North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: ATM (was Re: too many routes
On Fri, 12 Sep 1997, Vadim Antonov wrote: > Actually, 4000 miles is a very reasonable estimate for a cross-country > path physical length. That's why i took it as such without much > arguments. I am thinking it may be, we are getting together timings, and people are reporting the runs. The calculations are getting lower as we go. It is starting to look 30 ish. I agree this is not as significant as I thought it was going to be.... However, it is interesting to close in on. ;) > > > This implies that 39% of the actual timing is overhead. > > Hey, did you ever measure delay on a real cross-country fiber? > Did you compare that with pings between attached routers? > (Hint: i used to work for a long distance carrier). I do. And have for a while. That doesn't mean anything one way or another. Why don't we knock off the I am , I was, and I will be's and lets get the answer from data coming in. ;) This thread has been joined by some rather interesting people. All of which humble me, to be sure. (not that it is a difficult thing ;) The interesting thing is, most of these people are interested enough, that the data is coming in... I suspect, we may be able to get to a "reasonably" accurate ratio, but it should be interesting. Aren't you curious ? Or, do you have current data ? If so , post it. > > 74 ms you quoted is actally a nice RTT, for a loaded network > particularly. The first SprintLink's DS-3 between DC and > Stockton, CA had 80 ms (that's clearline, w/o any routers in the We have one down into the mid 60's now. Check the archive. > Now, would you care to explain how 0.3ms delay per router can > make things worse, considering that the average number of > _backbone_ hops for inter-provider trace is about 6? > At each juncture , layer 3, exists an opportunity for routing interaction. This is "for better" or "for worse". The better, is not what I am concerned with.... If indeed a router, participating in full tables, only introduces .3 ms delay, on a median, then the market bodes well.. But, I am concerned with the "distribution of the curve" so to speak. How -wide- is it.... How do we narrow it ? > --vadim >
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