Power supply! Old POTS is remote-power-suplied, so the phone will work for hours, days or even weeks from remote battery power. In my area, one mobile network was off after 4h, the other after 10h, but my good-old analogue telefone did work all the time during an 40h power outage (it was 11 years ago). Juergen.
-----Original Message----- From: Nathan Eisenberg [mailto:nathan@atlasnetworks.us] Sent: Monday, February 28, 2011 6:33 PM To: NANOG list Subject: RE: What vexes VoIP users?
Some provider woes:
FAX over VOIP is a PITA. I've not yet seen an ATA or softswitch that handled it reliably.
E911 for mobile devices sucks. Regulations, and the E911 system, do not seem to have the flexibility for handling this in a seamless way.
Call routing (on a more global scale) sucks. Keeping calls pure IP is sexy, but the routing protocol for it is nonexistent (and please don't say ENUM).