The DTE port on the back of an IP Office Control Unit is not normally used when configuring an IP Office system. However the DTE port can be used to erase the system’s operational software and/or configuration if necessary.
Due to the drastic nature of these actions they should only be performed if absolutely necessary to return a system back to working order. In either case you must ensure that you have a backup copy of the system configuration.
Access to the DTE port requires a serial cable between your PC/Laptop and the IP Office (such as a standard modem cable).