FAQs & Troubleshooting FAQ Search Results MFC-7820N Not your product? Search by FAQ ID number Search Back to FAQs & Troubleshooting. 2 Results 1.faq00002123_026 I'm using Voice Over Internet Protocol (VoIP) and am having problems sending faxes. 2.faq00002123_027 I'm using Voice Over Internet Protocol (VoIP) and am having problems receiving faxes. FAQs & Troubleshooting