adsl技術(shù)

1、ADSL技術(shù),DSL（數(shù)字用戶線路，Digital Subscriber Line）是以銅質(zhì)電話線為傳輸介質(zhì)的傳輸技術(shù)組合，它包括HDSL、SDSL 、VDSL 、ADSL和RADSL等，一般稱之為xDSL。它們主要的區(qū)別就是體現(xiàn)在信號(hào)傳輸速度和距離的不同以及上行速率和下行速率對(duì)稱性的不同這兩個(gè)方面。,What Is a DSL?,VDSL、HDSL、IDSL、SDSL等DSL技術(shù),Maximum data rate and dista

2、nce assume no impairments.Maximum data rate is achieved at shortest distance.Maximum distance is achieved at lowest data rate.,ADSL,ADSL 在一對(duì)銅線上支持上行速率640Kbps到1Mbps，下行速率1Mbps到8Mbps，有效傳輸距離在3－5公里范圍以內(nèi).　　在Internet中，瀏覽Web等客戶

3、/服務(wù)器業(yè)務(wù)的下行數(shù)據(jù)量要大得多，因此適于采用下行高速化的ADSL Modem。,ADSL技術(shù),不對(duì)稱數(shù)字用戶線ADSL作為一種傳輸層的技術(shù)，充分利用現(xiàn)有的銅線資源，在一對(duì)雙絞線上提供上行640kbps下行8Mbps的帶寬，從而克服了傳統(tǒng)用戶的“瓶頸”，實(shí)現(xiàn)了真正意義上的寬帶接入。 ADSL下行帶寬中的一部分可以用于語(yǔ)音，因此，不需要另外的線路就可以打電話。與有線電視線路上提供的類似服務(wù)不同，在使用ADSL時(shí)，不必與鄰居爭(zhēng)奪

4、帶寬。在許多情況下，憑借現(xiàn)有的電話線路就可以應(yīng)用ADSL。,ADSL技術(shù)(cont.),A key feature of ADSL is coexistence with POTS.Transmission of voice and data signals is performed on the same wire pair.Data circuits are offloaded from the voice switch.Sp

5、litter versus microfilter POTS splitter at CO & Microfilters at customer premises,幾種ADSL MODEM接入示意圖,以太網(wǎng)接口外置式ADSL MODEM 接入示意圖,幾種ADSL MODEM接入示意圖(cont.),USB接口外置式ADSL MODEM接入示意圖,幾種ADSL MODEM接入示意圖(cont.),PCI接口內(nèi)置式

6、ADSL MODEM接入示意圖,ADSL Channels and Encoding,Single-carrier modulation technique,CAP Modulation,Multiple-carrier modulation technique,DMT Modulation,ADSL Channels and Encoding(cont.),,Data over ADSL: PPPoE,Data over ADSL:

7、PPPoE (cont.),Data over ADSL: PPPoE (cont.),Data over ADSL: PPPoE (cont.),Ethernet frame carrying PPP frameService provider end:DSLAM for DSL connection terminationAggregation router for PPP session terminationSubscr

8、iber end:DSL modem for DSL connection terminationPPPoE client for PPP session terminationThe client device is the PC or the router at the CPE,Data over ADSL: PPPoE (cont.),IP is assigned to PPPoE client functioning de

9、vice.A CPE router can connect multiple users via a single ADSL connection using NAT/PAT and DHCP.,Configuration of a Cisco Router as the PPPoE Client,Configure an Ethernet interfaceConfigure a dialer interfaceConfigu

10、re PATConfigure DHCP serverConfigure a static default route,Example: CPE as the PPPoE Clientover the Ethernet Interface,Example: CPE as the PPPoE Clientover the Ethernet Interface (cont.),知識(shí)擴(kuò)充,Configuration of a PPP

11、oE Client,PPPoE Client Configuration,Configures the Ethernet interface,interface ethernet number,router(config)#,pppoe enable,router(config-if)#,pppoe-client dial-pool-number number,router(config-if)#,Enables PPPoE on Et

12、hernet interface,Binds a dialer profile to the Ethernet interface,Example: Configuring PPPoE Client,Configuration of the PPPoE DSL Dialer Interface,Configuring the PPPoE Dialer Interface,Configures the dialer interface.,

13、interface dialer number,router(config)#,encapsulation ppp,router(config-if)#,ip address negotiated,router(config-if)#,Specifies PPP encapsulation for the dialer interface.,Sets IP address to be negotiated with the remote

14、 peer using IPCP.,Configuring the PPPoEDialer Interface (Cont.),Binds dialer interface to the dialer pool,dialer pool pool_number,router(config-if)#,ip mtu mtu_size,router(config-if)#,ppp authentication chap [callin],ro

15、uter(config-if)#,Reduces the maximum Ethernet payload size because the PPPoE header requires 8 bytes,(Optional) Configures PPP authentication CHAP,Example: Configuring thePPPoE Dialer Interface,Configuration of PAT,Port

16、 Address Translation,Configure PAT,Specifies the addresses that may be translated,access-list ACL_num {permit | deny} protocol source_network source_wildcard destination_network destination_wildcard,router(config)#,ip na

17、t inside source list ACL_num interface interface number [overload],router(config)#,ip nat {inside | outside},router(config-if)#,Enables dynamic translation of addresses using the assigned IP address of the interface,Spec

18、ifies the interface as inside or outside related to PAT,Example: PAT Configuration,Configuration of DHCP to Scale DSL,Configure a DHCP Server,Enables a DHCP pool for use by hosts and enters DHCP pool configuration mode.,

19、ip dhcp pool pool_name,router(config)#,import all,router(dhcp-config)#,network network_address subnet_mask,router(dhcp-config)#,Imports DNS and WINS information from IPCP.,Specifies the network and subnet mask of the poo

20、l.,default-router address,router(dhcp-config)#,Specifies the default router for the pool to use.,Example: DHCP Server Configuration,Configuration of a Static Default Route,Configuring a Static Default Route,The CPE can u

21、se a static default route to reach all remote destinations.,ip route 0.0.0.0 0.0.0.0 interface number,router(config)#,Example: Static Default Route,Verifying a PPPoE Configuration,Verifying a PPPoE Configuration,Displays

22、 PPPoE protocol messages about events that are part of normal session establishment or shutdown,debug pppoe events,router#,debug ppp authentication,router#,show pppoe session,router#,Displays authentication protocol mess

23、ages, including CHAP and PAP packet exchanges,Displays basic information about currently active PPPoE sessions,Verifying a PPPoE Configuration (Cont.),Displays address bindings on the Cisco IOS DHCP server,show ip dhcp b

24、inding,router#,show ip nat translations,router#,ipconfig /all,C:\Documents and Settings\User>,Displays active NAT translations,Displays the complete IP configuration on Windows NT, 2000, or XP system,,CPE#show pppoe s

25、essionTotal PPPoE sessions 1PPPoE Session InformationUID SID RemMAC Intf Intf Session LocMAC VASt state0 5989 0090.1a41.1a83 Et1 V

26、i2 N/A 000b.46e2.eb36 UP,,Debug VPDN PPPoE Events,CPE#debug pppoe events15:13:41.991: Sending PADI: Interface = Ethernet115:13:42.083: PPPoE 0: I PADO15:13:44.091: PPPOE: we've

27、got our pado and the pado timer went off15:13:44.091: OUT PADR from PPPoE Session15:13:44.187: PPPoE 5989: I PADS15:13:44.187: IN PADS from PPPoE Session,Determine if the PPPoE connect phase is successful.,Get the sta

28、tus of the PPPoE session.,,Debug PPP Authentication,Enable debugging for PPP authentication to verify authentication success.,,CPE#debug ppp authenticationCPE#configure terminalEnter configuration commands, one per lin

29、e. End with CNTL/Z.CPE(config)#interface ATM 0/0CPE(config-if)#no shutdown00:19:05: %LINK-3-UPDOWN: Interface ATM 0/0, changed state to up00:19:06: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0/0, changed sta

30、te to up00:19:29: %DIALER-6-BIND: Interface Vi2 bound to profile Di100:19:29: Vi2 PPP: Using dialer call direction00:19:29: Vi2 PPP: Treating connection as a callout00:19:29: Vi2 PPP: Authorization required00:19:29:

31、 Vi2 PPP: No remote authentication for call-out00:19:29: %LINK-3-UPDOWN: Interface Virtual-Access2, changed state to up00:19:31: Vi2 CHAP: I CHALLENGE id 1 len 24 from "ISP"00:19:31: Vi2 CHAP: Using hostname

32、 from interface CHAP00:19:31: Vi2 CHAP: Using password from AAA00:19:31: Vi2 CHAP: O RESPONSE id 1 len 25 from "CPE"00:19:32: Vi2 CHAP: I SUCCESS id 1 len 400:19:33: %LINEPROTO-5-UPDOWN: Line protocol on In

33、terface Virtual-Access2, changed state to up,,,Verify DHCP Clients,C:\Documents and Settings\User>ipconfig /allWindows 2000 IP ConfigurationEthernet adapter LAB: Connection-specific DNS Suffix . : lab.co

34、m Description . . . . . . . . . . . : Intel(R) PRO/1000 MT Mobile Connection Physical Address. . . . . . . . . : 00-11-25-AF-40-9B Dhcp Enabled. . . . . . . . . . . : Yes Autoconfiguration

35、 Enabled . . . . : Yes IP Address. . . . . . . . . . . . : 10.0.0.2 Subnet Mask . . . . . . . . . . . : 255.0.0.0 Default Gateway . . . . . . . . . : 10.0.0.1 DHCP Server . . . . . . . . .

36、 . . : 10.0.0.1 DNS Servers . . . . . . . . . . . : 192.168.1.1 192.168.1.2 Primary WINS Server . . . . . . . : 192.168.1.3 Lease Obtained. . . . . . .

37、. . . : 6. April 2006 16:36:31 Lease Expires . . . . . . . . . . : 7. April 2006 0:36:31,Verify how the IP address is assigned on the PC.,,Verify DHCP Server,CPE#show ip dhcp bindingIP address Client-ID/

38、 Lease expiration Type Hardware address10.0.0.2 0100.5056.4000.59 Jan 21 2006 12:50 AM Automatic10.0.0.3 0100.5056.4000.60 Jan 21 2006 12:50 AM Automatic,Verify th

39、e existing DHCP bindings on the router (DHCP server).,,Verify how IP addresses are translated on the router.,CPE#show ip nat translationsPro Inside global Inside local Outside local Outside globalicmp

40、 192.168.1.202:512 10.0.0.2:512 192.168.123.100:512 192.168.123.100:512,Verify PAT,,PPPoE Sample Configuration,hostname CPE!ip dhcp pool MyPool network 10.0.0.0 255.0.0.0 default-router 10.0.0.1!interface Et

41、hernet0/1 no ip address pppoe enable pppoe-client dial-pool-number 1!interface Ethernet0/0 ip address 10.0.0.1 255.0.0.0 ip nat inside!interface Dialer0 ip address negotiated encapsulation ppp dialer pool 1

42、ip mtu 1492 ip nat outside ppp authentication chap callin ppp chap password mysecret!ip nat inside source list 101 interface Dialer0 overloadaccess-list 101 permit ip 10.0.0.0 0.255.255.255 any!ip route 0.0.0.0 0