Quote from: M105 on March 08, 2015, 08:23:20 AM
Support rotary pulse dialing which is still part of the analog telephone standards. This could be made optional in the phone line setup. Telephone collecting is gaining popularity worldwide and having an ATA other than the Grandstream models which support pulse dialing would be great and likely very easy to implement in firmware. Users with older pulse dialing alarm systems would also probably appreciate being able to drop their PSTN lines.
Better yet, provide the ability to dial * and # with the dial hold feature of this device. http://www.dialgizmo.com/ Having that built into the Obihai ATA would provide great value to many users of collectable phones since having to add one almost doubles the cost of the Obi200 alone.
I am building such a device. Rotatone isn't any good. It's very simple to do and it is digital. These VOIP ATAs are not carrier grade. Why use them? I'm forced to do that now that my own DMS was retired. In principle, VOIP sucks. Always did, always will.
Although I have a Nortel Option 11 PBX that performs this function also, it's not practical for most users.
I present a fake dial tone to the user while the ATA is "on hook".
Then I collect the digits dialed allowing for variable speeds (between 8 and 11 pulses) per second
With a break ratio of approx. 60%. Variance here is allowed also according to US/CAN specs.
Dial tone is withdrawn after the first dial pull. Digitone signaling may also be used.
It is store and forward with pretranslation, and will honor the 1ESS sextile (*) = 11 rule with intermediate treatment for vertical service codes. It mimics DMS-100.
So, 1170 will produce a "beep beep", and 1167 will produce a brief stutter in the dial tone before it goes solid again. It will outpulse these in DTMF as *70 and *67 with 1500 ms pauses (digit stringing).
Once "timeout" occurs, the device will seize the ATA and look for dial tone -- then it will outpulse in DTMF. You will not hear the DTMF -- the speech path to the ATA is opened after the outpulsing is complete.
The pretranslator will trigger "line" seizure after the 3rd dial pull if "11" follow the first digit (if the first is a 2 - 9) and add an trailing octothorpe (#) to the outpulse if the ATA supports that.
If the first digit dialed is 1, then it will wait for 10 more digits. If no digit is received after the 8th for 4 seconds, then it outpulses and assumes 1 + 7D (which isn't valid anymore but what the heck).
Any starting digit which is 2 - 9 will timeout 4 seconds after the 7th digit, or immediately after the 10th (for 10 digit locals)
Variable length dialing ...
If the first digit is 0, a 4 second timeout needs to occur (for zero minus calls)
If the first two are 01, a 4 second timeout needs to occur (operator assisted overseas)
If the first three are 011, a 4 second timeout needs to occur (DDD overseas)
This is not a complex digital circuit. Obi is just lazy. The cardinal rule is you always support previous equipment. A switch like DMS 100 supported party lines when very few had them, so it's no excuse.
If dialing DTMF, pressing # invokes timeout. Rotary can't do this of course.