Optical Distribution Frame -ODF




Demand for high-speed communication, in-home, commerce, business, industry continues to grow with no signs of slowing down. It is now commonplace to have fibre connection directly to FTTX – Home, commerce, Business, industry, Mobile networks, Masts etc.

So we now have a significant amount of optical cables running underground across poles connecting POP/ Data Centre’s/ Distribution Centre’s / Street cabinets / Comms Cabinets. The deployment of fibre networks continues as demand for volume, and speed continues to grow. All of the fibre that converges in any of these locations has to be managed. This is achieved with an ODF – Optical Distribution Frame.

It is imperative to understand what you want from your ODF, which means understand current demands and typical expansion for the future. There is significant variation in the shape, size, fibre handling capability, internal-external, no of cables to be managed etc. We need flexibility expandability and a cost-effective solution.

Selecting the right ODF for a particular application is fundamental to well organised, cost-effective cable management.

Explanation of an ODF

An Optical Distribution Frame can take many shapes, sizes and specifications to cope with the increasingly varied demands from all of the various market sectors providing Optical Connectivity.

An ODF is a meeting point where you have incoming and outgoing cables. We may have Splice to Splice or Splice to Patch, either way. The ODF is a host to facilitate interconnections. The ODF will house splice trays / Adaptors for connectivity purposes.

It is important to understand your PON's demands and specify the ODF appropriately this will ensure cost-effective management of cables now and in the future.

Types of ODF 

The ODF construction will vary depending on specification and demands. This will take into account current and future requirements, location internal/external large or small. But there are 3 basic constructions which we will provide a solution to most requirements as detail in the table below.


Wall Mounted (Fig 2) 

These typically are for small-medium environments could be an office complex small industrial MDU-Multi Dwelling Unit. Typically managing anything from 12 fibre to 288 fibres as an indicator. They are generally of simple construction with fibre trays to house and manage fibre. Cable management and routing are limited given the size of the enclosure.

19" Rack Mounted (Fig 3)

This is typically for a medium-large entity where they have a comms room/closet and 19" racking systems to house the networking equipment. This is typically a very modular approach with expandability, where demand initially is small, but additional capacity can easily be added. A basic solution could be a 1U shelf 1-24 connections. Alternatively, it could be a dedicated 42U rack, to splice and Patch, managing 1296 connection.

Floor Standing (Fig 4)

This can take several forms, dedicated ODF in a POP or Comms room managing many thousands of interconnects. Or and external street cabinet managing customer/client connection. These are designed to manage volume providing Splice to Splice or Spice to Connectorisation to facilitating cross-connects.

Choosing the right ODF

It is important to have the network engineer, planner and operations fully engaged in the selection of the ODF. Many factors need to be considered to include but not exhaustive - Location, Space, Legacy, Current demand, Future Demand, Connectivity type, Cable management, Access, High Density. There may be a need for customisation.
Whichever unit is deployed, it must have easy access and the ability to maintain and manage moves changes and maintenance. This is where cable and fibre management is crucial.

Expandability is important, and it is possible to have modular cassettes which plugin and integrate with existing management. These units can be 12 fibre or 432 fibre.

Flexibility to have a splice to splice or splice to connectorisation, various adaptors to house the appropriate connectivity ST /FC/LC/MU/MTRJ/E2000 etc.

High Density where small form-fit connectorisation is used, commonplace in Data Centre’s. Management of fibre in these situations is challenging, and consideration must be given to the fibre management and connector extraction. 
Quality of service is paramount in a PON; therefore, only quality equipment should be installed by qualified engineers. Splice joints and connectorisation are sensitive to stress/tension any changes in the operational state of the PON could affect the entire network and its stability and reliability. Therefore it is imperative to have well-designed equipment able to supply Quality of Service.


The ODF is an essential part of your PON-Passive Optical Network. It is an asset that needs to be carefully selected and installed. Maintenance of this unit must be maintained at the highest level to ensure network stability and reliability, which is a minimum expectation of all telecom operators. Time spent understanding the current demands and future challenges will be time well spent when selecting your ODF, which will serve your organisation for many years.

CMW distribute a wide range of optical fibre products. Speak to the team to discuss your requirements and to get help with choosing the right product for your installation.