Copper Backbone

Introduction

Until recently TeleCAD-GIS did not allow two exchanges to be connected by copper cables in any way. It reported errors in network topology (e.g. When you run the command Network Tree).

In 2013, support for copper backbone was added, allowing entry of the backbone cable, mixed cable (with twisted pairs from access and backbone network), definition of backbone from DT to DT and connection with TIS backbone (similar to the access network).

Terminology:

Backbone is a set of cables, from one to another DT interconnected with splice points. It can include mixed cables and backbone cables. (For TeleCAD-GIS, backbone elements are both splice points and exchanges.)

Backbone Cable is a cable that belongs exclusively to the backbone (one or more) and does not belong to any access cable. Twisted pairs of these cables are used exclusively for directly connecting exchanges.

Mixed Cable is a cable that belongs to one access network and one or more backbones. Part of these cables’ twisted pairs is used to interconnect the exchanges, and a part is used for connecting exchange (to which the cable belongs) to end users.
(Note: in the drawing, mixed cables are displayed exactly in the same way as the access network cables (in pink). On the other hand, when you mark a certain backbone in the backbones list, in the cables list these cables will be displayed in black, as opposed to the backbone cables which are displayed in green.)

Access network cable, as its name implies, does not belong to any backbone.
(Note: in the drawing, the access network cables are displayed in the standard manner (in pink). (Same as the mixed cables.)

Figure 1

Purpose

If there is a network in the drawing with two exchanges (or more) connected with copper cables, the program cannot automatically determine which part of the network belongs to one exchange and which one to the other. To enable this, the user has to define a demarcation point.

For this purpose, we use the backbone cable.
Backbone cables are those cables that do not belong to any access network serving area.

In reality, the backbone function is to conduct the twisted pairs connecting the two exchanges, while from the viewpoint of TeleCAD-GIS it has an additional role: to distinguish the two networks. When you define a backbone cable, TeleCAD-GIS easily creates the network topology as it is now quite clear which part of the network belongs to one exchange and which one to the other. If you then look at the Network Tree you will see two clearly defined branches that start from the exchanges.

Examples

To illustrate, here are two examples that differ only in the positions of the backbone cable within the network.

In the first case, TeleCAD-GIS will, when assembling the topology, assign only one DT to  RSS Exchange 1, and the other two will belong to MSAN Exchange 2 (Figure 2).
(This is clearly visible in the Network Tree.)

Figure 2

In the second case, by choosing different position of the backbone cable, TeleCAD-GIS assigns two DTs to RSS Exchange 1, and the remaining DT is assigned to MSAN Exchange 2 (Figure 3).
(This is also verifiable using the Network Tree.)

Figure 3

It is clear, therefore, that the choice of the backbone cable position in the network is crucial for the proper demarcation.

Commands

In working with copper-built backbone we use the following commands:

• Backbone Cable - (drawing a new backbone cable)
• Backbone -> Distribution network - (conversion of backbone cable to access network distribution cable)
• Distribution network -> Backbone - (conversion  of access network distribution cable to backbone cable)
• Define Backbone - (opens a window containing a number of tools that define and regulate the copper-built backbone)