Below is a diagram displaying the basics of a SIP network. Showing you how it relates to your local area network (LAN) and in house hardware. SIP Phones and devices are usually powered using POE (Power Over Ethernet). This can be provided either from your POE enable network switch (LAN), or by using a separate power supply (this is not included with most SIP phones).
NB. Please ensure you have checked your network for POE or need for a power supply in your LAN.