Re: [Asterisk-Users] GSM ISDN gateway to quadbri NT port under bristuffed Asterisk - where to set gain (I have unreliable inband dtmf recognition )?
Peter Svensson wrote: On Tue, 21 Jun 2005, Leandro Morgado wrote: Steve Underwood wrote: Robert Rozman wrote: I'm getting unreliable dtmf recognition (it works fine for 4-5 digits, errors (duplicates) on more), when transferred inband from gsm gateway to NT port of quadbri under bristuffed Asterisk. We get these quite often. If there is any line noise asterisk will interpret it as the end of a digit and then detect the same digit again. We are connected to the pstn via isdn. The problem is with calls where the dtmf tones are a bit unclean, i.e. too much energy is in the overtones. Clean dtmf tones seem to be much more resistant to line noise. Out other systems are more accepting of slightly off-spec dtmf tones. People often make claims like this, but never seem able to back them up. They usually turn out to be a wildy set receive gain, wrong codecs, or something equally screwed up. Can you quote chapter and verse for a real problem? The DTMF detector in * is one of the most robust around. Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] GSM ISDN gateway to quadbri NT port under bristuffed Asterisk - where to set gain (I have unreliable inband dtmf recognition )?
Leandro Morgado wrote: Steve Underwood wrote: Robert Rozman wrote: Hi, I'm getting unreliable dtmf recognition (it works fine for 4-5 digits, errors (duplicates) on more), when transferred inband from gsm gateway to NT port of quadbri under bristuffed Asterisk. Since Asterisk is claimed to have good dtmf recognizer, I suspect there are some settings to workarouned... I've tried dtmf relax, but didn't help, so I suspect gain settings Is there any other possible cause of unreliable dtmf inband recognition ? Where can I set gain on voice channel (I guess majority of settings under bristuff in zaptel.conf are dummy) ? Any other advice on this problem or similar experience ? Thanks in advance, I kind of amazed if works at all when getting DTMF out of a GSM phone. You really shouldn't expect it to. We have sucessfully read incoming DTMF from: a) Nokia32 Analog GSM connected to TDM400 (had to use relaxdtmf with chan_zap) b) Ateus BRI ISDN GSM connected to AVM Fritz (had to patch chan_capi 0.3.5 to support relaxdtmf) Question (I'm from a software eng. background, not telco): What would be the reason for not receiving DTMF from a GSM phone/gateway? Do you have the time to explain why? (I'm really interested in learning :) The low bit rates codecs used for GSM cannot carry DTMF without seriously corrupting it. To allow DTMF to be sent to things like IVRs the GSM protocol alows the handset to send a message to the basestation to tell it to send a DTMF digit to the wireline network. The timing of these digits is completely unrelated to the user pressing keys on the phone, so any input method based on DTMF timing does not work. There is usually no need for DTMF to be sent reliably from a basestation to a handset, so the GSM protocol makes no provision for it. DTMF might or might not get through. The signals are quite distorted, but they are still present. Its pretty hit and miss. GSM 06.10 (the original GSM codec, which things like Asterisk also support) tends to work quite a bit of the time. The newer codecs (EFR, half-rate and AMR) tend not to. Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] GSM ISDN gateway to quadbri NT port under bristuffed Asterisk - where to set gain (I have unreliable inband dtmf recognition )?
Steve Underwood wrote: Robert Rozman wrote: Hi, I'm getting unreliable dtmf recognition (it works fine for 4-5 digits, errors (duplicates) on more), when transferred inband from gsm gateway to NT port of quadbri under bristuffed Asterisk. Since Asterisk is claimed to have good dtmf recognizer, I suspect there are some settings to workarouned... I've tried dtmf relax, but didn't help, so I suspect gain settings Is there any other possible cause of unreliable dtmf inband recognition ? Where can I set gain on voice channel (I guess majority of settings under bristuff in zaptel.conf are dummy) ? Any other advice on this problem or similar experience ? Thanks in advance, I kind of amazed if works at all when getting DTMF out of a GSM phone. You really shouldn't expect it to. We have sucessfully read incoming DTMF from: a) Nokia32 Analog GSM connected to TDM400 (had to use relaxdtmf with chan_zap) b) Ateus BRI ISDN GSM connected to AVM Fritz (had to patch chan_capi 0.3.5 to support relaxdtmf) Question (I'm from a software eng. background, not telco): What would be the reason for not receiving DTMF from a GSM phone/gateway? Do you have the time to explain why? (I'm really interested in learning :) Thanks, Leandro ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] GSM ISDN gateway to quadbri NT port under bristuffed Asterisk - where to set gain (I have unreliable inband dtmf recognition )?
On Tue, 21 Jun 2005, Leandro Morgado wrote: Steve Underwood wrote: Robert Rozman wrote: I'm getting unreliable dtmf recognition (it works fine for 4-5 digits, errors (duplicates) on more), when transferred inband from gsm gateway to NT port of quadbri under bristuffed Asterisk. We get these quite often. If there is any line noise asterisk will interpret it as the end of a digit and then detect the same digit again. We are connected to the pstn via isdn. The problem is with calls where the dtmf tones are a bit unclean, i.e. too much energy is in the overtones. Clean dtmf tones seem to be much more resistant to line noise. Out other systems are more accepting of slightly off-spec dtmf tones. Peter ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
[Asterisk-Users] GSM ISDN gateway to quadbri NT port under bristuffed Asterisk - where to set gain (I have unreliable inband dtmf recognition )?
Hi, I'm getting unreliable dtmf recognition (it works fine for 4-5 digits, errors (duplicates) on more), when transferred inband from gsm gateway to NT port of quadbri under bristuffed Asterisk. Since Asterisk is claimed to have good dtmf recognizer, I suspect there are some settings to workarouned... I've tried dtmf relax, but didn't help, so I suspect gain settings Is there any other possible cause of unreliable dtmf inband recognition ? Where can I set gain on voice channel (I guess majority of settings under bristuff in zaptel.conf are dummy) ? Any other advice on this problem or similar experience ? Thanks in advance, regards, Rob. ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] GSM ISDN gateway to quadbri NT port under bristuffed Asterisk - where to set gain (I have unreliable inband dtmf recognition )?
Robert Rozman wrote: Hi, I'm getting unreliable dtmf recognition (it works fine for 4-5 digits, errors (duplicates) on more), when transferred inband from gsm gateway to NT port of quadbri under bristuffed Asterisk. Since Asterisk is claimed to have good dtmf recognizer, I suspect there are some settings to workarouned... I've tried dtmf relax, but didn't help, so I suspect gain settings Is there any other possible cause of unreliable dtmf inband recognition ? Where can I set gain on voice channel (I guess majority of settings under bristuff in zaptel.conf are dummy) ? Any other advice on this problem or similar experience ? Thanks in advance, I kind of amazed if works at all when getting DTMF out of a GSM phone. You really shouldn't expect it to. Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
