CCNA Cisco Certified Network Associate Study Guide - FTP Server

510 Chapter 10 � Wide Area Networking Protocols
2. The ISDN switch uses the SS7 signaling technique to set up a path to
a remote switch.
3. The remote switch sets up the D-channel link to the remote router.
4. The B channels are then connected end-to-end.
Primary Rate Interface (PRI)
In North America and Japan, the ISDN Primary Rate Interface (PRI, also
known as 23B+D1) service delivers 23 64Kbps B channels and one 64Kbps
D channel for a total bit rate of up to 1.544Mbps.
In Europe, Australia, and other parts of the world, ISDN provides 30
64Kbps B channels and one 64Kbps D channel for a total bit rate of up to
2.048Mbps.
ISDN with Cisco Routers
Accessing ISDN with a Cisco router means that you will need to purchase
either a router with a built-in NT1 (U reference point) or an ISDN modem
(called a TA). If your router has a BRI interface, you’re ready to rock. Otherwise,
you can use one of your router’s serial interfaces if you can get ahold
of a TA. A router with a BRI interface is called a TE1 (terminal endpoint 1),
and one that requires a TA is called a TE2 (terminal endpoint 2).
ISDN supports virtually every upper-layer network protocol (IP, IPX,
AppleTalk, you name it), and you can choose PPP, HDLC, or LAPD as your
encapsulation protocol.
When configuring ISDN, you’ll need to know the type of switch that your service
provider is using. To see which switches your router will support, use the
isdn switch-type ? command in global configuration mode or interface configuration
mode. You need to do this because each manufacturer has a proprietary
protocol for signaling.
For each ISDN BRI interface, you need to specify the SPIDs that are using
the isdn spid1 and isdn spid2 interface subcommands. These are provided
by the ISDN provider and identify you on the switch, sort of like a telephone
number. However, some providers no longer require SPIDs to be
configured on the router. Check with your provider to be sure.