8.1.7 Network DevicesYou must evaluate the network devices that are used in the existing network to see if a VoIP network can beimplemented. Below are the points that should be evaluated.Can the firewall pass packets appropriately?If the VoIP network contains a firewall, the firewall must be configured appropriately to allow VoIP packets topass through the network without being blocked by filtering. For details about the protocols and port numbersthat the PBX uses for VoIP communication, refer to "8.5 Port Security".The ports for which you need to configure the firewall may vary depending on the network conditions.For more information, consult your network administrator.Are layer 2 or higher switches used?Use of repeater hubs can increase the network load, and therefore may result in degradation in speech quality.To ensure high speech quality, use only layer 2 or higher switches. Use of layer 2 or higher switches is alsostrongly recommended for connecting IP telephones.NoteNote that the port of the switching hub that connects to the mother board should be set to operate under"Auto Negotiation" mode.Does all equipment on the LAN support 1000BASE-T connection?To use the Gigabit Ethernet feature for the LAN, all equipment on the LAN must support 1000BASE-T. Formore information, consult your network administrator.Are Category 5 (CAT 5) or higher cables used for 10BASE-T/100BASE-TX?When connecting network devices, make sure to use CAT 5 or higher cables for 10BASE-T/100BASE-TXconnection. If other types of cables are used, communication may not be carried out normally.Are Enhanced Category 5 (CAT 5e) or higher cables used for 1000BASE-T?When connecting network devices, make sure to use CAT 5e or higher cables for 1000BASE-T. If other typesof cables are used, communication may not be carried out normally.316 Installation Manual8.1.7 Network Devices
