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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Traffic Engineering
On Thu, Sep 18, 1997 at 12:55:37PM -0400, Sean M. Doran wrote: > "Jay R. Ashworth" <[email protected]> writes: > > > Are there any major potholes in this theory that I'm missing? > > Well, you have two technical problems to solve: firstly, > the same numbering problem that anyone else has, > viz. addresses will change. [ Looks at From: address ] Oh. Hi, Sean. :-) > Secondly, you have a traffic > attraction/traffic dispersion problem for non-local > connectivity. You also have to provide better > value-for-money than the classical hierarchy-of-providers > model your competitors will be using. Probably. But, given the relative pricing of T-3s and T-1s, I don't think this will be that hard to do, especially if wireless last mile picks up as fast I I expect it will... > The "classical" approach is to renumber to solve the first > case and do the oh-so-fun BGP tricks Dennis Ferguson > described here a couple of incarnations ago. > > A better approach to both problems is to use NAT to deal > with the renumbering issue, and large-scale NAT to deal > with your border problem (you not only want to reduce the > number of prefixes you advertise outbound, and use the DNS > to offer back different topolical locators (i.e., IP > addresses) for the things connected to you, but you also > want to reduce the amount of information you take in from > the outside world). Well, yeah, but the delights of NAT in a two or three customer-level deep commercial environment are an administrative problem I don't think I even want to go near... > To deal with connectivity failures outside the NATs > themselves you build tunnels through working inside or > outside infrastructure between your NATs. This is > straightforward and is what is done now. > > Dealing with the failures of the NATs themselves requires > synchronized or deterministic address mappings, > NAT-friendly higher-layer protocols, and a simple IGP. Um... I haven't gotten quite this far down the pike, yet, Sean. :-) > With some performance-affecting trade-offs you can deal > with many NAT-unfriendly higher-layer protocols in various > ways too, mostly by sharing state information among your > border NATs. Sometimes I feel like I'm at a multi-level marketing seminar... :-) Cheers, -- jra -- Jay R. Ashworth [email protected] Member of the Technical Staff Unsolicited Commercial Emailers Sued The Suncoast Freenet "People propose, science studies, technology Tampa Bay, Florida conforms." -- Dr. Don Norman +1 813 790 7592
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