Chapter 7 ISDN and DDR 第一單元 ISDN

What is ISDN? ISDN - Integrated Service Digital Network Small Office Digital PBX Provider Network Telecommuter Home Office Central Site ISDN - Integrated Service Digital Network Integrate Voice/Data/Video services

ISDN Standards Standards from the ITU-T (formerly CCITT) Issue Protocol Key Examples Telephone network and ISDN E.163—International telephone numbering plan E.164—International ISDN addressing E-series ISDN concepts, aspects, and interfaces I.100 Series—Concepts, structures, terminology I.400—User-Network Interfaces (UNIs) I-series Q.921—LAPD (Link Access Procedure on the D channel) Q.931—ISDN network layer between terminal and switch Switching and signaling Q-series Standards from the ITU-T (formerly CCITT)

Signaling information (LAPD) ISDN Access Options Channel Capacity Mostly Used For B 64 kbps Circuit-switched data (HDLC, PPP) D 16/64 kbps Signaling information (LAPD) BRI NT1 Service Provider Network 2B D PRI CSU/DSU 23B or 30B D

ISDN 網路邏輯架構圖 ISDN Functions and Reference Points Local Loop TE1 Service Provider Network S NT-2 T NT-1 U Native ISDN TE2 R TA Terminal Adapter Existing Terminal Functions are devices or hardware. Reference points are demarcations or interfaces

ISDN BRI 網路實體連接圖 Native ISDN Interface - int bri 0 NT-1 TE1 S/T TE1 U Service Provider Network TE1 BRI 0 NT-1 S/T BRI 0 TE1 U NT-1

ISDN PRI 網路實體連接圖 Native ISDN Interface CSU CT1/ PRI-U CT1/ PRI CSU Service Provider Network CT1/ PRI-U CSU CT1/ PRI CSU

Configuring ISDN BRI / PRI

ISDN Switch Types Many providers use many different switch types CO S S S S CO Many providers use many different switch types Services vary by region and country

Configure ISDN BRI Step 1: Specify the ISDN switch type. Router(config)#isdn switch-type switch-type Router(config-if)#isdn switch-type switch-type The command specifies the type of ISDN switch with which the router communicates. (例如: 歐規的 basic net3 或美規的 basic 5ess)

Configure ISDN BRI (cont.) Step 2: (Optional) Setting SPIDs Router(config-if)#isdn spid1 spid-number [ldn] Slide 2 of 2 Purpose: This figure describes how to configure SPIDs. Emphasize: The isdn spid1 and isdn spid2 commands are used on some switches and are replacements for subaddresses. Some service providers require SPIDs to authenticate that a call requests are within contract specifications. SPIDs are required for National ISDN-1 and DMS-100 ISDN switches. Some service providers require that both spid1 and spid2 be specified, while others only require spid1. 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

Configure ISDN PRI T1/E1 PRI Step 1: Specify the ISDN PRI switch type. 23B (T1) or 30B (E1) D Step 1: Specify the ISDN PRI switch type. Router(config)#isdn switch-type switch-type Step 2: Select the T1/E1 controller. Router(config)#controller {t1|e1} slot/port Step 3: Set PRI group timeslots to function as PRI. Router(config-controller)#pri-group timeslots range

ISDN PRI Examples T1 Sample Configuration E1 Sample Configuration Router(config)#controller T1 3/0 Router(config-controller)#framing esf Router(config-controller)#linecode b8zs Router(config-controller)#pri-group timeslots 1-24   Router(config-controller)#interface Serial3/0:23 Router(config-if)#isdn switch-type primary-5ess Router(config-if)#no cdp enable E1 Sample Configuration Router(config)#controller E1 3/0 Router(config-controller)# framing crc4 Router(config-controller)# linecode hdb3 Router(config-controller)# pri-group timeslots 1-31   Router(config-controller)#interface Serial3/0:15 Router(config-if)# isdn switch-type primary-net5 Router(config-if)# no cdp enable

Dial-on-Demand Routing (DDR) 第二單元 Dial-on-Demand Routing (DDR)

What is Dial-on-Demand Routing? Dallas Corporate PSTN Chicago ISDN I need to send data to Dallas. Connects when needed (自動撥號) Disconnects when finished (自動斷線) ISDN or PSTN

使用 DDR 的時機? Periodic connections Small amounts of data Telecommuter Headquarters Periodic connections Small amounts of data Vendor

“Interesting” Packet Arrives DDR 設定三部曲 “Interesting” Packet Arrives Dial Connection DCE ISDN or PSTN Define static routes — What route do I use? 1 Specify “interesting” traffic — What traffic enables the link? 2 Configure dialer information — What number do I call? 3

Step 1: Define Static Routes (What route do I use? ) 10.1.0.1 10.1.0.2 Subnets 10.10.0.0 10.20.0.0 Subnet 10.40.0.0 ISDN Home Central bri 0 5551000 bri 0 5552000 ip route 10.40.0.0 255.255.0.0 10.1.0.1 Specify Address of Next-Hop Router ip route 10.10.0.0 255.255.0.0 10.1.0.2 ip route 10.20.0.0 255.255.0.0 10.1.0.2 Network Prefix and Prefix Mask

Step 2: Specify Interesting Traffic (What traffic enables the link?) dialer-list 1 protocol ip permit Any IP traffic will initiate the link without access lists. 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 linking with access lists (for better control).

Step 2: Specify Interesting Traffic (cont.) hostname Home ! isdn switch-type basic-5ess username central password cisco interface BRI0 ip address 10.1.0.1 255.255.255.0 encapsulation ppp dialer idle-timeout 180 dialer map ip 10.1.0.2 name Central 5552000 dialer-group 1 no fair-queue ppp authentication chap router rip network 10.0.0.0 no ip classless ip route 10.10.0.0 255.255.0.0 10.1.0.2 ip route 10.20.0.0 255.255.0.0 10.1.0.2 dialer-list 1 protocol ip permit Applies rules defined by dialer-list to individual interfaces Both Values Must Match

Step 3: Configure Dialer Information (what number do I call?) How do I get to subnetwork 10.10.0.0? Subnets 10.10.0.0 10.20.0.0 10.1.0.1 10.1.0.2 ISDN Home Central bri 0 5551000 bri 0 5552000 interface BRI0 ip address 10.1.0.1 255.255.255.0 encapsulation ppp dialer idle-timeout 180 dialer map ip 10.1.0.2 name Central 5552000 dialer-group 1 no fair-queue ppp authentication chap Number to Dial Remote Host Name Used for PPP CHAP

Legacy DDR 設定總整理 3 1 2 hostname Home ! isdn switch-type basic-5ess username central password cisco interface BRI0 ip address 10.1.0.1 255.255.255.0 encapsulation ppp dialer idle-timeout 180 dialer map ip 10.1.0.2 name Central 5552000 dialer-group 1 no fair-queue ppp authentication chap no ip classless ip route 10.10.0.0 255.255.0.0 10.1.0.2 ip route 10.20.0.0 255.255.0.0 10.1.0.2 dialer-list 1 protocol ip permit 3 1 2

Optional Legacy DDR Commands Router(config-if)#dialer load-threshold load [outbound | inbound | either] Establishes the amount of traffic on the link before a second B channel is enabled Router(config-if)#dialer idle-timeout seconds Establishes the idle time before disconnect

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 192.168.12.0 255.255.255.0 10.108.126.2 ip route 192.168.14.0 255.255.255.0 10.108.126.2 ! interface bri 0 ip address 10.108.126.1 255.255.255.0 dialer-group 1 dialer map ip 10.108.126.2 name B 5551234 dialer idle-timeout 300 Access list defining interesting packets on Cisco A Static routes to reach destination Purpose: This figure explains how to use access control lists with DDR. Interface configuration for DDR Time to wait before dropping call 10.108.126.1 10.108.126.2 Subnets 192.168.12.0 192.168.14.0 ISDN A B

Verify Legacy DDR and ISDN Operation Triggers a link (assuming it is part of interesting traffic) Router#ping or telnet Displays current status of link, including amount of time link is connected Router#show dialer When using ISDN, displays call status while call is in progress Router#show isdn active Displays the status of an ISDN connection Router#show isdn status Displays all routes, including static routes Router#show ip route

Verify Legacy DDR and ISDN Operation (cont.) Router#debug isdn q921 Shows ISDN Layer 2 messages Router#debug isdn q931 Shows ISDN call setup and teardown activity Shows call setup and teardown activity Router#debug dialer Clears currently established connections from the interface Router(config-if)#shutdown