Peering

A settlement-free interconnection between two networks that agree to exchange traffic directly, bypassing transit providers and reducing cost and latency.

Last updated: April 22, 2026

What is peering?

Peering is a direct interconnection between two networks that agree to exchange traffic with each other without paying transit fees. Each network carries the cost of its own ports and cross-connects; the traffic itself flows settlement-free. Peering reduces costs, improves latency (fewer hops), and gives each side more control over how its users reach the other side's services.

Public vs. private peering

Private peering is a dedicated cross-connect between two networks — a physical fiber or a virtual circuit inside a data center — carrying traffic only between those two parties. It scales to very high bandwidth (100 Gbps and up) and is the standard between large eyeball ISPs and major content providers.
Public peering happens at an IXP (internet exchange point). Each participant has a single port on a shared fabric and can exchange traffic with any other participant via BGP sessions over that fabric. Public peering is cheaper to set up and is where thousands of smaller networks meet.

Peering vs. transit

A production network usually has both: peering with networks it exchanges a lot of traffic with directly, and transit from one or more upstream providers to reach everything else. Peering is restricted by "peering policies" — requirements on traffic ratios, geographic presence, and network size — while transit is a commercial service open to anyone who pays.

You can see a network's peering relationships and upstream transit by looking up its ASN via our WHOIS lookup tool.

Frequently Asked Questions

The traffic exchange itself is settlement-free — neither side bills the other for bandwidth used. Each network does pay for its own port at the IXP (typically a few hundred dollars per Gbps per month) or its own private cross-connect (cabling fee, port fee). For two well-matched networks, peering is dramatically cheaper than buying transit at the same volumes. Disputes about "balanced" traffic ratios (when one side sends much more than the other) sometimes lead to "paid peering" arrangements that blur the line with transit.

Transit is a paid service — you buy access to the entire internet through an upstream provider, billed per bandwidth used. Peering is a settlement-free exchange — you exchange traffic only between yourself and the peer (and the peer's direct customers), not the rest of the internet. A typical production network buys transit from a few upstreams to reach everything, plus peers directly with networks it exchanges large volumes of traffic with to reduce cost and latency.

A peering policy is a network's published criteria for who they will peer with. Common requirements include minimum traffic volume (a 100 Mbps minimum is typical), geographic presence at multiple IXPs, balanced traffic ratios (typically no more than 4:1 between the two parties), and the prospect of mutual benefit. Policies range from "open" (peer with anyone) to "selective" (case-by-case) to "restrictive" (only peer with networks of similar size). Most large eyeball ISPs run restrictive policies; most CDNs and content networks run open policies because peering reduces their transit costs.

Each network hop adds a few milliseconds of latency. Without peering, a request from your ISP to a content provider might traverse 4-6 transit hops; with direct peering it traverses just 1. On transcontinental traffic this can cut latency by 30-80 ms, which is the difference between a snappy web page and a sluggish one. For real-time traffic (gaming, voice, video), shorter peering paths are why major game and video providers invest heavily in private cross-connects with eyeball ISPs.

Sometimes — but rarely on the same terms. Big eyeball ISPs typically run restrictive peering policies and require minimum traffic volumes that small networks cannot meet on their own. The realistic path for small networks is to peer at large IXPs where the big networks have an open or semi-open route-server policy, join through a transit provider that already peers, or connect via a community route server like the ones at LINX, DE-CIX, or AMS-IX. CDNs are generally much more open to peering with anyone.

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