# Overview of network connections

The CG 6565E board has two Ethernet connectors and optional T1/E1 trunk connectors. The T1/E1 connectors are available in configurations up to eight trunks. Each configuration uses a rear I/O board to connect to PSTN and Ethernet networks.

This section provides the following information:

- An illustration of the board variants.

- A description of how to connect the CG 6565E board variants to a PSTN or Ethernet network.

Warning: | Important safety notes for telephony connections Allow only qualified technical personnel to install this board and its associated telephone wiring. Make sure the PC chassis is grounded through the power cord or by other means before connecting the telephone line. If your system requires an external power supply, make sure it is grounded through the power cord or by other means. Never install telephone wiring during a lightning storm. Never install telephone jacks in wet locations. Telephone companies provide primary lightning protection for their telephone lines. However, if a site connects to private lines that leave the building, make sure that external protection is provided.