Polycom PRI / T1 - ISDN terminal adapter - ISDN Product Details
QBRI, PRI or Serial/V.35 network interfaces can be added to support your specific network environment in place of or in addition to the IP network connectivity. And the additional network module plugs straight into the HDX codec - truly convenient and integrator friendly. This integrated solution eliminates the need for external hardware bricks and maintains the thin, clean profile of the 1U rack-mount form factor. To install, remove the blank faceplate from the back of the codec (remove two screws), then insert the network card and tighten the two attached screws.