WAN PROTOCOLS

PPP:POINT TO POINT PROTOCOL HDLC:HIGH LEVEL DATA LINK CONTROL PROTOCOL FRAME-RELAY: HDLC: IS A PROTOCOL THAT IS USED FOR DATA ENCAPSULATION OVER THE SYNCHRONOUS SERIAL LINKS EXAMPLES:LEASED LINE CONNECTIONS ON ROUTERS. HDLC HAVE 2 TYPES: 1)STANDARD HDLC 2)CISCO HDLC STANDARD HDLC IS USED BY ANY ROUTER (OPEN STANDARD PROTOCOL FOR ENCAPSULATION) CISCO HDLC IS USED BY DEFAULT ON CISCO ROUTERS ON SERIAL LINKS. HDLC IS NOT A SECURE PROTOCOL ,BECAUSE IT NOT REQUIRED ANY AUTHENTICATION. BECAUSE LEASE LINES ARE DIRECT LINKS AND CONNECTED DIRECTLY,SO AUTHENTICATION IS NOT REQUIRED. CISCO HDLC IS MULTI-PROTOCOL SUPPORTED ,SO CAN ENCAPSULATE MULTIPLE PROTOCOL SIMULTANIOUSLY. WHILE STANDARD HDLC PROVIDES SINGLE ENCAPSULATIONS.. PPP(POINT TO POINT PROTOCOL): IS A ANOTHER METHOD FOR ENCAPSULATIONS OF DATA OVER EITHER DIAL-UP OR ISDN LINES. PPP IS A SECURE METHOD ,BECAUSE IT REQUIRED A AUTHENTICATION FOR CONNECTION . PPP IS USED 2 TYPES OF PROTOCOL 1:NCP(NETWORK CONTROL PROGRAM) 2:LCP(LINK CONTROL PROTOCOL) LCP IS CREATE THE LINK AND PROVIDES COMPRESSIONS FOR DATA AND NCP IS LOAD BALANCING THE LINE AND CONTROL THE FLOW OF DATA. PPP ALSO USED 2 TYPES OF AUTHENTICATION METHOD 1:PAP (PASSWORD AUTHENTICATION PROTOCOL) 2:CHAP (CHALLANGING HANDSHAKE AUTHENTICATION PROTOCOL) PAP: IS LESS SECURE PROTOCOL ,BECAUSE THE PASSWORDS ARE SENTS IN CLEAR TEXT FORMAT,WHILE CHAP: IS MORE SECURE THAN PAP , BECUASE PASSWORDS ARE ENCRYPTED AND THEN TRANSMIT. CHAP IS PRIODICALLY CHECKUPS PASSWORDS AND SEE WHO IS CONNECTED, SENDS A CHALLENGING STREAM TO CLIENTS WHO IS CONNECTED CALLED MD5(HASH VALUE) AND MATCH IT ,IF THE VALUE IS NOT MATCHED THE CONNECTION IS IMMEDIATLY TERMINATED.