Installation and Administration Guide 19March 2000 Remote Office 9150 descriptionConnection optionsIntroductionCommunications between the Remote Office 9150 unit in your office and thehost PBX take place using 10BaseT Ethernet or ISDN BRI connections, or both.This section provides a description of each of these connections.10BaseT Ethernet interfaceVoice over IP technology is used to carry voice conversation and phonesetcontrol signals over your IP network to the host PBX. The voice data isforwarded as UDP/IP packets, and the signaling data is forwarded as TCP/IPpackets.ISDN BRI lines to PSTNThe PSTN provides a cost-effective alternative to leased lines. You can useISDN BRI lines at the Remote Office 9150 site to make local calls withoutinvolving the host PBX. You can also choose to use the ISDN BRI lines insteadof the IP network to route calls through the host PBX.To use ISDN BRI lines, you must install trunk interface modules. The RemoteOffice 9150 unit can support up to four U or S/T ISDN BRI trunk interfacemodules. (See “Add-on modules description” on page 17.)Quality of Service transitioning technologyIf both the IP network and ISDN BRI lines are used, you can use the QoStransitioning technology to reroute calls from the IP network to the circuit-switched network when the QoS on the IP network degrades. When the QoSreturns to normal, the QoS transitioning technology automatically moves thecalls back to the IP network.The Remote Office 9150 unit monitors the QoS on the IP network. If the QoSfalls below preprogrammed acceptable thresholds, calls are dynamically andtransparently switched to the ISDN BRI lines. See “Quality of Servicetransitioning technology” on page 45 for additional details.
