Ask DrPeering
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Ask Dr. Peering
Dr Peering -
We are looking to start peering. Does transit provider selection have any impact on our peering strategy?
Alton Brown
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In some cases, selecting the right upstream transit provider can increase your chances of obtaining peering. From “The Art of Peering: The Peering Playbook Tactic #5...”
Let’s assume that you buy transit from a Tier 1 ISP (Global Crossing (GLBX) in this example). As a Tier 1 ISP, Global Crossing by definition has access to the entire region through its peering sessions with the other Tier 1 ISPs.
Let’s further assume that GBLX has a less restrictive peering policy than the other Tier 1 ISPs and peers with ISP B, a large regional ISP that you wish to peer with.
Transit Provider Selection can have an impact on peering success.
Transit Provider Selection
Monday, October 26, 2009
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
DrPeering@DrPeering.net
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!
N E W
The Internet Peering Playbook: Connecting to the Core of the Internet
ISBN: 978-1-937451-00-4
Available Now in print, and as a kindle book on Amazon.com and as an ePub on lulu.com and on the Apple iBookStore.
Abstract: One can understand the protocols, the technologies, and the routing algorithms, but that doesn't tell the story. The Internet is a global ecosystem of cooperating and competing networks, strategically interconnected to maximize performance and minimize costs. If you are operating a growing Internet service, it is essential that you understand how the Internet Peering Ecosystem works at the core.
“...destined to be the Internet Peering Bible” – Jeff Turner, InterStream
“Essential Reading.” – Martin Sanne, SEACOM
“Great foundation in understanding the basis for ISP peering,
their interactions, and provides insight into where those relationships are heading.”
– David Mandel, Cisco Systems
“...the benchmark of the most useful technical workshop ever.”–Jaco Muller
