacy fax functionality is essential. Legacy FAX will be very important for years. The last people to abandon it are the most senior managers. Therefore, apart from anything else, their buyin to a change to VoIP depends on keeping their olde worlde FAX facilities alive. However, I think this has nothing to do with the original poster's intent. Sending FAXes over IP as audio is dumb. Its troublesome, error prone, and consumes too much bandwidth. The right way is to use a FAX modem to translate between audio and the digital data stream of the image itself. Then the compact image data can be conveyed reliably. If the far end is not using IP, another modem can be used to return the FAX to its analogue form for delivery. If you wish to interwork traditional analogue FAX machines, with newer IP capable FAX machines you *have* to do this. This is what the H323 protocols do. T.38 is the relevant FAX over IP protocol. I don't know if there is a similar SIP standard, but there should be. FAX to e-mail and e-mail to FAX is the other inportant way to blend the old with the new. Regards, Steve ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Did DVD players have to accommodate VHS tapes? Did VHS players have toaccept beta? Why does VoIP have to deal with an accent protocol that can't handlelossy audio, nor irregular delays?Also why should we be soo wasteful when fax machines need a 80K codec toget the data across IP, and the faster machines I see say 15 secs perpage. So why should we send 1.2meg when 150k is fine? Also who says Fax should ever be required on IP? My office has beenusing VoIP for all voice traffic for over a year now, but always leftthe fax machine on a analog line. The analog line was cheap enough tonot be a concern. -- Steven Critchfield [EMAIL PROTECTED] I'm fairly new here and don't mean to be contentious. We all have different perspectives as to what VOIP should be. My goal is to replace analog lines, not supplement them. I'm talking residential installations. I don't think I can ask these folks to leave their fax on an anolog line? I think that if we start deciding things for the Customer, then VOIP will be seen as an elitist toy for digitally inclined, instead of an acceptable alternative for the masses. No offense to the anti-fax coalition. Jeff
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi Jeff, I live in Provo and I think I understand the application you're referring to. Some folks in my neighborhood have been getting to be the beta testers for these cool new fiber links that the city is supposed to be laying out. If I only lived a few blocks over, I would be able to get one too. Darn. Anyway, I've been following this thread, and I'm wondering if an alternative might be to provide some sort of fax jack on the hardware you provide the customer that your network could notice and then treat differently from regular voice data? An even better alternative would be if asterisk could recognize a fax machine on the end of the line and use a different protocol or codec that would work with faxes. It sounds like some of the contributors to this thread were saying this is possible. But I'm not sure--I'm pretty new to asterisk and VoIP in general, so I could be wrong. Carl ProvoCityPower wrote: Did DVD players have to accommodate VHS tapes? Did VHS players have to accept beta? Why does VoIP have to deal with an accent protocol that can't handle lossy audio, nor irregular delays? Also why should we be soo wasteful when fax machines need a 80K codec to get the data across IP, and the faster machines I see say 15 secs per page. So why should we send 1.2meg when 150k is fine? Also who says Fax should ever be required on IP? My office has been using VoIP for all voice traffic for over a year now, but always left the fax machine on a analog line. The analog line was cheap enough to not be a concern. -- Steven Critchfield [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] I'm fairly new here and don't mean to be contentious. We all have different perspectives as to what VOIP should be. My goal is to replace analog lines, not supplement them. I'm talking residential installations. I don't think I can ask these folks to leave their fax on an anolog line? I think that if we start deciding things for the Customer, then VOIP will be seen as an elitist toy for digitally inclined, instead of an acceptable alternative for the masses. No offense to the anti-fax coalition. Jeff ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
It's just my lowly opinion but I too must agree when it comes to the consumer/soho (1 to 3 line) markets. CAUTION!!, DANGER!! Marketing Hat On!! Vonage, the most "visible" marketer of a voip consumer product must also agree. Vontage offers anip "fax line". usingcisco's ata. Vontagemust see some good reason for doing so. (I assume it's h.323). AT, MCI and Time Warner will be competing directly against Vonage when they introducetheir consumer voip products. I'd bet they too will be offering an ip fax line. Odds are you willbe competing against them too. If I was vonage I'd be telling the world how important a ip fax line was :-) Second, the residential/soho market almost demands replacement ofanalog with voip. It's almost impossible to justify the roi unless you do. Marketing Hat Off John Breeden Hawaii I'm fairly new here and don't mean to be contentious. We all have different perspectives as to what VOIP should be. My goal is to replace analog lines, not supplement them. I'm talking residential installations. I don't think I can ask these folks to leave their fax on an anolog line? I think that if we start deciding things for the Customer, then VOIP will be seen as an elitist toy for digitally inclined, instead of an acceptable alternative for the masses. No offense to the anti-fax coalition. Jeff
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
It's just my lowly opinion but I too must agree when it comes to the consumer/soho (1 to 3 line) markets. CAUTION!!, DANGER!! Marketing Hat On!! Vonage, the most visible marketer of a voip consumer product must also agree. Vontage offers an ip fax line. using cisco's ata. Vontage must see some good reason for doing so. (I assume it's h.323). AT, MCI and Time Warner will be competing directly against Vonage when they introduce their consumer voip products. I'd bet they too will be offering an ip fax line. Odds are you will be competing against them too. If I was vonage I'd be telling the world how important a ip fax line was :-) Personally, I dont think that the world in general really cares about an ip fax line. All they want is a system that works all the time/every time and doesn't require elaborate and convoluted setup. They're not ooohing and ahhhing about oooh, this uses VoIP. They just know that they can stop spending $30/mo on an analog phone line and they get their long distance either flat rate or for an absurdly low per minute rate. Don't sell it as VoIP. Sell it as a total replacement for the analog line. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of James Sharp Sent: Sunday, December 14, 2003 6:01 PM To: [EMAIL PROTECTED] Subject: RE: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) It's just my lowly opinion but I too must agree when it comes to the consumer/soho (1 to 3 line) markets. CAUTION!!, DANGER!! Marketing Hat On!! Vonage, the most visible marketer of a voip consumer product must also agree. Vontage offers an ip fax line. using cisco's ata. Vontage must see some good reason for doing so. (I assume it's h.323). AT, MCI and Time Warner will be competing directly against Vonage when they introduce their consumer voip products. I'd bet they too will be offering an ip fax line. Odds are you will be competing against them too. If I was vonage I'd be telling the world how important a ip fax line was :-) Personally, I dont think that the world in general really cares about an ip fax line. All they want is a system that works all the time/every time and doesn't require elaborate and convoluted setup. They're not ooohing and ahhhing about oooh, this uses VoIP. They just know that they can stop spending $30/mo on an analog phone line and they get their long distance either flat rate or for an absurdly low per minute rate. Don't sell it as VoIP. Sell it as a total replacement for the analog line. broadband phone ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi Steve, - Original Message - ?From: Steve Underwood [EMAIL PROTECTED] ... . However, I think this has nothing to do with the original poster's intent. You're right. Let's go back to my original problem. There is any chance to make RxFax work with any type of fax machine? It works for me just with a single (hardware) one. The TxFax works with all of them. ..then... we can think further, to support fax data (not fax audio) over slow links..:-) Thank you and best regards, Dan P.S. I think that RxFax and TxFax applications, together with the fax suport in * (tone detection and routing) has a huge potential... keep up the good work. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
On Fri, 2003-12-12 at 09:29, Dan wrote: Hi, - Original Message - From: Alastair Maw [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, December 12, 2003 4:58 PM Subject: Re: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) On 12/12/03 13:56, Dan wrote: This is because the fax is transmitted using the audio stream. It is not related to the signaling protocol (SIP/IAX etc.) but to the audio codec used. Fax uses FSK modulation to transmit the data. If you compress this in a lossy way (GSM, MP3, whatever) then the integrity of the data is affected (more or less seriously depending on the codec used). Fax machines are generally quite picky, so compressing faxes is unlikely to work. I'm wondering why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. Who wants that??? By fax data I mean the data contained in a fax (basically a picture file), not the fax data audio stream. It can be converted (GIF or JPG) then sent reliable over a slow IP link. Just a special codec at both ends, able to pass the data to the fax app or a fax machine connected to a TDM400/ AT or whatever. It would be much less bandwidth intensive to decode the fax and send it over as proper data rather than audio, compressed using gzip/gif/png/something else. This is exactly what would be great to have it. Sounds like you want app_rcfax at the pstn to decode the fax data, then it would somehow transfer the image file to your local machine via the slow link and use app_tcfax to send the image to your local fax machine. -- Steven Critchfield [EMAIL PROTECTED] ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
On Sat, 2003-12-13 at 05:14, Dan wrote: Hi, - Original Message - From: Steven Critchfield [EMAIL PROTECTED] Sounds like you want app_rcfax at the pstn to decode the fax data, then it would somehow transfer the image file to your local machine via the slow link and use app_tcfax to send the image to your local fax machine. Yup! This is what would be great to exist. I want to be able to reliable transfer faxes between Asterisk servers using slow links, but still keeping the standard fax functionality locally. While I haven't tested it much, my first use of app_rxfax and app_txfax worked fine. The glue is little more than procmail and sample.call combined with working mail servers. I have faith that Steve's work will continue to make the functionality better and it will work more often with the variety of fax machines out there. -- Steven Critchfield [EMAIL PROTECTED] ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, From: Steven Critchfield [EMAIL PROTECTED] While I haven't tested it much, my first use of app_rxfax and app_txfax worked fine. The glue is little more than procmail and sample.call combined with working mail servers. I have faith that Steve's work will continue to make the functionality better and it will work more often with the variety of fax machines out there. I have done tests with several fax machines. txfax works great will all of them, including software, but rxfax works for me with just a single old Samsung fax machine. Anyway, it is a great application and the integration with asterisk is good enough for receiving faxes, but to send them is a little bit cumbersome Steve, if you read this, keep up the good work and thanks. Best regards, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Tilghman Lesher wrote: On Friday 12 December 2003 07:25, Dan wrote: Hi, It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. You're not going to get that working because GSM is a lossy codec. It is able to get extreme savings in size, because it optimizes out parts of the sound that most humans don't hear. However, that same bandwidth that humans don't hear is exactly the bandwidth that the fax application uses to transmit valuable portions of the image. Therefore, the GSM codec is never going to be appropriate for sending faxes. Besides, if you need low bitrates for your IP connection, you're likely to experience delays in the fax negotiation -- which will probably result in a failed fax attempt. If you want to be able to send faxes in this way, then negotiate the fax at one end, and email the resulting TIFF to the other end. Added to FAQ and http://www.voip-info.org/tiki-index.php?page=Asterisk+fax Thank you both! /O ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
[Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. Just a thought, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Dan wrote: Hi, It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. Just a thought, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users My understanding is that fax calls are ONLY possible with G711/SIP not IAX. Anyone? Ta SJ ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, - Original Message - From: Senad Jordanovic [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, December 12, 2003 3:42 PM Subject: RE: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) Dan wrote: Hi, It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. Just a thought, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users My understanding is that fax calls are ONLY possible with G711/SIP not IAX. Anyone? This is because the fax is transmitted using the audio stream. It is not related to the signaling protocol (SIP/IAX etc.) but to the audio codec used. ..but if we can pack the fax data in a different type of stream then maybe... we can use GSM too... I talk about IAX, because this is the main one used by Asterisk. G.711 cannot be used for slow links, but this does not mean that the fax data (a couple of KB) cannot be passed reliable between 2 * servers using low bandwidth codecs or, why not, even another protocol... BR, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, faxing works great with IAX/IAX2. Even over a 100ms ADSL link. It does not really depend on the protocol, only on the codec. regards kapejod Am Fr, 2003-12-12 um 14.42 schrieb Senad Jordanovic: Dan wrote: Hi, It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. Just a thought, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users My understanding is that fax calls are ONLY possible with G711/SIP not IAX. Anyone? Ta SJ ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
- Original Message - From: Klaus-Peter Junghanns [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, December 12, 2003 9:02 AM Subject: RE: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) Hi, faxing works great with IAX/IAX2. Even over a 100ms ADSL link. It does not really depend on the protocol, only on the codec. regards kapejod Can you give us some detail about your config to do this? Either Dan's not tried it (maybe he didn't think it would work), or couldn't make it work. - Andrew Thompson http://aktzero.com/ Your eyes are weary from staring at the CRT. You feel sleepy. Notice how restful it is to watch the cursor blink. Close your eyes. The opinions stated above are yours. You cannot imagine why you ever felt otherwise. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Dan wrote: Hi, - Original Message - From: Senad Jordanovic [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, December 12, 2003 3:42 PM Subject: RE: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) Dan wrote: Hi, It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. Just a thought, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users My understanding is that fax calls are ONLY possible with G711/SIP not IAX. Anyone? This is because the fax is transmitted using the audio stream. It is not related to the signaling protocol (SIP/IAX etc.) but to the audio codec used. ..but if we can pack the fax data in a different type of stream then maybe... we can use GSM too... I talk about IAX, because this is the main one used by Asterisk. G.711 cannot be used for slow links, but this does not mean that the fax data (a couple of KB) cannot be passed reliable between 2 * servers using low bandwidth codecs or, why not, even another protocol... BR, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users Great. :) In that case This issue is sorted and very cool! ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
[Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. I suppose that with SteveU's fax receive stuff, it should be possible to convert the fax to an image, and then send the images along in IAX image frame types.. I.e. AST_FRAME_IMAGE/AST_FORMAT_PNG. You'd need to figure out how to get the call to filter through the fax stuff, such that the multiple audio frames on one side ended up as a set of Image frames on the other.. -SteveK ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
- Original Message - From: Dan [EMAIL PROTECTED] To: Asterisk Users [EMAIL PROTECTED] Sent: Friday, December 12, 2003 8:25 AM Subject: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. Sounds like you are thinking of something like T.38. T.38 is a FAX over IP protocol but my guess is that there would be licensing issues using it with Asterisk. It probably would not be that hard for someone to come up with a completely open FAX over IP protocol. A FAX over IP protocol would not have to operate in real time like VOIP. You could actually use acknowledge signals and retransmit packets that are dropped so that you get a perfect fax transmission. This can not be done with VOIP because by the time you realize you have missed a packet it is too late to re-transmit the packet. With FAX over IP it just means it takes a little longer to transmit the page. You could also design the protocol so that you could transmit at whatever rate you wanted. Slower links would use less bandwidth but take longer to send. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
On 12/12/03 13:56, Dan wrote: This is because the fax is transmitted using the audio stream. It is not related to the signaling protocol (SIP/IAX etc.) but to the audio codec used. Fax uses FSK modulation to transmit the data. If you compress this in a lossy way (GSM, MP3, whatever) then the integrity of the data is affected (more or less seriously depending on the codec used). Fax machines are generally quite picky, so compressing faxes is unlikely to work. I'm wondering why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. It would be much less bandwidth intensive to decode the fax and send it over as proper data rather than audio, compressed using gzip/gif/png/something else. Alastair ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, - Original Message - From: Jim Flagg [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, December 12, 2003 4:54 PM Subject: Re: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) - Original Message - From: Dan [EMAIL PROTECTED] To: Asterisk Users [EMAIL PROTECTED] Sent: Friday, December 12, 2003 8:25 AM Subject: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. Sounds like you are thinking of something like T.38. T.38 is a FAX over IP protocol but my guess is that there would be licensing issues using it with Asterisk. It probably would not be that hard for someone to come up with a completely open FAX over IP protocol. A FAX over IP protocol would not have to operate in real time like VOIP. You could actually use acknowledge signals and retransmit packets that are dropped so that you get a perfect fax transmission. This can not be done with VOIP because by the time you realize you have missed a packet it is too late to re-transmit the packet. With FAX over IP it just means it takes a little longer to transmit the page. You could also design the protocol so that you could transmit at whatever rate you wanted. Slower links would use less bandwidth but take longer to send. Exactly. Mark, how about a FIAX protocol?.. :-)) Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, - Original Message - From: Alastair Maw [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, December 12, 2003 4:58 PM Subject: Re: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) On 12/12/03 13:56, Dan wrote: This is because the fax is transmitted using the audio stream. It is not related to the signaling protocol (SIP/IAX etc.) but to the audio codec used. Fax uses FSK modulation to transmit the data. If you compress this in a lossy way (GSM, MP3, whatever) then the integrity of the data is affected (more or less seriously depending on the codec used). Fax machines are generally quite picky, so compressing faxes is unlikely to work. I'm wondering why on earth you want to push fax data over a VoIP link at all. Fax compression isn't very efficient. Who wants that??? By fax data I mean the data contained in a fax (basically a picture file), not the fax data audio stream. It can be converted (GIF or JPG) then sent reliable over a slow IP link. Just a special codec at both ends, able to pass the data to the fax app or a fax machine connected to a TDM400/ AT or whatever. It would be much less bandwidth intensive to decode the fax and send it over as proper data rather than audio, compressed using gzip/gif/png/something else. This is exactly what would be great to have it. BR, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, Citeren Steve Kann [EMAIL PROTECTED]: It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. This would mean implementing some basic store and forward routines, which would be great for fax relaying over slow/unreliable links. Ofcourse this can be taken out of asterisk and routed via e-mail for instance. A simple procmail rule on the receiving end could enable sending it off to the local faxmachine... -- Met vriendelijke groet, Florian Overkamp ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
wasim: yes i am! actually i always was ;-) ok, here is my setup Fax machine - ISDN pbx - (chan_capi) - Asterisk 1 - LAN(chan_iax2) - Asterisk 2 - Internet 100ms (chan_iax2) - Asterisk 3 - (chan_capi) - ISDN pbx - Fax machine i use plain iax2, no trunking. regards kapejod Am Fr, 2003-12-12 um 15.15 schrieb Andrew Thompson: - Original Message - From: Klaus-Peter Junghanns [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, December 12, 2003 9:02 AM Subject: RE: [Asterisk-Users] FAX, IAX and *Maybe I'm dreaming...:-) Hi, faxing works great with IAX/IAX2. Even over a 100ms ADSL link. It does not really depend on the protocol, only on the codec. regards kapejod Can you give us some detail about your config to do this? Either Dan's not tried it (maybe he didn't think it would work), or couldn't make it work. - Andrew Thompson http://aktzero.com/ Your eyes are weary from staring at the CRT. You feel sleepy. Notice how restful it is to watch the cursor blink. Close your eyes. The opinions stated above are yours. You cannot imagine why you ever felt otherwise. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Alastair Maw wrote: Fax uses FSK modulation to transmit the data. If you compress this in a lossy way (GSM, MP3, whatever) then the integrity of the data is affected (more or less seriously depending on the codec used). Fax machines are generally quite picky, so compressing faxes is unlikely to work. Its actually DPSK or QAM (depending on the bit rate), not FSK. FSK is used for the control information, but not for the image. Regards, Steve ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Florian Overkamp wrote: Hi, Citeren Steve Kann [EMAIL PROTECTED]: It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. This would mean implementing some basic store and forward routines, which would be great for fax relaying over slow/unreliable links. Ofcourse this can be taken out of asterisk and routed via e-mail for instance. A simple procmail rule on the receiving end could enable sending it off to the local faxmachine... Yes, I think that it can be done with two Hylafax boxes. At the far end one Hylafax box receive the fax, send the image file by e-mail to the local Hylafax box which in turn send the image file to the fax machine number indicated in the e-mail address body. The local Hylafax works with sendmail with a patch already done for Hylafax. Jorge ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
On Friday 12 December 2003 07:25, Dan wrote: Hi, It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. You're not going to get that working because GSM is a lossy codec. It is able to get extreme savings in size, because it optimizes out parts of the sound that most humans don't hear. However, that same bandwidth that humans don't hear is exactly the bandwidth that the fax application uses to transmit valuable portions of the image. Therefore, the GSM codec is never going to be appropriate for sending faxes. Besides, if you need low bitrates for your IP connection, you're likely to experience delays in the fax negotiation -- which will probably result in a failed fax attempt. If you want to be able to send faxes in this way, then negotiate the fax at one end, and email the resulting TIFF to the other end. -Tilghman ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
On Friday 12 December 2003 07:25, Dan wrote: Hi, It would be great if the IAX protocol will be able to tranfer fax data (even converted in another format) between Asterisk boxes, using low bandwidth codecs like GSM. I know that this is possible only with the G.711 now (passing faxes using the audio stream), but maybe in the future...some native support will permit this. Smells like asterisk needs a T.38 implementation Jeremy McNamara ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] FAX, IAX and *....Maybe I'm dreaming...:-)
Hi, - Original Message - From: Tilghman Lesher [EMAIL PROTECTED] On Friday 12 December 2003 07:25, Dan wrote: You're not going to get that working because GSM is a lossy codec. It is able to get extreme savings in size, because it optimizes out parts of the sound that most humans don't hear. However, that same bandwidth that humans don't hear is exactly the bandwidth that the fax application uses to transmit valuable portions of the image. I know this.. Therefore, the GSM codec is never going to be appropriate for sending faxes. Besides, if you need low bitrates for your IP connection, you're likely to experience delays in the fax negotiation -- which will probably result in a failed fax attempt. If you want to be able to send faxes in this way, then negotiate the fax at one end, and email the resulting TIFF to the other end. Or maybe a separate channel for FAX.. BR, Dan ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
