What is the issue with re-marking and OoO packets?

This question, taken from the CCDE Written Outline, taught me something new. Since that’s the purpose of any certification, I welcome these interesting, if somewhat vague, questions. The main issue with re-marking and Out-of-Order packets can be found in RFC3819: (aka BCP89) “reordering does come at a cost with TCP as it is currently defined.Continue reading “What is the issue with re-marking and OoO packets?”

RIPv2 advantages & disadvantages

RIPv2 gets a bad rap, in my opinion, because it still has some suitable network topologies that it works well for. It’s kind-of like the visceral reaction some people have towards static routing. There’s no ‘right’ answer for most of these design types of decisions, only ‘better’ answers. As for RIPv2, let’s see some ofContinue reading “RIPv2 advantages & disadvantages”

Took the CCDE Practical Exam Today

14 people in Chicago and 14 people in London took the test today. First impressions: 1. It’s very, very difficult2. I don’t think it’s “impossible” However, I will caveat this with – I don’t really think I have a chance at passing. In all, I had fun taking it. I’m mostly relieved to have hadContinue reading “Took the CCDE Practical Exam Today”

Content Networking & Satellite Communication

I work primarily on satellite communications systems. TDMA and FDMA satellite networks present interesting data communications issues, since our RTT is usually on the order of 700ms. One thing we’ve been experimenting with is caching of data. The NME-WAE product works well for caching, but can occasionally ’cause’ problems that are exacerbated by virtue ofContinue reading “Content Networking & Satellite Communication”