PRI

For PRI^6.4 lines (E1 in Europe or T1 at USA) there are telephony cards with 1, 2 or 4 ports. At Figure 6.7 a PRI card is showed with 2 ports. Depending of the card manufacturer, port 1 can be designated as 1 (Digium) or A (Sangoma), and port 2 as 2 or B.

Figure 6.7: PRI card

Leds

• Fixed Red: With link;
• Fixed Green: Without link.

Pinout

The correct cable pinout between PSTN, IPBbrick.GT and PBX can be seen at Figure 6.8.

Figure 6.8: Crossover RJ-45 cable pinout between IPBbrick.GT and PBX

The connection between the PRI modem and the existant PBX can use:

• Coaxial cables: Two coaxial cables (send and receive) are connected between the PRI modem and the PBX (Figure 6.10). The connector is usually BNC but different types of BNC connectors are used, depending of the operator.
• UTP cables: One PRI UTP cable connected between the PRI modem and the PBX using RJ-45 connectors (Figure 6.11)

Depending of that connection type, IPBrick can intercept that PBX/PSTN connection using:

• balun (Figure 6.9) is a converter that can be plugged into by 2 coaxial cables at one side (2 BNC's), and at the other side a single RJ-45 cable can plug into an IPBrick telephony card port. The connection schema can be viewed at Figure 6.13;
• RJ-45: The connection between PBX, IPBbrick.GT and PSTN is made by UTP cables using RJ-45 connectors (Figure 6.12);

Figure 6.9: BNC/RJ45 Balun

Figure 6.10: PRI modem and PBX connection by coaxial

Figure 6.11: PRI modem and PBX connection by UTP

Figure 6.12: IPBrick intercepting PRI line and PBX using UTP cables only

Figure 6.13: IPBrick intercepting PRI line and PBX using baluns

NOTE: For BRI/PRI straight connections using UDP, normal ethernet network cables can be used (4 pairs). No need to use specific BRI/PRI UDP cables (2 pairs).

Footnotes

... PRI^6.4

Primary Rate Interface