Ask DrPeering

   Ask Dr. Peering

Transit Provider Selection can have an impact on peering success.

When you request peering with ISP B, they will most likely say, “No thanks, I already hear your routes through a peer (GLBX).”

So now let’s assume that you instead decide to purchase transit from the most restrictive Tier 1 ISP, and let’s assume (for this example) that this would be Sprint.

Summary: A strategy to maximize your chances of obtaining peering by buying transit from the most restrictive Tier 1 ISP you can find.

Dr Peering


So, in addition to the “already hears your route” denial of peering, ISP B will see peering with you as endangering its peering relationship with GBLX because of its peering ratio balance.

Of course, peering with GBLX’s downstream CUSTOMER also may irritate GBLX, but this doesn’t seem to play out as strongly.

Since Sprint does not peer with ISP B, there is no such disincentive for peering with you.

The Ratio Issue.

There is another subtle issue here surrounding the impact of peering with you from ISP B’s perspective. 

Let’s assume that you are content heavy, with more traffic to send to ISP B than you will receive from ISP B. 

ISP B considers what will happen if they peer with you, ISP A. In this case, ISP B will be shifting this traffic from its peer GBLX to its direct peering session with you (as shown below).  Therefore, ISP B will not be pulling as much traffic as it used to from GBLX - in other words, it will appear to be pushing more traffic to GBLX than it used to.  If ISP B is near the cusp of managing its maximum 2:1 ratio with GBLX, peering with you may push it over the 2:1 ratio limit and threaten its peering with GBLX!

The 2014 Internet Peering Playbook

In Print

and for the Kindle:

The PDF, ePub and

.mobi files are

also available as a

perpetually updated

DropBox share:

Price: $9.99

and in French!

The 2013 Internet Peering Playbook

also available for the Kindle:

and the ipad