IPNext 190 System Installation GuideAddPac Technology Proprietary & Documentation 132 - 120Pinout of UTP Cable (RJ-45 to RJ-45)The RJ-45 to RJ-45 Ethernet cable is used to connect the Ipnext190 with another device(typically hub). The sequence of the RJ-45 connector pins is shown in below figure. For thesignals between the IPNext190 with another device and pinout specification, refer to Figure 4-1,“Signals and Pinout of Serial Ethernet Cable”.Figure 5-1 100Base-TX RJ-45 ConnectorTable 5-2 Signals and Pinout of Serial Ethernet CableRJ-45 Signal Direction RJ-45 Pin1 Tx + → 12 Tx - → 23 Rx + ← 34 - - 45 - - 56 Rx - ← 67 - - 78 - - 81. The table above shows the specification of serial cables that connect theIPNext190 with the hub.2. If you want to connect an IP-PBX with another IP-PBX or the gateway with thePC, you should use cross cables.