Cabletron Systems Cabletron CyberSWITCH CSX5500 User Manual

Also see for CyberSWITCH 5500: Quick start Manual

Contents

USER’S GUIDE192 CyberSWITCH• IP Host (RFC 1294)RFC 1294 provides a simple security exchange at connection time, along with an encapsulationmethod for IP datagrams.BASE DATA RATEOnly used for Dial-Out. This value represents the throughput on a B-channel or pre-ISDN linkconnecting the CyberSWITCH to a device. The data rate can be specified as either 56,000 or 64,000bps. The default configuration for the base data rate is 64,000 bps. If 64,000-bps connections to thedevice are not possible, this value should be set at 56,000 bps.INITIAL DATA RATEOnly used for Dial-Out. The initial data rate determines the bandwidth that will be attempted whenopening the first wide area connection. This provides you with a mechanism to request that a groupof parallel connections be made to a remote device rather than a single connection. This will allowdata to begin to flow at greater rates without waiting for the Throughput Monitor to detect anoverload condition. Calls will be made until an additional call would exceed the configured value.The value is configured as a number from 2,400 to 1,024,000. For example, if you have configuredthe Base Data Rate at 64 Kbps, and the Initial Data Rate at 256,000, the system would attempt toinitially use four calls (connections) running in parallel (256,000 / 64,000 = 4). The defaultconfiguration for the Initial Data Rate is 64,000 bps.MAXIMUM DATA RATEThe Maximum Data Rate is used to limit the total number of channels that can be committed to asingle device (logical connection). This sets an upper boundary for line and capacity utilization.This upper boundary allows you to keep one remote device from crowding out other devices andusing an unfair share of available resources. This parameter is enforced on inbound and outboundcalls. The system will not accept or make a call when the added bandwidth will exceed theconfigured maximum. The value is configured as a number from 2,400 bps to 3,072,000 bps. Youmay configure any value in this range. For example, if you have configured the base data rate at64,000 bps, and the maximum data rate at 512,000 bps, the system would use a maximum of eightcalls (connections) running in parallel to open up bandwidth (512,000 / 64,000 = 8). The value neednot be a multiple of the Base Data Rate. The default configuration for the maximum data rate is128,000 bps.Note: A condition may occur in which the number of connections has reached the point wherethe maximum data rate will be exceeded with the next additional connection, and yet theremote device may initiate another call to the system. This inbound call causes themaximum data rate to be exceeded and the system will drop a connection. If the remotedevice is auto-dialing, this flip-flop condition will continue until you manually correct theproblem. To correct this problem, configure the Throughput Monitor information to beidentical on the CyberSWITCH and the remote device, or disable Throughput Monitoringon one of the devices. The Internet Engineering Task Force (IETF) is working on a standardsolution to this problem.If you are using multiple connections running in parallel (i.e., to the same device), themaximum number of connections that can be aggregated is 32. For maximum performance,however, we recommend aggregating no more than eight connections at a time.