***** To join INSNA, visit http://www.insna.org ***** Well, usually (see Pastor-Satorras & Vespignani (2004). Evolution & Structure of the Internet. Cambridge: Cambridge University Press), the formula $<l> \sim \logN / \log<k>$ is attributed to B. Bollobas (1981) and Bollobas & de la Vega (1982) - I can send you the detailed references if you wish. To be more accurate, Bollobas has considered the diameter of a random k-regular graph and showed that $\diam(G_{N,k-reg} \sim \logN / \log(k-1)$ and $\diam(G_{N,k-reg} \sim <l>$, "with high probability" asymptotically for $N$. I'm afraid this does not answer your question. In any case, you have to check out the detailed algorithms used in the numerical computations of these quantities, which are implemented in the software packages you're using. --Moses Boudourides _____________________________________________________________________ SOCNET is a service of INSNA, the professional association for social network researchers (http://www.insna.org). To unsubscribe, send an email message to [log in to unmask] containing the line UNSUBSCRIBE SOCNET in the body of the message.