On Wed, Feb 25, 2004 at 09:44:51AM -0800, David Meyer wrote: > Jared, > > >> I keep hear of Frame-Relay and ATM signaling that is going > >> to happen in large providers MPLS cores. That's right, your "safe" TDM > >> based services, will be transported over someones IP backbone first. > >> This means if they don't protect their IP network, the TDM services could > >> fail. These types of CES services are not just limited to Frame and ATM. > >> (Did anyone with frame/atm/vpn services from Level3 experience the > >> same outage?) > > Is your concern that carrying FR/ATM/TDM over a packet > core (IP or MPLS or ..) will, via some mechanism, reduce > the resilience of the those services, of the packet core, > of both, or something else?
I'm saying that if a network had a FR/ATM/TDM failure in the past it would be limited to just the FR/ATM/TDM network. (well, aside from any IP circuits that are riding that FR/ATM/TDM network). We're now seeing the change from the TDM based network being the underlying network to the "IP/MPLS Core" being this underlying network. What it means is that a failure of the IP portion of the network that disrupts the underlying MPLS/GMPLS/whatnot core that is now transporting these FR/ATM/TDM services, does pose a risk. Is the risk greater than in the past, relying on the TDM/WDM network? I think that there could be some more spectacular network failures to come. Overall I think people will learn from these to make the resulting networks more reliable. (eg: there has been a lot learned as a result of the NE power outage last year). > >> We're at (or already past) the dangerous point of network > >> convergence. While I suspect that nobody directly died as a result of > >> the recent outage, the trend to link together hospitals, doctors > >> and other agencies via the Internet and a series of VPN clients continues > >> to grow. (I say this knowing how important the internet is to > >> the medical community, reading x-rays and other data scans at > >> home for the oncall is quite common). > > Again, I'm unclear as to what constitutes "the dangerous > point of network convergence", or for that matter, what > constitutes convergence (I'm sure we have close to a > common understanding, but its worth making that > explicit). In any event, can you be more explicit about > what you mean here? Transporting FR/ATM/TDM/Voice over the IP/MPLS core, as well as some of the technology shifts (VoIP, Voice over Cable, etc..) are removing some of the resiliance from the end-user network that existed in the past. I think that most companies that offer frame-relay which also have a IP network are looking at moving their frame-relay on to their IP network. (I could be wrong here clearly). This means that overall we need to continue to provide a more reliable IP network than in the past. It is critically important. I think that Pete Templin is right to question peoples statements that "nobody died because of a network outage". While I think that the answer is likely No, will that be the case in 2-3 years as Qwest, SBC, Verizon, and others move to a more native VoIP infrastructure? A failure within their IP network could result in some emergency calling (eg: 911) not working. While there are alternate means of calling for help (cell phone, etc..) that may not rely upon the same network elements that have failed, some people would consider a 60 second delay as you switch contact methods too long and an excessive risk to someones health. I think it bolsters the case for personal emergency preparedness, but also spending more time looking at the services you purchase. If you are relying on a private frame-relay circuit as backup for your VPN over the public internet, knowing if this is switched over an IP network becomes more important. (I know this is treading on a few "what if" scenarios, but it could actually mean a lot if we convert to a mostly IP world as I see the trend). - jared -- Jared Mauch | pgp key available via finger from [EMAIL PROTECTED] clue++; | http://puck.nether.net/~jared/ My statements are only mine.