摘要 |
A combination LAN and PBX system utilizes the unassigned pair of wires in Category-5 cable to provide a "parallel network" for a PBX over existing ETHERNET cable. The PBX network is unaffected by ETHERNET traffic even though it is carried via the same cable. The apparatus includes a PBX hub and a plurality of phone modules. The PBX hub couples to the customer's ETHERNET hub and has a plurality of slots for receiving "gateway modules". The gateway modules include modules for coupling the PBX hub to POTS lines, T1 lines, xDSL modems, cable modems, etc. Each phone module has two RJ-45 jacks and an RJ-11 jack. The RJ-45 jacks enable the phone module to be coupled to an ETHERNET LAN at a point where some other device is coupled to the LAN without interrupting the connection of the other device. The RJ-11 jack couples an ordinary single line phone (via the red and green conductors of the RJ-11 jack) to the undefined pair of the Category-5 cable. According to a preferred embodiment, the phone modules include a circuit for detecting a failure of the parallel network (e.g. a power failure) and for automatically coupling the single line phone to the POTS line carried by the Category-5 wire. Traffic on the PBX network is packetized in frames which have a variable payload length and one or more fields for maintaining QOS. |