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