RE: what is happening. 2 possibilities that we've already had to deal with, since they're on a GX switch platform: PNNI doesn't work between the GX and the Lucent PSAX on any but (I believe) the most current rev of GX *and* PSAX software, and there's a bug on the GX platform which causes "directed PVCs" to stop passing traffic until manually reset. A final option is that we've had a couple of processor boards in the GX fail and, instead of passing control over to the redundant board, the switch goes off-line and has to be manually reset. I'm unsure if this is a hardware or software bug. RE: upgrades. It is pretty safe to assume that most GX customers are going to need to do an upgrade in the near future. We just finished one, but were able to do it incrementally. It was the third we've had to do in 6 mos. to iron out GX-PSAX and management problems. I'm not sure what would prompt Qwest to upgrade the whole network at once, though. Cheers. -travis p.s. -- go easy on me ... i'm not the ATM guru. I'm just reporting what has come up during engineering discussions with Lucent. On 23 Mar 2001, Sean Donelan wrote:

Routing may be weirder than normal this evening. Qwest is upgrading their Lucent ATM switches to fix a bug, and needs to shutdown their entire ATM backbone for a couple of hours. Qwest hasn't responded to my e-mails asking what is happening, but other ISPs have outlined alternative routes they will be using. Most will try to maintain service by additional peering, deaggregated routes, or temporary third-party transit.

Other providers use Lucent ATM switches. I don't know if they will also need to upgrade their networks at some time in the future to fix the same problem.