FAQs & Troubleshooting FAQ Search Results MFC-620CN Not your product? Search by FAQ ID number Search Back to FAQs & Troubleshooting. 2 Results 1.faq00002123_011 I'm using Voice Over Internet Protocol (VoIP) and am having problems sending faxes. What can I do? 2.faq00002123_012 I'm using Voice Over Internet Protocol (VoIP) and am having problems receiving faxes. What can I do? FAQs & Troubleshooting