ISDN

ISDN:
ISDN has the following characteristics:
• Works at the Physical, Data Link, and Network Layers.
• Often used in backup DDR Dial on Demand Routing.
• Makes use of existing telephone.
• Supports simultaneous data and voice.
• Max speed at 125 Kbps with PPP Multilink.
• Call setup and data transfer is faster than typical modems.
• BRI has 2 x 64 1Kbps B Channels for data and one 16 Kbps D Channel for control
• PRI has 23 x B Channels and one D Channel in the US, or 30 x B Channel and one D Channel in Europe.
• E protocol specifies ISDN on existing telephone network
• I protocol specifies Concepts, terminology, and Services
• Q protocol specifies switching and signaling
• ISDN Reference Points include R(between non ISDN equipment and TA), S(between user terminals and NT2), T(between NTI and NT2 devices) and U(between NTI devices and Line Termination Equipment in North America)
• router always connected by the U interface into NT1
• BRI interface is considered Terminal Equipment type 1 TE1
• TE1 is built into the ISDN standards
• Needs to have Terminal Adapter TA to use TE2