Uverse voice incompatible with IP Passthrough on u-verse gateways?
Over at DSL reports, lore has it that u-verse voice is incompatible with IP Passthrough (the nearest thing to bridged mode on AT&T's gateways). See, e.g., this FAQ, which states that "IF you use AT&T uVerse Voice (VoIP) service it is not recommended to put your NVG589/599 Remote Gateway into IP Passthrough mode. IP Passthrough mode has been shown to conflict with uVerse Voice service in which incoming calls may not connect properly resulting in callers hearing an error message."
Is this true? (Searching this forum, I found one thread about incompatibility between DMZ+ on a different modem and voice. My incomplete understanding is that IP Passthrough is closely related, if not identical, to DMZ.) I'd like to use third party router with NVG599 (which requires IP Passthrough) but don't want to lose voice service.
If it is true, does anyone understand why? Any workarounds? One would think the gateway could intercept VOIP traffic.
Thanks for your help.
Not long after posting, came across a thread here that suggests that at least some users had experienced problems with voice calls not being received after setting up third party router using IP Passthrough. But it's not clear to me what the pattern is or if there is any consensus on existence or causes of issue or possible solutions. See: How to put the Motorola NVG589 in 'bridge mode' (or as close as you can).