【正文】 02 broadcast !五、ISDN 1. 綜合數(shù)字業(yè)務(wù)網(wǎng)（ISDN）綜合數(shù)字業(yè)務(wù)網(wǎng)（ISDN）由數(shù)字電話和數(shù)據(jù)傳輸服務(wù)兩部分組成，一般由電話局提供這種服務(wù)。BRI的B信道速率為64Kbps,用于傳輸用戶數(shù)據(jù)。在北美和日本，ISDN的主速率接口（PRI）提供23個B信道和1個D信道，其中D信道速率為64Kbps。我國電話局所提供ISDN PRI為30B+D。 按區(qū)域分關(guān)鍵字 basicts013 Australian TS013 switches Europe covers the EuroISDN EDSS1 signalling system primarynet5 NET5 switches (UK and Europe) vn2 French VN2 ISDN switches vn3 French VN3 ISDN switches Japan basic5ess ATamp。T 4ESS switch type for the . (ISDN PRI only) primary5ess ATamp。 basicnznet3 New Zealand Net3 switches 3. ISDN實現(xiàn)DDR（dialondemand routing）實例:設(shè)置如下：Router1:hostname router1 user router2 password cisco ! isdn switchtype basicnet3 ! interface bri 0 ip address encapsulation ppp dialer map ip name router2 572 dialer loadthreshold 80 ppp multilink dialergroup 1 ppp authentication chap ！ dialerlist 1 protocol ip permit ! Router2: hostname router2 user router1 password cisco ! isdn switchtype basicnet3 ! interface bri 0 ip address encapsulation ppp dialer map ip name router1 571 dialer loadthreshold 80與回撥相關(guān)命令: 任務(wù) 命令 映射協(xié)議地址和電話號碼，并在接口上使用在全局模式下定義的PPP回撥的映射類別。dialer callbackserver [username] 設(shè)置接口要求PPP回撥 ppp callback request ppp multilink dialergroup 1 ppp authentication chap ！ dialerlist 1 protocol ip permit ! 相關(guān)調(diào)試命令： debug dialer debug isdn event debug isdn q921 debug isdn q931 debug ppp authentication debug ppp error debug ppp negotiation debug ppp packet show dialer show isdn status 舉例:執(zhí)行debug dialer命令觀察router2呼叫router1,router1回撥router2的過程. router1debug dialer router2ping router1 00:03:50: %LINK3UPDOWN: Interface BRI0:1, changed state to up 00:03:50: BRI0:1:PPP callback Callback server starting to router2 572 00:03:50: BRI0:1: disconnecting call 00:03:50: %LINK3UPDOWN: Interface BRI0:1, changed state to down 00:03:50: BRI0:1: disconnecting call 00:03:50: BRI0:1: disconnecting call 00:03:51: %LINK3UPDOWN: Interface BRI0:2, changed state to up 00:03:52: callback to router2 already started 00:03:52: BRI0:2: disconnecting call 00:03:52: %LINK3UPDOWN: Interface BRI0:2, changed state to down 00:03:52: BRI0:2: disconnecting call 00:03:52: BRI0:2: disconnecting call 00:04:05: : Callback timer expired 00:04:05: BRI0:beginning callback to router2 572 00:04:05: BRI0: Attempting to dial 572 00:04:05: Freeing callback to router2 572 00:04:05: %LINK3UPDOWN: Interface BRI0:1, changed state to up 00:04:05: BRI0:1: No callback negotiated 00:04:05: %LINK3UPDOWN: Interface VirtualAccess1, changed state to up 00:04:05: dialer Protocol up for Vi1 00:04:06: %LINEPROTO5UPDOWN: Line protocol on Interface BRI0:1, changed state to up 00:04:06: %LINEPROTO5UPDOWN: Line protocol on Interface VirtualAccess1, chang ed state to up 00:04:11: %ISDN6CONNECT: Interface BRI0:1 is now connected to 572 router1 4. ISDN訪問首都在線263網(wǎng)實例: ,屬于保留地址，通過NAT地址翻譯功能，局域網(wǎng)用戶可以通過ISDN上263網(wǎng)訪問Internet。 設(shè)定登錄263的用戶名和口令 ppp pap sentusername 263 password 263 設(shè)定默認路由 ip route bri 0 設(shè)定符合訪問列表2的所有源地址被翻譯為bri 0所擁有的地址 ip nat inside source list 2 interface bri 0 overload 設(shè)定訪問列表2，允許所有協(xié)議 accesslist 2 permit any 具體配置如下：hostname Cisco2503 ! isdn switchtype basicnet3 ! ip subnetzero no ip domainlookup ip routing ! interface Ethernet 0 ip address ip nat inside no shutdown ! interface Serial 0 shutdown no description no ip address ! interface Serial 1 shutdown no description no ip address ! interface bri 0 ip address negotiated ip nat outside encapsulation ppp ppp authentication pap callin ppp multilink dialergroup 1 dialer holdqueue 10 dialer string 2633set system c765c765 set multidestination onc765 set switch net3c765 set ppp multilink onc765 cd lanc765:LAN set ip routing onc765:LAN set ip address c765:LAN set ip netmask c765:LAN set briding offc765:LANcdc765 set user remotenetNew user remotenet being createdc765:remotenet set ip routing onc765:remotenet set bridging offc765:remotenet set ip framing nonec765:remotenet set ppp clientname 263c765:remotenet set ppp password clientEnter new Password: 263ReType new Password: 263c765:remotenet set ppp authentication out nonec765:remotenet set ip address c765:remotenet set ip netmask c765:remotenet set ppp address negotiation local onc765:remotenet set ip pat onc765:remotenet set ip route destination c765:remotenet set number 2633c765:remotenet set active命令描述如下： 任務(wù) 命令 設(shè)置路由器系統(tǒng)名稱 set system c765 允許路由器呼叫多個目的地 set multidestination on 設(shè)置ISDN交換機類型為NET3 set switch net3 允許點到點間多條通道連接實現(xiàn)負載均衡 set ppp multilink on 關(guān)掉橋接 set briding off 建立用戶預(yù)制文件用于設(shè)置撥號連接參數(shù) 可以設(shè)置多個用戶預(yù)制文件用于相同的物理端口對應(yīng)于不同的連接。電話網(wǎng)絡(luò)的應(yīng)用一般可分為兩種類型，一種是同等級別機構(gòu)之間以按需撥號(DDR)的方式實現(xiàn)互連，一種是ISP為撥號上網(wǎng)為用戶提供的遠程訪問服務(wù)的功能。 Server基本設(shè)置：選用Cisco2511作為訪問服務(wù)器,。 相關(guān)調(diào)試命令： show interface show line . Access Server通過Tacacs服務(wù)器實現(xiàn)安全認證：使用一臺WINDOWS NT服務(wù)器作為Tacacs服務(wù)器，,運行Cisco2511隨機帶的Easy ACS .相關(guān)設(shè)置：任務(wù) 命令 激活A(yù)AA訪問控制 aaa newmodel 用戶登錄時默認起用Tacacs+做AAA認證 aaa authentication login default tacacs+ 列表名為no_tacacs使用ENABLE口令做認證 aaa authentication login no_tacacs enable 在運行PPP的串行線上采用Tacacs+做認證 aaa authentication ppp default tacacs+ 由TACACS+服務(wù)器授權(quán)運行EXEC aaa authorization exec tacacs+ 由TACACS+服務(wù)器授權(quán)與網(wǎng)絡(luò)相關(guān)的服務(wù)請求。 aaa accounting exec startstop tacacs+ 為與網(wǎng)絡(luò)相關(guān)的服務(wù)需求運行記帳包括SLIP,PPP,PPP NCPs,+服務(wù)器。這里使用tac作為關(guān)鍵字。Router1撥號連接到Router2。同時在Router2中應(yīng)建立一個用戶，以對端路由器主機名作為用戶名，即用戶名應(yīng)為Router1。 相關(guān)命令如下： 任務(wù) 命令 設(shè)置路由器與modem的接口指令 chatscript scriptname EXPECT SEND EXPECT SEND (etc.) 設(shè)置端口在掛斷前的等待時間 dialer idletimeout seconds 設(shè)置協(xié)議地址與電話號碼的映射 dialer map protocol nexthopaddress [name hostname] [broadcast] [modemscript modemregexp] [systemscript systemregexp] [dialstring] 16