There are multiple ways this outage can impact CL 911 service not just related to IP. Here are a few of them:
1. You have a POTS line and you dial 911 which gets to your central office but the CO switch had no trunks out, either because they were TDM but riding one of the optical carriers or IP based. Both go down when the optical mux chokes. 2. 911 center is probably connected to multiple COs (usually at least two) but since this outage was nationwide it is very likely that adjacent COs could have lost transmission trunks isolating the 911 center. 3. If you are a cellular customer, that data is getting backhauled to a central office and then getting inserted into the same CO switches that lost their transmission capacity. It is important to remember that a lot of stuff is using IP for transport but the IP network is also controlling the L1 infrastructure. In this case it looks like the IP network transmitted bad control data to the underlying fiber network. Steven Naslund Chicago IL >Guys, >While reading CL network down impacting 911 services, was trying to get more >information about how does this network looks like. From end user to center, I >guess VOIP is used. Wondering what is the communication method >from >Emergency service center to end units (Police, Fire or any other services). Do >they also use IP ? or its Still Radio only ? if it is IP, do they use Unicast >or multicast or broadcast ? > >Tried googling, but did not get much information. Any insight would be >appreciated. > >Thanks >Mankamana
