Global Internet service provider GTT Communications is buying London-based Interoute, operator of one of Europe’s largest independent fiber networks and cloud networking platforms, for about $2.3 billion in cash.

The acquisition will add a 44,700-mile fiber network in Europe, 15 data centers, 17 virtual data centers, and 51 colocation facilities, enhancing GTT’s cloud connectivity platform. GTT said the deal will expand its network to interconnect 126 cities across 29 countries. In addition to infrastructure, GTT gains Interoute’s global sales, operations, and customer service employees.

The purchase also brings GTT more than 1,000 new enterprise and carrier clients, primarily headquartered in Europe.

Virginia-headquartered GTT claims the acquisition will strengthen its position in software-defined wide area networking (SD-WAN). GTT last year launched its managed SD-WAN service using VeloCloud’s technology.

Interoute uses Silver Peak’s overlay technology for SD-WAN and for WAN optimization.

GTT expects the transaction to close in three to six months.

In June 2017, GTT bought Global Capacity for about $161 million. GTT touted that acquisition as a way to boost its nascent SD-WAN service for its enterprise customers. GTT said it found Global Capacity appealing because of its last-mile connectivity assets.