What is MDF Jumpering?

When you order a new internet connection, your internet service provider (ISP) will connect their service from the telephone exchange via a street cable to the Main Distribution Frame (MDF) of your apartment complex. This is called the ‘A’ side, which is owned by the ISP. In layman’s terms, the MDF is the box where all the phone and internet lines meet and come in from the street, and then branch off to the various units in the complex. The MDF is the point where the ISP owned services end and the tenancy owned services begin. The tenancy side is referred to as the ‘B’ side. The wires from the street terminate on one side of the MDF (the A side) and the wires to your unit are terminated on the other side (the B side). A jumper-wire is run between a pair of wires that is carrying your signal on the A side to the ‘pair’ that is connected to your unit on the B side. When issuing an invoice, we often refer to your service being jumpered from vertical A pair XX to vertical B pair XX. In larger apartment complexes, the A or B references may be another letter such as C, F etc.

For larger apartment or business building with numerous floors, there may be other Intermediate Distribution Frames (IDP) and sometimes a Final Distribution Point (FDP) that your service needs to be jumpered through before it reaches your unit.

Why do I have to pay for a new jumpering connection when the previous tenant had internet?

This is a common question we are asked. In most cases, when your ISP technician connects your new internet service to the MDF, they will install it to a new point on the frame, instead of the existing point where the previous tenant had their internet connection. This is common practice and there a couple of reasons why they do this;

First and foremost, the existing connection is left intact in case the new tenant requests to take over the previous tenants phone service. This then only requires a change of billing name for the service at the Telstra end.

Secondly, so they don’t disconnect another tenant’s services. If the service is connected to a pair on the frame which is not in use, the technician is guaranteed of not accidentally disconnecting someone else’s services by mistake.

Typical small modern MDF.