nanog mailing list archives
Re: Drops in Core
From: Glen Kent <glen.kent () gmail com>
Date: Sat, 15 Aug 2015 23:01:56 +0530
Is there a paper or a presentation that discusses the drops in the core? If i were to break the total path into three legs -- the first, middle and the last, then are you saying that the probability of packet loss is perhaps 1/3 in each leg (because the packet passes through different IXes). That sounds too aggressive for the middle mile. Dont you think so? On Sat, Aug 15, 2015 at 10:51 PM, Owen DeLong <owen () delong com> wrote:
I would say that the probability of a packet drop at any particular peering point is less than the probability at one of the two edges. However, given that most packets are likely to traverse multiple peering points between the two edges, the probability of a packet drop along the way at one of the several peering points overall is roughly equal to the probability of a drop at one of the two edges. YMMV. OwenOn Aug 15, 2015, at 10:07 , Glen Kent <glen.kent () gmail com> wrote: Hi Bill, Just making sure that i get your point: Youre saying that the probability of packet drop at peering points would roughly match that at the edge. Is it? I thought that most core switches have minimal buffering and really do cut-through forwarding. The idea is that the traffic that they receive is already shaped by the upstream routers. Glen On Sat, Aug 15, 2015 at 10:33 PM, William Herrin <bill () herrin us> wrote:On Sat, Aug 15, 2015 at 12:47 PM, Glen Kent <glen.kent () gmail com>wrote:Is it fair to say that most traffic drops happen in the access layers,orthe first and the last miles, and the % of packet drops in the core are minimal? So, if the packet has made it past the first mile and has "entered" the core then chances are high that the packet will safelygetacross till the exit in the core.Hi Glen, I would expect congestion loss at enough peering points (center of the core) to put it in the same league as noisy cable at the edge. Regards, Bill Herrin -- William Herrin ................ herrin () dirtside com bill () herrin us Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>
Current thread:
- Drops in Core Glen Kent (Aug 15)
- Re: Drops in Core Mike Hammett (Aug 15)
- Re: Drops in Core William Herrin (Aug 15)
- Re: Drops in Core Glen Kent (Aug 15)
- Re: Drops in Core William Herrin (Aug 15)
- Re: Drops in Core Owen DeLong (Aug 15)
- Re: Drops in Core William Herrin (Aug 15)
- Re: Drops in Core Glen Kent (Aug 15)
- Re: Drops in Core Job Snijders (Aug 15)
- Re: Drops in Core Patrick W. Gilmore (Aug 16)
- Re: Drops in Core Job Snijders (Aug 16)
- Re: Drops in Core Patrick W. Gilmore (Aug 16)
- Re: Drops in Core William Herrin (Aug 16)
- Re: Drops in Core Patrick W. Gilmore (Aug 17)
- Re: Drops in Core Glen Kent (Aug 15)
- Re: Drops in Core Justin Wilson - MTIN (Aug 17)
- Re: Drops in Core Patrick W. Gilmore (Aug 17)
- Re: Drops in Core William Herrin (Aug 15)