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| Author | Topic |
| Daveman_750 Tl Posts: 86 USA | Posted - 5/16/2000 4:01:35 PM     For a V.34 call, GOOD SNR should be around 30 at least. For V.90, around 40 at least. Even if you have a V.90 modem, if you are making a V.34 call you should only expect SNR in the 30s. The theoretical noise floor for the codec used in the U.S. is 39.5 dB, but most codecs have an ACUTAL noise floor of about 35dB. Add in analog noise and its about 30 dB. In V.90, since there is no quantization error, SNR can be higher than the noise floor of the codec. An SNR of 11 to 15, although I am not sure, should probably make voice calls sound pretty hard to hear. This is why I think your telco is obligated to do something about it. They provide voice grade lines. |
| Mary Tl Posts: 6 USA | Posted - 5/16/2000 4:56:44 PM Dave.....modem check shows V.34, but I have a V.90.....how do I change it so that's what it shows? thanks, Mary thanks for any help |
| shano64 Tl Posts: 16 | Posted - 5/16/2000 6:15:14 PM Dave, When Mary and I graduate from your online class of "modem 101", do we get a certificate? |
| Daveman_750 Tl Posts: 86 USA | Posted - 5/16/2000 6:22:23 PM Ahh, yes, that's one of the hidden costs of this class: You have to PAY for a certificate. |
| Daveman_750 Tl Posts: 86 USA | Posted - 5/17/2000 2:56:37 PM If your modem can't get a good V.90 connect it will fall back to V.34. Its still a V.90 modem. If you complained about NOISE IN VOICE CALLS and your telco said your line was fine, then it may be that they tested a diff jack and you need to get better wiring. This goes for Shano and Mary as both or your SNRs suck. |
| shano64 Tl Posts: 16 | Posted - 5/19/2000 6:35:37 PM The telco came and gone. They said there was no problems. I went over my wiring yesterday just to make sure everything is alright, but I feel that a definate problem is the 2 phones on the same line. One is all the way across the house and to the 2nd floor, and the other is to the kitchen. The line from my computer goes to a hole in the floor about a foot away, and then to the posts about 4 feet away. My SNR today was 19. I'm in the middle of installing a teleprotector to cut off the other lines. Who do I send the check to for the classes..heehee |
| v.Richard Tl Posts: 6222 USA | Posted - 5/20/2000 5:23:34 PM With a 3Com modem, you should do the a/d conversion check. If you fail the test, you could try and charm the telco into providing you with better lines.  Link Aloha, |
| NarH Tl Posts: 1 USA | Posted - 5/29/2000 9:50:32 PM If you dial 1 on a regular phone and hear static and it's intermittent then you have to call the phone company repair number.
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