Google Global B4 / Andromeda Backbone
Google's private inter-datacenter software-defined WAN carrying vast user and cloud traffic globally
Open it on the earth: cut a link, lose a siteWorkbook (DC Sim template v1.4)
The story
Google's internal inter-datacenter WAN, known historically as B4, revolutionized computer networking by proving Software-Defined Networking (SDN) at planetary scale using custom OpenFlow switches and centralized traffic engineering. Running over thousands of route-kilometers of private terrestrial dark fiber and trans-oceanic cables—including Curie, Dunant, Grace Hopper, and Unity—it connects hyperscale server farms across North America, Europe, Asia, and South America to power Search, YouTube, Workspace, and Google Cloud Platform services.
Notable
- Pioneered production Software-Defined Networking (SDN) at scale through the B4 private WAN architecture.
- Carries traffic across Google-owned subsea cables including Dunant, Grace Hopper, Curie, and Equiano.
- Dynamically balances massive data replication flows alongside interactive cloud services with central traffic engineering.
- Links hyperscale mega-campuses across North America, Europe, Asia, and South America.
Sites
| Code | Place | Role | Provider |
|---|---|---|---|
| CBF | Council Bluffs, United States | primary | |
| DLS | The Dalles, United States | primary | |
| HAM | Google Hamina data center | primary | |
| EEM | Eemshaven, Netherlands | primary | |
| CHG | Changhua County, Taiwan | primary | |
| SGP | Jurong West, Singapore | primary | |
| QLC | Quilicura (Santiago), Chile | primary |
Links
| From | To | Type | Capacity | Length | Year | Protected | Est. one-way latency |
|---|---|---|---|---|---|---|---|
| CBF | DLS | backbone | 12,000 Gbps | ≈ 2,091 km (great circle) | — | yes | 32 ms |
| CBF | EEM | submarine | 10,000 Gbps | ≈ 7,166 km (great circle) | — | yes | 75 ms |
| EEM | HAM | terrestrial | 8,000 Gbps | ≈ 1,451 km (great circle) | — | yes | 22 ms |
| DLS | CHG | submarine | 8,000 Gbps | ≈ 10,082 km (great circle) | — | yes | 115 ms |
| CHG | SGP | submarine | 8,000 Gbps | ≈ 3,108 km (great circle) | — | yes | 38 ms |
| DLS | QLC | submarine | 6,000 Gbps | ≈ 10,139 km (great circle) | — | yes | 120 ms |
Latency marked ≈ is our estimate from the great-circle distance × 1.5 at 5 µs per km, not the operator's figure.
Sources
- B4: Experience with a Globally-Deployed Software Defined WAN · Google / ACM SIGCOMM · 2013-08-12
- Google Cloud Locations and Global Network · Google · 2024-01-01
Part of the open famous data centers dataset (CC BY 4.0). Updated 2026-10-15.
What is Google Global B4 / Andromeda Backbone famous for?
Google's private inter-datacenter software-defined WAN carrying vast user and cloud traffic globally
How many sites and links does Google Global B4 / Andromeda Backbone have in this dataset?
7 sites and 6 links, of which 0 are recorded as not protected. Figures are from the public sources listed on the page.