We've discovered that an AT&T tandem switch in Toledo, OH, is overloaded. Calls from an Illinois cell phone to an Illinois number (somehow) get routed through Anaheim, CA, before coming here. Sometimes the calls are sent to the overloaded switch (and thus fail), while at other times they're sent to Chicago (and succeed). My tech spent over an hour on the phone with AT&T, placing test calls while they ran traces to diagnose the issue. Someone is supposed to be running a script to remove Toledo from their routing, but it's unknown how long that will take. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange DNA Communications ----- Original Message ----- From: "Mike Hammett via VoiceOps" <voiceops@voiceops.org> To: "voiceops" <voiceops@voiceops.org> Sent: Tuesday, September 30, 2025 1:00:55 PM Subject: [VoiceOps] AT&T NOC Does anyone have a contact at the AT&T NOC? We're on the receiving end of "All Circuits Are Busy" calls. I've put in a ticket to the tandem operator, but Frontier is slow to respond or resolve issues. I tried reaching out to AT&T's NPAC contacts, but they just direct my team to the main consumer support line. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange DNA Communications _______________________________________________ VoiceOps mailing list -- VoiceOps@voiceops.org https://lists.voiceops.org/postorius/lists/voiceops.voiceops.org/ To unsubscribe send an email to voiceops-leave@voiceops.org