HI, On Thu, Sep 11, 2025 at 09:31:05PM +0000, Blake Mckeeby via Outages wrote:

* The problem seems to be flow related. A flow (RTP which is a UDP RTP towards a static destination ip & port) that is sent from Comcast Business customer to our cloud has 100% packet loss. Then, a new call is generated creating a new flow and that flow will have 0% packet loss. The issue seems to be affecting ~50% of "flows".

This typically points to some sort of load-balancing across multiple circuits, and one of them being broken - so depending on the ip+port hash of the packet, it's sent left or right, with repeatable results ("all good" or "all bad"). This is typically not "a fiber cut" style of outage but "a router line card claims the port is up, but is not forwarding packets". Very annoying to diagnose if all you monitor is "is the interface status ok?". gert -- "If was one thing all people took for granted, was conviction that if you feed honest figures into a computer, honest figures come out. Never doubted it myself till I met a computer with a sense of humor." Robert A. Heinlein, The Moon is a Harsh Mistress Gert Doering - Munich, Germany gert@greenie.muc.de