1	Interconnecting Cisco Networking Devices Module 9 WAN / ISDN
2	Overview WAN Terms and Connection Types Frame Relay ISDN
3	WAN Terms Customer Premises Equipment (CPE) Demarcation Point (Demarc) Local Loop Central Office (CO) Toll Network
4	WAN Connection Types Leased Lines Dedicated line Circuit Switching Dialup modems / ISDN Packet Switching Frame Relay
5	High Level Data-Link Control (HDLC) Every vendor has a proprietary version. Default Encapsulation for Cisco Routers
6	Point-to-Point Protocol (PPP) Open standard Provides authentication Uses Link Control Protocol (LCP) to build and maintain the connection
7	Link Control Protocol (LCP) Options Authentication Compression Error Detection Multilink PPP Callback
8	PPP Session Establishment Link-Establishment Phase Authentication Phase Network Layer Protocol Phase
9	PPP Authentication Password Authentication Protocol (PAP) Passwords in clear text Only asks once for password Challenge Handshake Authentication Protocol (CHAP) Challenge request sent from remote router One way MD5 hash sent back Periodically asks for authentication again.
10	Frame Relay Has its roots in X.25 technology Leaves out error checking from X.25 Packet-switched technology Includes a Committed Information Rate (CIR)
11	Committed Information Rate (CIR) Two separate bandwidth specs for Frame Relay Access Rate Max speed at which Frame Relay can transmit CIR The max guaranteed speed that will be delivered
12	Frame Relay Encapsulation Two types of Encapsulation Cisco (default and proprietary) ietf (RFC 1490 standard) Cisco Router(config)# int s0 Router(config-if)# encapsulation frame-relay IETF Router(config)# int s0 Router(config-if)# encapsulation frame-relay ietf
13	Frame Relay Virtual Circuits Two types of Virtual Circuits Permanent Virtual Circuits (PVC) Most popular Switched Virtual Circuits (SVC) Like a phone call
14	Data Link Connection Identifiers (DLCI) Frame Relay PVCs are identified to end devices using DLCIs. Locally significant #s start at 16 Router (config)# int s0 Router (config-if)# frame-relay interface-dlci 16
15	Local Management Interface (LMI) Signaling standard used between your router and the first Frame Relay switch you’re connected to Keepalives Multicasting Global Addressing Status of Virtual Circuits
16	LMI (Cont.) By default, LMI is set to auto-sense Three types of LMI Messages Formats Cisco ANSI Q.933A Router(config)# int s0 Router(config-if)# frame-relay lmi-type ? cisco ansi q933a
17	Frame Relay Congestion Control Because CIR is important, congestion bits were defined to determine which packets can be dropped Discard Eligibility (DE) Forward Explicit Congestion Notification (FECN) Backward Explicit Congestion Notification (BECN)
18	Implementation and Monitoring Configuring Frame-Relay Router(config)# int s0 Router(config-if)# encapsulation frame-relay Router(config-if)# ip address 172.16.20.1 255.255.255.0 Router(config-if)# frame-relay lmi-type ansi Router(config-if)# frame-relay interface-dlci 101 Subinterfaces Router(config-if)# encapsulation frame-relay Router(config-if)# int s0.16 ? multipoint – Treat as multipoint link point-to-point – Treat as point-to-point link
19	Integrated Services Digital Network (ISDN) Designed to transport voice, video, and data Can be used as a backup to leased lines Call setup is quicker than analog modems PPP is the most common encapsulation across ISDN connections
20	ISDN Connections Basic Rate Interface (BRI) Primary Rate Interface (PRI) B = Bearer Channel for actual data D = Data Channel for signaling and call setup
21	ISDN Terminals
22	ISDN Reference Points
23	ISDN Protocols Protocols starting w/ E deals w/ “existing” network Protocols beginning w/ I deal w/ “concepts, aspects and services” Protocols beginning w/ Q deal w/ switching and signaling Q.921 Q.931 etc
24	ISDN Switch Types isdn switch-type The provider will provide which type basic-5ess basic-dms1000 basic-ni1 primary-4ess etc
25	ISDN w/ Cisco Routers Router(config)# isdn switch-type basic-ni Router(config)# int bri0 Router(config-if)# encap ppp (optional) Router(config-if)# isdn spid1 086506610100 8650661 Router(config-if)# isdn spid2 086506620100 8650662 If you’re not using Dial-on-Demand, you need to configure these Router(config)# isdn switch-type basic-ni Router(config)# isdn dialer map ip address name name connection number Router(config-if)# ip address address mask
26	Dial-on-Demand Routing (DDR) Used to allow two or more Cisco routers to dial an ISDN connection on an “as-needed” basis. The route is determined to be across the dial-up connection “Interesting packets” dictate a DDR call Dialer information is looked up and the call is placed Traffic is transmitted Call is terminated when no more interesting traffic is seen, and the idle-timeout period expires
27	Configuring DDR Create Static Routes Router(config)# ip route 172.16.50.0 255.255.255.0 172.16.60.2 Router(config)# ip route 172.16.60.2 255.255.255.255 bri0 Specify “Interesting Traffic” Router(config)# dialer-list 1 protocol ip permit Router(config)# int bri0 Router(config-if)# dialer-group 1 Configure the Dialer information Router(config-if)# ip address 172.16.60.1 255.255.255.0 Router(config-if)# no shut Router(config-if)# encapsulation ppp Router(config-if)# dialer-group 1 Router(config-if)# dialer string 8350661
28	DDR w/ Access Lists Router(config)# dialer-list 1 protocol ip list 110 Router(config)# access-list 110 permit tcp any any eq smtp Router(config)# access-list 110 permit tcp any any eq telnet Router(config)# int bri0 Router(config-if)# dialer-group 1 SMTP and Telnet will force the router to dial into the ISDN network. All other traffic will be ignored.
29	Verifying ISDN Operation
30	Summary WAN Terms and Connection Types Frame Relay ISDN