Have file sharing become a problem across town with your branch offices? With ever-rising budgets for leased lines, but video calls that are still getting stuck between your city locations? It’s not the smallest bug in the world. You’re using the wrong network layer to solve the problem.

An IP MAN addresses this very issue. It connects all of the offices, campuses, or data centers within a single city to a single high-speed IP-based backbone that joins them together. Then you can cut the cost of using multiple point-to-point connections and deploy a single network to cover your entire metro region.

This guide explains what an ip metropolitan area network is, how it operates, and why it’s superior to slower options for organisations located throughout a city.

What Is an IP Metropolitan Area Network?

IP metropolitan area network: a network that consists of a collection of local area networks (LANs) that span a metropolitan area and route all packets through Internet Protocol. Imagine three offices throughout the town. They are powered with their own LAN. An IP MAN connects those three LANs, allowing staff in any building to access the same files, apps, and servers at top speed.

A difference in size is what distinguishes the MAN from its neighbours. A LAN is confined to a single building. A wide area network (WAN) is a network that covers a large geographical area, such as across countries. A MAN is positioned between, typically 5–50 kilometers, so it’s a city, a university put on several sites, or a group of hospitals having clinics spread out around town.

This ‘IP’ component is as significant as this ‘metropolitan’ component. Older metro networks failed to communicate directly with the internet and operated their own transport protocols. The IP MAN avoids that translation step. Your traffic knows the language of the Internet, so it’s one less hop to connect to cloud platforms, remote offices, or the public Web.

Why Businesses Feel the Pain Without One

Not many companies actively search for an IP MAN. With the same wall to slam, they find themselves in the need of one.

• Slow file transfers between offices (seconds instead of minutes).
• The stuttering video calls and shared apps aren’t working beyond the first site.
• Increasing costs due to each office being leased to headquarters using individual lines.
• IT staff going from one location to another and using multiple tools and rules.Multiple rules and tools at each location keeping it from being centralized.
• When growth plans are stalling because of the need for a new branch you have to start fresh and create a new brand.

These are not individual issues. All are caused by a single issue: your organization has reached the limits of a LAN, yet hasn’t reached the global scope of a WAN. An IP MAN is the perfect fit for that space.

How Does an IP Metropolitan Area Network Work?

All LANs are connected by an IP MAN to a common fiber backbone and then traffic is directed between the LANs via IP addressing. This is the trajectory of the data as it is transported:

1. A device pushes out data over its LAN, like any other office LAN.
2. The edge router of the LAN passes that traffic on to the metro backbone.
3. The traffic is carried on fiber cable across the city, and is often laid out as a ring, with no single line destroying the network.
4. Routers encountered on the way read the IP address and forward the packet to the appropriate destination site.
5. The data is received by the destination LAN and sent to the target device.

It’s like an urban transit system. These are the bus stops in each building. The backbone of the metro is the principal road that ties all the stops together. Buses (your data packets) follow IP addresses, just like passengers follow route numbers, and both always arrive at the right stop, without getting in each other’s way.

What Powers the Backbone

There are several transport technologies that can be used to carry IP traffic across a metro network, and most organizations are using more than one of these technologies:

• The most popular – and affordable, familiar to IT teams and easy to scale as you add sites – is Metro Ethernet.
• IP/MPLS – labels traffic to ensure it follows a predictable path, something service providers need to offer consistent service.
• Dark fiber – fiber strands that are not currently being used by the organization, can be used when you want to have 100% ownership and control of the line.
• DWDM (dense wavelength-division multiplexing) – packs multiple data channels into a single fiber, without the need for additional cable.

A regional bank could use Metro Ethernet to connect 30 branches. A city government could use a provider-provisioned IP/MPLS service on top of the dark fiber to enable the connection between all public buildings in the city. Both configurations are considered to be an IP MAN, but they’re simply sized according to your needs.

IP MAN vs. LAN vs. WAN

Factor	LAN	IP MAN	WAN
Coverage	One building	A city (5–50 km)	Countries or continents
Typical speed	100 Mbps–10 Gbps	1 Gbps–100 Gbps	Varies, often slower per link
Backbone	Ethernet, Wi-Fi	Fiber, Metro Ethernet	MPLS, leased lines, satellite
Ownership	Single company	One company or shared with a carrier	Usually leased from carriers
Best for	A single office	Multi-site organizations in one city	National or global operations

A WAN-level reach with a WAN-level cost and delay, is provided by an IP MAN if your offices are located in one city. Once you enter another country you truly do need a WAN. Most companies go straight to a WAN when an IP MAN would have done the job with less expenses and complexity.

Real Benefits You Can Measure

• Improved inter-site transfers. With speeds of 1Gbps and higher, there is no lag to stop productivity while sharing a file or during video calls.
• Lower long-term cost. If there is one shared backbone, it is almost always the cheaper choice in the long term than multiple leased WAN circuits.
• Centralized IT management. You manage, secure and update all sites from a centralized console rather than separate systems.
• Easy growth. When a new office is added, the typical scenario is not to create a new network, but to make connections to a backbone network.
• Shared resources. All sites can access the same servers, storage and applications, without having to duplicate hardware at each site. 

Challenges to Plan For

If you’re not aware of the trade-offs when you’re designing an IP MAN, you could end up with unexpected expenses down the road:

• Upfront cost. It is more expensive to deploy fiber and install routers throughout a city than to wire one office.
• Security surface. The more connected the sites are the more entry points there are and so the firewall and monitoring should be across the network and not just at the headquarters.
• Skilled staff required. It is more difficult to run a city-wide network than to run a single LAN.
• Congestion risk. If traffic is not managed properly, many sites have peak hour traffic that can slow the entire backbone.

All of these do not preclude an IP MAN. It’s just that you should build security and capacity in from the beginning, rather than stacking them on in the back.

Where IP MANs Are Used Today

• Universities link multiple campuses — providing the same portals and systems for students and staff across the city.
• Patient records, lab results and imaging can be instantly shared between hospitals, impacting patient care.
• City governments connect police stations, transport offices and public services for better coordination.
• Internet and cable companies rely on the IP MANs as the backbone to deliver broadband and TV services to a whole city from a single location.

Conclusion

The idea behind an IP metropolitan area network is to provide organizations located throughout a metropolitan area with the speed and shared access that a single LAN cannot provide, but at the cost and complexity of a full WAN. If you’re tired of slow transfers, higher leased-line bills, or disconnected IT systems when you’re in one metro area but looking to move to another in the same metro area, an IP MAN is sure to help.

Match the network to the real distance to be covered. If the IP MAN stays within one city, then his cost will be retrieved fast. Enter a different country, and it’s time to consider using a WAN. 

Frequently Asked Questions