Completing an ISDN BRI Call. 2000, Cisco Systems, Inc. 13-1

Transcription

1 Completing an ISDN BRI Call 2000, Cisco Systems, Inc. 13-1

2 Objectives Upon completion of this chapter, you will be able to perform the following tasks:? Describe the components that make up ISDN connectivity? Configure ISDN BRI and legacy dial-ondemand routing (DDR)? Verify DDR operation 2000, Cisco Systems, Inc. ICND v1.0a 13-2

3 What is ISDN? Voice, data, video, and special services 2000, Cisco Systems, Inc. ICND v1.0a 13-3

4 ISDN Standards Issue Telephone Network and ISDN ISDN Concepts, Aspects, and Interfaces Switching and Signaling Protocol E-Series I-Series Q-Series Key Examples E.163 International Telephone Numbering Plan E.164 International ISDN Addressing I.100 Series Concepts, Structures, Terminology I.400 User-Network Interfaces (UNIs) Q.921 LAPD (Link Access Procedure on the D channel) Q.931 ISDN Network Layer between Terminal and Switch Standards from the ITU (formerly CCITT) 2000, Cisco Systems, Inc. ICND v1.0a 13-4

5 ISDN Access Options Channel B D Capacity 64 kbps 16/64 kbps Mostly Used for Circuit-switched data (HDLC, PPP) Signaling information (LAPD) BRI D 2B NT1 Service provider network PRI CSU/DSU D 23 or 30B BRI and PRI are used globally for ISDN 2000, Cisco Systems, Inc. ICND v1.0a 13-5

6 BRI Call Processing 2000, Cisco Systems, Inc. ICND v1.0a 13-6

7 ISDN Functions and Reference Points TE1 ISDN Terminal NT2 NT1 Local loop S T U Service provider network TE2 Existing Terminal R TA Terminal Adapter? Functions are devices or hardware? Reference points are demarcations or interfaces 2000, Cisco Systems, Inc. ICND v1.0a 13-7

8 Cisco ISDN BRI Interfaces Native ISDN interface int bri 0 TE1 bri 0 S/T NT1 Service provider network TE1 NT1 bri 0 U TE2 R S0 TA S/T NT1 Nonnative ISDN interface int serial 0 (EIA/TIA-232, V.35, X.21) 2000, Cisco Systems, Inc. ICND v1.0a 13-8

9 ISDN Switch Types S S S S S S S S S CO S S S S CO Many providers and switch types Services vary by regions and countries 2000, Cisco Systems, Inc. ICND v1.0a 13-9

10 Configuring ISDN BRI Step 1: Specify the ISDN switch type Router(config)#isdn switch-type switch-type Router(config-if)#isdn switch-type switch-type? Specifies the type of ISDN switch with which the router communicates? Other configuration requirements vary for specific providers 2000, Cisco Systems, Inc. ICND v1.0a 13-10

11 Configuring ISDN BRI (cont.) Step 2: (Optional) Setting SPIDs Router(config-if)#isdn spid1 spid-number [ ldn ]? Sets a B channel SPID required by many service providers Router(config-if)#isdn spid2 spid-number [ ldn ]? Sets a SPID for the second B channel 2000, Cisco Systems, Inc. ICND v1.0a 13-11

12 Written Exercise BRI 0 S 0 Customer Premises Local Loop Service Provider Label the functional elements and reference points 2000, Cisco Systems, Inc. ICND v1.0a 13-12

13 Written Exercise: Answers BRI 0 S/T NT1 U S 0 R TA S/T NT1 U Customer Premises Local Loop Service Provider Label the functional elements and reference points 2000, Cisco Systems, Inc. ICND v1.0a 13-13

14 What Is Dial-on-Demand Routing? Corporate Dallas I need to send data to Dallas. PSTN ISDN Chicago? Connect when needed? Disconnect when finished? ISDN or PSTN 2000, Cisco Systems, Inc. ICND v1.0a 13-14

15 When to Use DDR Telecommuter Headquarters? Periodic connections? Small amounts of data Vendor 2000, Cisco Systems, Inc. ICND v1.0a 13-15

16 Generic DDR Operation Interesting packet arrives DCE 1. Route to destination is determined 2000, Cisco Systems, Inc. ICND v1.0a 13-16

17 Generic DDR Operation Interesting packet arrives DCE 1. Route to destination is determined 2. Interesting packets dictate DDR call 2000, Cisco Systems, Inc. ICND v1.0a 13-17

18 Generic DDR Operation Interesting packet arrives Dial connection DCE ISDN or Basic Service 1. Route to destination is determined 2. Interesting packets dictate DDR call 3. Dialer information is looked up 2000, Cisco Systems, Inc. ICND v1.0a 13-18

19 Generic DDR Operation 1. Route to destination is determined 2. Interesting packets dictate DDR call 3. Dialer information is looked up 4. Traffic is transmitted 5. Call is terminated 2000, Cisco Systems, Inc. ICND v1.0a 13-19

20 Configuring Legacy DDR Interesting packet arrives DCE 1 Define static routes What route do I use? 2000, Cisco Systems, Inc. ICND v1.0a 13-20

21 Configuring Legacy DDR Interesting packet arrives DCE 1 2 Define static routes What route do I use? Specify interesting traffic What traffic enables the link? 2000, Cisco Systems, Inc. ICND v1.0a 13-21

22 Configuring DDR Interesting packet arrives Dial connection DCE ISDN or Basic Service Define static routes What route do I use? Specify interesting traffic What traffic enables the link? Configure the dialer information What number do I call? 2000, Cisco Systems, Inc. ICND v1.0a 13-22

23 Task 1: Defining Static Routes (Route to Destination) Subnet Home bri ISDN Subnets Central bri ip route ip route ip route Specify address of next hop router Network prefix and prefix mask 2000, Cisco Systems, Inc. ICND v1.0a 13-23

24 Task 2: Specifying Interesting Traffic (What Enables the Connection?) Without Access Lists dialer-list 1 protocol ip permit Any IP traffic will initiate the link With Access Lists (for better control) dialer-list 1 protocol ip list 101 access-list 101 deny tcp any any eq ftp access-list 101 deny tcp any any eq telnet access-list 101 permit ip any any Deny FTP Deny Telnet Any IP traffic, except FTP and Telnet, will initiate the link 2000, Cisco Systems, Inc. ICND v1.0a 13-24

25 Task 3: Configuring the Dialer Information hostname Home! isdn switch-type basic-5ess! username central password cisco interface BRI0 ip address encapsulation ppp dialer idle-timeout 180 dialer map ip name Central dialer-group 1 no fair-queue ppp authentication chap! router rip network ! no ip classless ip route ip route ! dialer-list 1 protocol ip permit Applies rules defined by dialerlist to individual interfaces Both values must match 2000, Cisco Systems, Inc. ICND v1.0a 13-25

26 Task 3: Configuring the Dialer Information (cont.) How do I get to subnetwork ? Home bri ISDN Subnets Central bri interface BRI0 ip address encapsulation ppp dialer idle-timeout 180 dialer map ip name Central dialer-group 1 no fair-queue ppp authentication chap Number to dial Remote host name Used for PPP CHAP 2000, Cisco Systems, Inc. ICND v1.0a 13-26

27 Legacy DDR Configuration Tasks Summarized hostname Home! isdn switch-type basic-5ess! username central password cisco interface BRI0 ip address encapsulation ppp dialer idle-timeout 180 dialer map ip name Central dialer-group 1 no fair-queue ppp authentication chap! router rip network ! no ip classless ip route ip route dialer-list 1 protocol ip permit! 2000, Cisco Systems, Inc. ICND v1.0a 13-27

28 Optional Legacy DDR Commands Router(config-if)#dialer load-threshold load [ outbound inbound either ]? Establishes the amount of traffic on link before a second link is enabled Router(config-if)#dialer idle-timeout seconds? Establishes the idle time before disconnect 2000, Cisco Systems, Inc. ICND v1.0a 13-28

29 Legacy DDR Using ACLs Configuration Example access-list 101 permit tcp any any eq smtp access-list 101 permit tcp any any eq telnet dialer-list 1 list 101! ip route ip route ! interface bri 0 ip address dialer-group 1 dialer map ip name B ! dialer idle-timeout 300 Access list defining interesting packets on Cisco A Static routes to reach destination Interface configuration for DDR Time to wait before dropping call A ISDN B Subnets , Cisco Systems, Inc. ICND v1.0a 13-29

30 Verifying Legacy DDR and ISDN Operation Router#ping or telnet Router#show dialer Triggers a link (assuming it is part of interesting traffic) Displays current status of link, including amount of time link is connected Router#show isdn active When using ISDN, displays call status while call is in progress Router#show isdn status Displays the status of an ISDN connection Router#show ip route Displays all routes, including static routes 2000, Cisco Systems, Inc. ICND v1.0a 13-30

31 Verifying Legacy DDR and ISDN Operation (cont.) Router#debug isdn q921 Shows ISDN layer 2 messages Router#debug isdn q931 Router#debug dialer Shows ISDN call setup and teardown activity Shows call setup and teardown activity Router(config-if)#shutdown Clears currently established connections from the interface 2000, Cisco Systems, Inc. ICND v1.0a 13-31