Peering relationships are important for the smooth running of the internet because they enable data to pass between different networks, ensuring that users can access content and services without interruption.
Without peering agreements, Internet Service Providers (ISPs) would need to pay service fees to other networks that data they are sending travels through.
What are the different types of peering?
Peering takes two main forms, public and private peering.
Public peering relies on public internet infrastructure, and often on internet exchange points (IXPs).
IXPs collect service revenue from networks in order to facilitate them meeting and agreeing to exchange traffic.
Once connected to an IXP, a network can peer with all other networks that are also connected. Some networks connected to IXPs will have an open peering policy, which means that they are willing to accept a peering agreement with any other network.
Others will have certain requirements before an agreement is reached, which could include things like minimum traffic exchanged or number of peering points.
Networks can also establish direct connections between each other outside of public exchange points. This is known as private peering.
Private network interconnections are established to facilitate dedicated and private data transfers between two networks, either through a physical connection or through a virtual connection via the cloud.
How do you choose between public and private peering?
Public and private peering each come with their owns pros and cons. For one network to decide whether it will peer with another in a public or private manner depends on the specific requirements of data exchange between them.
Because public peering takes place at IXPs it opens a large pool of potential networks to peer with. It also makes it easy to connect with them because the IXP is providing the necessary infrastructure.
However, because it uses public infrastructure, latency will be higher, and resilience lower as an additional point of failure is added in the form of the IXP.
In cases where it easy to do so, such as two networks being co-located in the same data centre, private peering can be considered.
Private peering can also be considered when large volumes of data are required to be transferred between the two networks, or if latency, security, and resiliency is particularly sensitive.
Unless one of these conditions is met, it is more likely that public peering will be preferred due to the increased complexity and cost of private peering.
Why is peering cost-effective?
Without peering agreements, transit networks are required for data to pass from point A to point B. Service fees are required for the use of these transit networks. As discussed, the cheapest way to exchange traffic between networks is through public peering.
But private peering can also offer cost benefits over using a transit network. Private peering is more expensive to set up because it requires the two networks to connect directly rather than rely on infrastructure from the IXP, but it could offer cost savings in the long term, as service fees to the IXP are not required.
How does peering reduce latency?
Avoiding reliance on a transit network enables direct data transmission which in turn leads to lower latency, and improved network reliability.
This is even more true for private peering, which establishes an even more direct link between the two networks, and as such reduces latency further.
An example of why network peering matters
I3d.net is an infrastructure company focused on supporting digital experiences, online gaming and virtual reality.
“Latency and a reliable connection are non-negotiable for developers of real time applications and multiplayer video games, which is why it is so important to choose your compute resources with network considerations in mind,” i3D.net says.
After realising that players of online games in the Middle East were suffering with higher ping than in other regions and receiving a worse quality of service as a result, i3D.net established a relationship with DE-CIX, an independent company that operates IXP’s in the region.
i3D.net’s network team worked on bringing major telecom operators and system integrators to the UAE internet exchange and thus facilitating these peering agreements.
This has allowed for more direct connections, without traffic having to take an unnecessarily long route through Europe.
“Latency has been reduced by 80% or more compared to before,” Martijn Schmidt, VP network at i3D.net says. “Now, with the lower latency, combined with local availability of many games in the region, user satisfaction is on the rise.”
