Cross connect: the network shortcut your infrastructure deserves

Imagine living in a building where all residents have to walk down the main street to visit their neighbors on the same floor. Absurd? Yet this is what many companies do with their data: they send it over the public internet to reach a partner hosted in the same room. A cross connect is simply the door between apartments, a direct, private, and ultra-fast connection between two pieces of equipment within a data center.

One cable, two servers, zero extra steps

A cross connect, sometimes referred to as a “remote connection” or “cross connection,” is a physical link (fiber optic or copper) that directly connects two racks, two servers, or two separate infrastructures within the same data center. In practical terms, it is a cable that runs from your rack to that of a telecom operator, cloud provider, or business partner, without ever using the public internet.

This connection is usually established via the Meet-Me Room (MMR), the data center's hub. All the fiber and copper cables from the various racks converge in this secure room, where interconnections between customers are made. Think of the MMR as the building's marshalling yard: thousands of cables arrive there to be connected to each other according to individual needs.

Key point: The cross connect does not require any intermediate active equipment. It is a passive, point-to-point connection that allows both ends to manage the protocol and throughput they want.

Why not just use the internet?

The question is worth asking. After all, the internet works, doesn't it? Technically, yes, but the comparison quickly turns in favor of cross connect on several key criteria.

Latency: every millisecond counts

When your data travels over the internet, it goes through an average of 10 to 15 network “hops,” routers, switches, and exchange points before reaching its destination. Each hop introduces a few milliseconds of delay. For a standard connection, expect between 50 and 200 ms of latency.

With a cross connect in the same data center? Data only makes 1 or 2 hops and latency drops below a millisecond. In the high-frequency trading sector, this difference can represent several thousand euros per transaction. For a traditional business application, it simply guarantees smooth responsiveness.

Security: Your data never leaves your place

On the public internet, your data is exposed. It passes through infrastructure that you do not control, goes through shared exchange points, and can theoretically be intercepted. Cross connect eliminates this risk: the connection remains physically confined within the data center. No external transit, no exposure to man-in-the-middle cyberattacks.

Stability: no more traffic jams

The public internet is subject to traffic fluctuations. During peak hours, congestion slows down exchanges. Certain nodes may fail, forcing unpredictable rerouting. Cross connect, on the other hand, offers dedicated and constant bandwidth. Your connection no longer depends on the state of the global network.

The cost: less expensive than you might think

Paradoxically, cross connects are often cheaper than internet connections of equivalent quality. There are no local loop charges, transit costs, or subscriptions to intermediary operators. Most data centers charge a few dozen euros per month for a cross connect, which is far less than the cost of a dedicated connection via a telecom operator.

The different types of cross-connects

Not all cross connects are the same. The choice of medium depends on your requirements in terms of throughput, distance, and budget.

Single-mode optical fiber

It is the champion of distance and throughput. Single-mode fiber (SMF) uses an optical core that allows light to be transmitted over several kilometers without degradation. It supports speeds of up to 100 Gbps and beyond. It is the preferred choice for critical links, interconnections between buildings on the same campus, or connections to cloud providers.

Copper (Ethernet)

CAT6 or CAT6A copper cables remain relevant for short-distance connections (up to 100 meters) and speeds of up to 10 Gbps. Their main advantage? Cost. Copper infrastructure is less expensive to deploy and maintain. However, the signal degrades more quickly with distance, and copper is sensitive to electromagnetic interference.

How does it work in practice?

Setting up a cross connect generally follows a standardized process.

1 Partner identification: You identify the partner or provider you want to interconnect with, whether it's a telecom operator, a cloud provider such as AWS or Azure, an internet exchange point (IX), or simply another data center customer.

2 Presence verification: You check that this partner is located in the same data center (or on the same campus). Carrier-neutral data centers generally host dozens or even hundreds of different operators and providers.

3 Order: You place your order with the data center manager, specifying the type of connection you want (fiber or copper), the endpoints (your rack details and those of your partner), and the target speed.

4 Installation: The data center technical teams pull the cable from your rack to the partner's rack, passing through cable trays and the Meet-Me Room if necessary.

5 Configuration: Once the cable is in place, you configure your network equipment to use the connection.

Delivery time: Generally, it takes between 24 hours and a few days, depending on the data centers. This is significantly faster than deploying a traditional carrier link.

Typical use cases

Cross-connects are not just for digital giants. Here are a few situations where they become virtually indispensable.

Direct connection to the cloud

The main cloud providers (AWS, Microsoft Azure, Google Cloud, OVHcloud, Scaleway) offer private connection services (AWS Direct Connect, Azure ExpressRoute, Google Cloud Interconnect). These dedicated links pass through cross connects established in partner data centers. As a result, your cloud workloads benefit from reduced latency, guaranteed bandwidth, and enhanced security compared to a traditional internet connection.

Multi-operator redundancy

No serious company relies on a single internet service provider. Cross connects allow simultaneous connection to multiple telecom operators in the data center. If one fails, traffic automatically switches to another. This redundancy, which is difficult and costly to implement via traditional connections, becomes trivial with cross connects.

Peering and exchange points

Internet exchange points (IX ou IXP) allow operators and companies to exchange traffic directly, without going through intermediaries. In France, France-IX in Paris and Lyon-IX offer this possibility. Connecting to them requires a cross-connect to the IX infrastructure, a simple operation when you are hosted in a data center that accommodates it.

B2B partnerships

Does your company work closely with a SaaS publisher, logistics provider, or financial partner? If both of your infrastructures are hosted in the same data center, a cross connect establishes a high-performance private link between you. Ideal for exchanging sensitive or large amounts of data.

What to check before ordering

A cross connect is not an impulse purchase. A few checks are necessary.

The presence of your partners: Ensure that the operator, cloud provider, or partner you are targeting is present in the data center. Carrier-neutral sites generally publish a list of their “residents.”

Port availability: On the supplier side, check that a port is available and compatible with the desired type of cross connect (fiber, Ethernet, etc.).

Recurring costs: AIn addition to installation costs, cross connects generate a monthly rental fee. Compare rates between data centers, as they vary significantly depending on the operator and location.

The ability to evolve: Anticipate your future needs. Upgrading from a 1G to a 10G cross connect is generally straightforward, but it's best to plan for an infrastructure capable of scaling up from the outset.

Start-up delays: Some data centers guarantee installation within 24 hours, others within several weeks. Factor this parameter into your project schedule.

Limits to be aware of

Cross-connect is not a universal solution. There are a few limitations worth mentioning.

Constraints to anticipate

• Geographical proximity: By definition, a cross connect links two points within the same data center (or campus). To interconnect two remote sites, you will need to use a telecom operator or a long-distance interconnection service (dark fiber, MPLS, etc.).
• Cable management: In a dense data center, the number of cross connects can quickly become difficult to manage. Rigorous documentation and careful labeling are essential to avoid chaos.
• Notice periods: Some contracts include minimum commitments or notice periods for termination. Read the terms and conditions before signing.

A strategic advantage for your infrastructure

Cross connect embodies a simple philosophy: why complicate what can be straightforward? By establishing private physical connections with your partners, operators, and cloud providers, you gain performance, security, and cost control.

For companies that operate colocation infrastructure, cross-connects are becoming a criterion for choosing a data center, just like Tier certification, PUE, and geographic location. A data center with extensive interconnections opens up possibilities that other, more isolated data centers cannot offer.

At Datalok, we know that connectivity often determines the success of a hosting project..

Our platform allows you to compare data centers based on their interconnection options: operators present, accessible exchange points, availability of cross connects, to identify the location that truly meets your needs. Because a well-connected infrastructure is a high-performing infrastructure.

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