This article is relevant to the DrayTek 2800 series routes, which includes the DrayTek Vigor 2800, DrayTek Vigor 2820 and DrayTek Vigor 2850 models.
If using the SureVoIP Hosted service, you may need to disable SIP ALG on your DrayTek router.
To do so, you may need to install Telnet onto your Windows Vista/7 computer.
sys sip_alg 0 [Enter]
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