About the CSX400CSX400 and CSX400-DC User’s Guide 13In half-duplex operation, the authenticator device challenges the peer device by generating aCHAP challenge, and the challenge contains an MD5 algorithm with a random number that hasyour encrypted password and system name. The peer device then applies a one-way hashalgorithm to the random number and returns this encrypted information along with the systemname in the CHAP response. The authenticator then runs the same algorithm and compares theresult with the expected value. This authentication method depends upon a password or secret,known only to both ends locally.Full-duplex operation places an additional step to the half-duplex operation that mirrors theoperation discussed above for a peer to validate the authenticator. The peer device challenges theauthenticator by generating a CHAP challenge, and the authenticator returns a CHAP response.The peer device challenges the authenticator device by generating a CHAP challenge, and thechallenge contains an MD5 algorithm with a random number that has your encrypted passwordand system name. The authenticator device then applies a one-way hash algorithm to the randomnumber and returns this encrypted information along with the system name in the CHAP response.The peer device then runs the same algorithm and compares the result with the expected value.This authentication method depends upon a password or secret, known only to both ends locally.LQMLink Quality Monitoring (LQM) is a link control mechanism used with PPP to determine whenand how often a link is dropping data in units of packets and octets. Link Quality Monitoringaccomplishes this by providing Link-Quality-Reports to determine if the quality of the link isadequate for operation. Link Quality Monitoring provides separate measurements for bothincoming and outgoing packets that are communicated to both ends of the link. The PPP LQMmechanism carefully defines the Link-Quality-Report packet formats, and specifies referencepoints for all data transmission and reception measurements. The LQM implementation maintainssuccessfully received packet and octet counts, and periodically transmits this information to itspeer using Link-Quality-Report packets.Multilink ProtocolMultilink Protocol (MP) is an extension of PPP that controls the way frames are transferred acrossseveral links whenever a single link is not sufficient to meet the requirements of your presenttraffic load. Multilink Protocol establishes several simultaneous links between two end points overswitched circuits (dial-up lines) in an ISDN network, and dynamically adjusts the bandwidthdemands between available links to maintain an effective data transfer.
