I tried to use a Panasonic 5.8 GHz cordless phone with Vonage box, and\nthen with the Sipura 2100. It shows the same problem with both, that\nwhen I speak loudly into the handset, the person on the other end can\nhardly hear anything. However I can hear the other person fine.\n\nIt is not a problem of the VOIP ATA itself, because a corded phone\nworks fine. It is not a problem of the Panasonic cordless phone\nitself, because with a POTS line it works fine. Rather it is a problem\nof the VOIP ATA / Panasonic cordless combination, but what is really\nstrange is that the problem existed with the Vonage Motorola adapter,\nand still exists with the Sipura 2100.\n\nVonage couldn't figure out what was wrong. I read on their website\nsome mention that people were having trouble with cordless phone using\nVonage ATA, but no mention of why.\n\nSo... why would this happen, and what can be done to fix it? Besides\ngetting a different cordless phone?