Cabletron Systems Cabletron CyberSWITCH CSX5500 User Manual

Also see for CyberSWITCH 5500: Quick start Manual

Contents

Central Site Remote Access Switch 259CONFIGURING A LTERNATE ACCESSESFrame Relay Accessesnetwork, the one to which the access line is directly connected, routes the packet to the intendeddestination based on the DLCI therein. Hence, each packet is routed independently through thenetwork based on the addressing information provided by this identifier.PVC L INE P ROTOCOLThe PVC line protocol determines which type of data encapsulation will be used on the PVC. Theoptions are PPP Point to Point Protocol or FR_IETF. PPP allows PPP authentication for theassociated device. FR_IETF is a multiprotocol encapsulation for Frame Relay, currently specifiedby RFC 1490. FR_IETF protocols include IP, MAC Layer Bridge, IPX, and AppleTalk. The defaultPVC line protocol is PPP.PVC N AMEThe PVC name associates the PVC with a device table entry, whether it is defined in an on-node oroff-node database. The PVC name must match the device name for both on-node and off-nodedatabases. However, if a virtual circuit has been configured with PPP as the line protocol, and theassociated on-node device entry has enabled outbound authentication, then the names are notrequired to match.COMMITTED I NFORMATION R ATE ( IN K BITS/ SECOND )A frame relay circuit has two transmission rates associated with it: the Committed Information Rate(CIR) and an Excess Information Rate (EIR). The committed information rate is the bandwidthrequested for a PVC at service subscription time. This parameter should be available from theservice provider at subscription time. Even if you do not wish to pay extra for a CIR from yourcarrier, we recommend configuring CIR where the following is true:physical speed/number of PVCs = CIRThis configuration allows quick alleviation of congestion. For a more in-depth explanation of theCommitted Information Rate, refer to the Data Rate Control Overview.EXCESS INFORMATION RATE (IN K BITS / SECOND )The Excess Information Rate is the bandwidth available above and beyond the committed rate. Theframe relay software has the capability to transmit data above the committed information rate upto the excess information rate. This parameter should be available from the service provider atsubscription time. For a more in-depth explanation of the Excess Information Rate, refer to DataRate Control Overview.ENABLE/D ISABLE C ONGESTION C ONTROLCongestion Control can be enabled or disabled. This parameter should only be disabled for captivenetworks or those users very familiar with the Frame Relay Service. For a more in-depthCongestion Control explanation, refer to Congestion Control Overview.R ATE M EASUREMENT INTERVAL (I N M SECS )The Rate Measurement Interval in combination with the current transmit or receive rate is used todetermine the number of bytes that can be handled in a single rate monitoring period on a givenPVC. This parameter should only be changed for those users very familiar with the Frame RelayService. For a more in-depth explanation, refer to Data Rate Control Overview.