A boundary node router determines whether a received packet includes a SIP message and a REGISTER message, and, if so, adds its router identifier to a REGISTER message which includes a user identifier and a user terminal identifier, sent from a user terminal, and sends the message to a SIP server. In one configuration, the pole-mounted upper reader module includes a one-piece post housing section mounted to the main housing structure and extending therefrom and containing imaging electronics and optics of the upper reader. The imaging can be performed utilizing low-energy beam techniques such as scanning electron microscopy; however, more sophisticated imaging techniques can also be employed. The holes are coated with a protective coating, such as a silicon carbide coating, by chemical vapor deposition, including chemical vapor deposition at atmospheric pressure.