<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">On 2 Dec 2015, at 2:14 PM, Shane Short <<a href="mailto:shane@short.id.au" class="">shane@short.id.au</a>> wrote:<br class=""><div><br class=""><blockquote type="cite" class=""><div class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); float: none; display: inline !important;" class="">Hijacking this a little bit, what do people actually look for when you're deciding what IXP you should peer with? Is it table size, traffic volume, or a specific peer that's on the fabric?</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""></div></blockquote></div><div class=""><br class=""></div>Think about which metrics you pay for. It’s probably link capacity.<div class=""><br class=""><div class="">Run netflow on your transit, get a real breakdown of %’age traffic source/destination by ASN.</div><div class=""><br class=""></div><div class="">Then you can start making educated judgements about which ASNs you need to peer with to remove each AS-load of traffic from your transit. “I’m paying $x per megabit per month for transit, I’m getting Y megabits from AS nnnn, so I can remove $x * Y from my transit bill if I find that AS somewhere else.” Extrapolate for time based on your growth curves to see how much you’ll be saving at the same time next year too. Make a spreadsheet, a row for each ASN, with megabit and dollar numbers next to them.</div><div class=""><br class=""></div><div class="">Then you can look at how much it’ll cost to reach the IXs where those ASs congregate. Sum up the transit dollar savings for all the ASNs you think you can meet on peering. If the cost of connecting the required number of megabits to the IX is less than the amount saved on your transit, it’s worth going to that IX.</div><div class=""><br class=""></div><div class="">It should be a pretty objective business judgement based on hard numbers. </div><div class=""><br class=""></div><div class="">Once you’ve committed to an IX, connect to as many ASs as you can. Don’t be too choosy: You aren’t a monopoly incumbent so you don’t need exclusive peering policies. Every megabit you exchange with the IX is a megabit you don’t have to carry on transit.</div><div class=""><br class=""></div><div class="">You can also get a non-tangible advantage by include IXs where you can see ASNs you already reach on peering elsewhere: Won’t make any difference to your transit bill, but will probably make your connectivity more reliable. If you get enough savings from other ASNs to justify reaching multiple IXs, you can get diversity to well connected content sources at pretty minimal cost. That’ll bring value to your business too, in differing amounts heavily dependent on your business model.</div><div class=""><br class=""></div><div class="">Remember to have enough transit capacity accommodate a failed IX: The traffic has to go somewhere, you don’t want to be the worst ISP in the world just because Equinix has a bad hair day. 95th percentile billing is the way to go here, carry headroom and only pay for it if you need it, and get automatic price reductions for each ASN you move to peering.</div><div class=""><br class=""></div><div class="">Not rocket science, just start with hard numbers instead of wishy-washy feelings, and proceed rationally.</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""> - mark</div><div class=""><br class=""></div><div class=""><br class=""></div></div></body></html>