nanog mailing list archives
Re: Slashdot: Providers Ignoring DNS TTL?
From: "Robert M. Enger" <enger () comcast net>
Date: Sun, 24 Apr 2005 16:40:50 -0400
Steinar: There is a large body of work from competent and well known researchers that assert the claim. I certainly lack standing to question their results. Empirically, download speeds to home are nearly cut in half (18Mbps) from sources that are subjected to packet reordering along the path. More to the point however, I note that Jay is the author of RFC2100. I think he's just having a little bit of fun. My apologies for belaboring the performance issue. Bob At 04:23 PM 4/24/2005, sthaug () nethelp no wrote:
In your note below you speak of 'moving on to something else' when PPLB comes. PPLB destabilizes TCP. It elicits erroneous retransmissions, squanders capacity and lowers performance.I would actually dispute this. I agree that PPLB will *occasionally* lead to out-of-order packets, which will lead to lower TCP performance *when it happens*. To many customers this is acceptable as long as PPLB gives them improved performance *most of the time*. And this is what we saw very clearly at my previous employer - PPLB worked very well, and gave clearly increased performance, *most of the time*. As mentioned in another message, I don't really believe PPLB is coming. Instead I believe PPLB is something which is probably being *less* used now than a few years ago, since other link bundling methods are more easily available now (than they were a few years ago) - and these link bundling methods occur at a layer below TCP, and are invisible to TCP (no packet reordering problems). Steinar Haug, Nethelp consulting, sthaug () nethelp no
Current thread:
- Re: Slashdot: Providers Ignoring DNS TTL?, (continued)
- Re: Slashdot: Providers Ignoring DNS TTL? Dean Anderson (Apr 23)
- Re: Slashdot: Providers Ignoring DNS TTL? James (Apr 23)
- Re: Slashdot: Providers Ignoring DNS TTL? Niels Bakker (Apr 23)
- Re: Slashdot: Providers Ignoring DNS TTL? Valdis . Kletnieks (Apr 23)
- Re: Slashdot: Providers Ignoring DNS TTL? Bill Stewart (Apr 24)
- Re: Slashdot: Providers Ignoring DNS TTL? Valdis . Kletnieks (Apr 24)
- Re: Slashdot: Providers Ignoring DNS TTL? sthaug (Apr 24)
- Re: Slashdot: Providers Ignoring DNS TTL? Jay R. Ashworth (Apr 24)
- Re: Slashdot: Providers Ignoring DNS TTL? Robert M. Enger (Apr 24)
- Re: Slashdot: Providers Ignoring DNS TTL? sthaug (Apr 24)
- Re: Slashdot: Providers Ignoring DNS TTL? Robert M. Enger (Apr 24)
- Re: Slashdot: Providers Ignoring DNS TTL? Steve Gibbard (Apr 24)
- Re: Slashdot: Providers Ignoring DNS TTL? Stephen J. Wilcox (Apr 25)
- Re: Slashdot: Providers Ignoring DNS TTL? Dean Anderson (Apr 29)
- Re: Slashdot: Providers Ignoring DNS TTL? Christopher L. Morrow (Apr 29)
- Re: Slashdot: Providers Ignoring DNS TTL? Dean Anderson (Apr 29)
- Re: Slashdot: Providers Ignoring DNS TTL? sthaug (Apr 30)
- Re: Slashdot: Providers Ignoring DNS TTL? Dean Anderson (Apr 30)
- Re: Slashdot: Providers Ignoring DNS TTL? Dean Anderson (Apr 30)
- Re: Slashdot: Providers Ignoring DNS TTL? James (Apr 30)
- Re: Slashdot: Providers Ignoring DNS TTL? Dean Anderson (Apr 30)