Há duas maneiras diferentes de se usar o HDLC (High-Level Data Link Control) em ISDN:
Defina a interface física para executar o HDLC. Em outras palavras, nenhum encapsulamento é definido porque o HDLC é o encapsulamento padrão usado pelo Cisco IOS® Software. Este é o modo original de configurar HDLC com Dial-on-Demand Routing (DDR) e é discutido neste documento.
Use a interface do discador para vincular o protocolo que deseja (nesse exemplo, HDLC) a um discador específico. Este é o método mais novo e permite a uma interface física específica tratar protocolos múltiplos (por exemplo, Point-to-Point Protocol [PPP] e HDLC). Como o protocolo é configurado na interface do discador, a interface física não é restrita. Este método é conhecido como Encapsulamentos múltiplos dinâmicos e discutido em ISDN DDR Utilizando Encapsulamento HDLC com Vários Encapsulamentos Dinâmicos.
Não existem requisitos específicos para este documento.
As informações neste documento são baseadas nestas versões de software e hardware:
Os roteadores taxbol e goya são 2500 Series Routers usados em um ambiente de laboratório com as configurações apagadas.
O Cisco IOS Software Release 11.2(22) é utilizado em ambos os roteadores.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Para obter mais informações sobre convenções de documento, consulte as Convenções de dicas técnicas Cisco.
A razão pela qual um usuário exige o HDLC no ISDN não é óbvia, porque ele que tem muitas desvantagens em comparação ao PPP. A única finalidade é simplificar a configuração. Contudo, ele também simplifica o acesso ao roteador para todos os hackers. Como HDLC não oferece suporte a nenhum tipo de autenticação, a melhor proteção aqui seria verificar o número chamado com o comando isdn caller na interface. Consulte Configuração de Triagem CLI ou Autenticação ISDN e Retorno de Chamada com ID de Chamador para obter informações adicionais. A autenticação com base em CLID (Identificação de Linha Chamadora) admite que sua Telco fornece o número chamador nas mensagens de instalação ISDN. Contudo, como muitas Telcos não fornecem CLID, verifique com sua Telco antes que você configure a triagem baseada no CLID. Se o CLID não for fornecido pela Telco, todas as chamadas recebidas no roteador falharão.
Uma outra desvantagem do HDLC é que o roteador não instala um mapa dinâmico. Por isso, um mapa de discadores precisa ser configurado (em cada extremidade) para o peer HDLC.
Observação: se apenas um lado fizer a chamada (por exemplo, um roteador sempre aceita a chamada e não disca), certifique-se de incluir um nome para o peer remoto na instrução dialer map do lado receptor. Contudo, o nome pode ser um nome falsificado porque que o roteador não tem nenhuma maneira de autenticar o nome do peer para determinar se corresponde ao nome de mapa de discadores.
Por exemplo, esta é uma descrição e este número ISDN é 8130.
ip address 172.16.1.6 255.255.255.252 isdn caller 8129 !--- This is to accept only calls from 8129. dialer map ip 172.16.1.5 name bogus_to_accept_command !--- This is a dialer-map with a fake name. dialer-group 1
Nesta seção, você encontrará informações para configurar os recursos descritos neste documento.
Observação: para encontrar informações adicionais sobre os comandos usados neste documento, use a ferramenta Command Lookup
Este documento utiliza a configuração de rede mostrada neste diagrama.
goya |
---|
Current configuration: ! version 11.2 service timestamps debug datetime msec service timestamps log datetime msec ! hostname goya ! isdn switch-type basic-net3 !--- The switch-type used is basic-net3. If you are in the United States, !--- configure the correct switch-type (for example !--- isdn switch-type basic-5ess). In the US, you also need to !--- configure the spids under the Basic Rate Interface (BRI) interface. ! interface Ethernet0 ip address 10.1.1.1 255.255.255.0 no ip redirects ! interface BRI0 !--- If you are in the US do not forget the SPID !--- (for example isdn spid1 01555.....) description This ISDN number is 8129 ip address 172.16.1.5 255.255.255.252 dialer idle-timeout 60 !--- The idle is set to 60 seconds. isdn caller 8130 !--- Verify the incoming number since there is no authentication on HDLC. dialer map ip 172.16.1.6 8130 !--- This side is making the call to 8130. dialer-group 1 ! ip classless ip route 0.0.0.0 0.0.0.0 172.16.1.6 access-list 105 permit icmp any any !--- This access-list is to debug ICMP only. dialer-list 1 protocol ip permit ! line con 0 exec-timeout 0 0 transport input none line aux 0 line vty 0 4 exec-timeout 0 0 no login ! end |
traxbol |
---|
Current configuration: ! version 11.2 service timestamps debug datetime msec service timestamps log datetime msec ! hostname traxbol ! isdn switch-type basic-net3 !--- The switch-type used here is basic-net3. If you are in the United States, !--- configure the correct switch-type (for example !--- isdn switch-type basic-5ess). In the United States, you also need to !--- configure the SPIDs under the BRI interface. ! Interface Ethernet0 ip address 10.1.2.1 255.255.255.0 no ip redirects ! interface BRI0 !--- If you are in the United States, do not forget the SPID !--- (for example isdn spid1 01555.....). description This ISDN number is 8130 ip address 172.16.1.6 255.255.255.252 isdn caller 8129 !--- Verify the incoming number since there is no authentication on HDLC. dialer map ip 172.16.1.5 name goya !--- This side will not make any calls, but "name goya" is added to complete the !--- command. This is because a static dialer map is necessary. dialer-group 1 ! ip classless ip route 0.0.0.0 0.0.0.0 172.16.1.5 access-list 105 permit icmp any any !--- This access-list is to debug ICMP only. dialer-list 1 protocol ip permit ! line con 0 exec-timeout 0 0 line aux 0 line vty 0 4 exec-timeout 0 0 password ww login ! end |
Esta seção fornece informações que você pode usar para confirmar se sua configuração funciona adequadamente.
A Output Interpreter Tool (somente clientes registrados) oferece suporte a determinados comandos show, o que permite exibir uma análise da saída do comando show.
show interfaces bri number- Especificar somente o número exibe o canal D para essa interface BRI.
Comando | Descrição |
---|---|
número | Número da interface. O valor é de 0 a 7 se o roteador tiver um NIM BRI de 8 portas, ou de 0 a 15 se o roteador tiver dois NIMs BRI de 8 portas. Os valores do número de interface variam, baseados na plataforma de hardware usada. O Cisco 3600 Series Router, por exemplo, pode ter até 48 interfaces. |
Como nenhum encapsulamento foi definido na configuração, por padrão é HDLC. Isso pode ser verificado com o comando show interface como mostrado aqui:
goya#show interfaces bri 0 BRI0 is up, line protocol is up (spoofing) Hardware is BRI Description: This ISDN number is 8129 Internet address is 172.16.1.5/30 MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation HDLC, loopback not set !--- HDLC is configured automatically Last input 00:00:00, output 00:00:00, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0 (size/max/drops); Total output drops: 0 Queueing strategy: weighted fair Output queue: 0/1000/64/0 (size/max total/threshold/drops) Conversations 0/1/256 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 3933 packets input, 20462 bytes, 0 no buffer Received 15 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 3926 packets output, 26100 bytes, 0 underruns 0 output errors, 0 collisions, 10 interface resets 0 output buffer failures, 0 output buffers swapped out 7 carrier transitions
Esta seção fornece informações que podem ser usadas para o troubleshooting da sua configuração.
Observação: antes de inserir o comando debug, consulte Informações importantes sobre os comandos debug.
debug dialer
debug ip packet detail 105 —Usado para depurar pacotes IP que são somente ICMP (consulte a lista de acesso 105 na configuração).
debug isdn q931 — Usado para ver o evento e pacotes ISDN Q.931.
debug serial interface — Usado para debugar o HDLC.
Exemplos de debugação de ambos os roteadores são mostrados aqui:
A saída de goya:
goya#debug dialer Dial on demand events debugging is on goya#debug ip packet detail 105 IP packet debugging is on (detailed) for access list 105 goya#debug isdn q931 ISDN Q931 packets debugging is on !--- Verify that the map is correctly configured. goya#show dialer map Static dialer map ip 172.16.1.6 name traxbol (8130) on BRI0 goya#ping? 172.16.1.6 !--- Ping to the remote destination. Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.1.6, timeout is 2 seconds: *Mar? 1 05:40:07.230: IP: s=172.16.1.5 (local), d=172.16.1.6 (BRI0), len 100, sending !--- The Ping attempts to leave the router. *Mar? 1 05:40:07.234:???? ICMP type=8, code=0 *Mar? 1 05:40:07.238: BRI0: Dialing cause ip (s=172.16.1.5, d=172.16.1.6) *Mar? 1 05:40:07.238: BRI0: Attempting to dial 8130 !--- The dialer attempts the call. *Mar? 1 05:40:07.242: IP: s=172.16.1.5 (local), d=172.16.1.6 (BRI0), Len 100, encapsulation failed !--- This is because the HDLC is not ready. !--- Therefore, the encapsulation failed. *Mar? 1 05:40:07.246:???? ICMP type=8, code=0 *Mar? 1 05:40:07.258: ISDN BR0: TX ->? SETUP pd = 8? callref = 0x37 *Mar? 1 05:40:07.258:???????? Bearer Capability i = 0x8890 *Mar? 1 05:40:07.262:???????? Channel ID i = 0x83 *Mar? 1 05:40:07.266:???????? Called Party Number i = 0x80, '8130' *Mar? 1 05:40:07.318: ISDN BR0: RX <-? CALL_PROC pd = 8? callref = 0xB7 *Mar? 1 05:40:07.322:???????? Channel ID i = 0x89 *Mar? 1 05:40:07.470: ISDN BR0: RX <-? CONNECT pd = 8? callref = 0xB7 *Mar? 1 05:40:07.486: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up *Mar? 1 05:40:07.514: ISDN BR0: TX ->? CONNECT_ACK pd = 8? callref = 0x37 !--- The call is made. *Mar? 1 05:40:07.!!!! !--- One ping packet was lost because the encapsulation was not ready. Success rate is 80 percent (4/5), round-trip min/avg/max = 52/58/76 ms goya#.518: dialer Protocol up for BR0:1 *Mar? 1 05:40:07.526: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to up *Mar? 1 05:40:09.230: IP: s=172.16.1.5 (local), d=172.16.1.6 (BRI0), Len 100, sending *Mar? 1 05:40:09.234:???? ICMP type=8, code=0 *Mar? 1 05:40:09.278: IP: s=172.16.1.6 (BRI0), d=172.16.1.5 (BRI0), Len 100, rcvd 3 *Mar? 1 05:40:09.278:???? ICMP type=0, code=0 *Mar? 1 05:40:09.282: IP: s=172.16.1.5 (local), d=172.16.1.6 (BRI0), Len 100, sending *Mar? 1 05:40:09.286:???? ICMP type=8, code=0 *Mar? 1 05:40:09.330: IP: s=172.16.1.6 (BRI0), d=172.16.1.5 (BRI0), Len 100, rcvd 3 *Mar? 1 05:40:09.334:???? ICMP type=0, code=0 *Mar? 1 05:40:09.338: IP: s=172.16.1.5 (local), d=172.16.1.6 (BRI0), Len 100, sending *Mar? 1 05:40:09.338:???? ICMP type=8, code=0 *Mar? 1 05:40:09.406: IP: s=172.16.1.6 (BRI0), d=172.16.1.5 (BRI0), Len 100, rcvd 3 *Mar? 1 05:40:09.410:???? ICMP type=0, code=0 *Mar? 1 05:40:09.414: IP: s=172.16.1.5 (local), d=172.16.1.6 (BRI0), Len 100, sending *Mar? 1 05:40:09.418:???? ICMP type=8, code=0 *Mar? 1 05:40:09.462: IP: s=172.16.1.6 (BRI0), d=172.16.1.5 (BRI0), Len 100, rcvd 3 !--- Other four ping packets are successful. *Mar? 1 05:40:09.466:???? ICMP type=0, code=0 goya# *Mar? 1 05:40:13.674: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 8130 traxbol !? !--- View the dialer. ! goya#show dialer BRI0 - dialer type = ISDN Dial String????? Successes?? Failures??? Last called?? Last status 8130?????????????????? 299???????? 10??? 00:00:11?????? successful 0 incoming call(s) have been screened. BRI0:1 - dialer type = ISDN Idle timer (60 secs), Fast idle timer (20 secs) Wait for carrier (30 secs), Re-enable (15 secs) Dialer state is data link layer up !--- The next two lines tell who triggered the call !--- and the time remaining before disconnect. Dial reason: ip (s=172.16.1.5, d=172.16.1.6) Time until disconnect 50 secs Connected to 8130 (traxbol) BRI0:2 - dialer type = ISDN Idle timer (60 secs), Fast idle timer (20 secs) Wait for carrier (30 secs), Re-enable (15 secs) Dialer state is idle goya# ! !--- View the HDLC. ! goya#debug serial interface? Serial network interface debugging is on goya#ping 172.16.1.6 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.1.6, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 32/93/328 ms goya# *Mar? 1 06:35:03.266: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up *Mar? 1 06:35:03.814: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to up *Mar? 1 06:35:04.822: BRI0:1: HDLC myseq 0, mineseen 0, yourseen 0, line up? *Mar? 1 06:35:09.846: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 8130 traxbol *Mar? 1 06:35:14.826: BRI0:1: HDLC myseq 1, mineseen 1*, yourseen 1, line up? *Mar? 1 06:35:24.838: BRI0:1: HDLC myseq 2, mineseen 2*, yourseen 2, line up? *Mar? 1 06:35:34.842: BRI0:1: HDLC myseq 3, mineseen 3*, yourseen 3, line up? *Mar? 1 06:35:44.846: BRI0:1: HDLC myseq 4, mineseen 4*, yourseen 4, line up? *Mar? 1 06:35:54.850: BRI0:1: HDLC myseq 5, mineseen 5*, yourseen 5, line up? *Mar? 1 06:36:03.862: %ISDN-6-DISCONNECT: Interface BRI0:1? disconnected from 8130 traxbol, call lasted 60 seconds *Mar? 1 06:36:03.974: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down *Mar? 1 06:36:04.858: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to down goya#undebug all All possible debugging has been turned off goya#
A saída de traxbol:
traxbol#debug dialer Dial on demand events debugging is on traxbol#debug ip packet detail 105 IP packet debugging is on (detailed) for access list 105 traxbol#debug isdn q931 ISDN Q931 packets debugging is on !--- Verify that the map is correctly configured. traxbol#show dialer map Static dialer map ip 172.16.1.5 name goya (8129) on BRI0 traxbol# !--- A call is received, notice that the calling party !--- matches the ISDN caller configuration. *Mar? 1 05:40:30.898: ISDN BR0: RX <-? SETUP pd = 8? callref = 0x15 *Mar? 1 05:40:30.898:???????? Bearer Capability i = 0x8890 *Mar? 1 05:40:30.902:???????? Channel ID i = 0x89 *Mar? 1 05:40:30.906:???????? Calling Party Number i = 0xA1, '8129' *Mar? 1 05:40:30.906:???????? Called Party Number i = 0xC1, '8130' *Mar? 1 05:40:30.918: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up *Mar? 1 05:40:30.954: ISDN BR0: TX ->? CONNECT pd = 8? callref = 0x95 *Mar? 1 05:40:30.958: dialer Protocol up for BR0:1 *Mar? 1 05:40:31.014: ISDN BR0: RX <-? CONNECT_ACK pd = 8? callref = 0x15 *Mar? 1 05:40:31.018:???????? Channel ID i = 0x89 *Mar? 1 05:40:31.862: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to up !--- debug ip packet detail 105 shows the ICMPs on this router. *Mar? 1 05:40:32.794: IP: s=172.16.1.5 (BRI0), d=172.16.1.6 (BRI0), Len 100, rcvd 3 *Mar? 1 05:40:32.798:???? ICMP type=8, code=0 *Mar? 1 05:40:32.802: IP: s=172.16.1.6 (local), d=172.16.1.5 (BRI0), Len 100, sending *Mar? 1 05:40:32.802:???? ICMP type=0, code=0 *Mar? 1 05:40:32.850: IP: s=172.16.1.5 (BRI0), d=172.16.1.6 (BRI0), Len 100, rcvd 3 *Mar? 1 05:40:32.854:???? ICMP type=8, code=0 *Mar? 1 05:40:32.854: IP: s=172.16.1.6 (local), d=172.16.1.5 (BRI0), Len 100, sending *Mar? 1 05:40:32.858:???? ICMP type=0, code=0 *Mar? 1 05:40:32.926: IP: s=172.16.1.5 (BRI0), d=172.16.1.6 (BRI0), Len 100, rcvd 3 *Mar? 1 05:40:32.930:???? ICMP type=8, code=0 *Mar? 1 05:40:32.930: IP: s=172.16.1.6 (local), d=172.16.1.5 (BRI0), Len 100, sending *Mar? 1 05:40:32.934:???? ICMP type=0, code=0 *Mar? 1 05:40:32.982: IP: s=172.16.1.5 (BRI0), d=172.16.1.6 (BRI0), Len 100, rcvd 3 *Mar? 1 05:40:32.982:???? ICMP type=8, code=0 *Mar? 1 05:40:32.986: IP: s=172.16.1.6 (local), d=172.16.1.5 (BRI0), Len 100, sending *Mar? 1 05:40:32.990:???? ICMP type=0, code=0 *Mar? 1 05:40:36.994: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 8129 goya ! !--- On the dialer, the call is received. !--- There is no dial reason. However, the idle has been using the !--- default 120 seconds since nothing was configured. !--- The router GOYA closes !--- the call earlier because the idle is set to 60 seconds on that side. ! traxbol#show dialer BRI0 - dialer type = ISDN Dial String????? Successes?? Failures??? Last called?? Last status 8129???????????????????? 0????????? 0??? never?????????????????? - 10 incoming call(s) have been screened. BRI0:1 - dialer type = ISDN Idle timer (120 secs), Fast idle timer (20 secs) Wait for carrier (30 secs), Re-enable (15 secs) Dialer state is data link layer up Time until disconnect 103 secs Connected to 8129 (goya) BRI0:2 - dialer type = ISDN Idle timer (120 secs), Fast idle timer (20 secs) Wait for carrier (30 secs), Re-enable (15 secs) Dialer state is idle traxbol# ! !--- View the HDLC. ! traxbol#debug serial interface Serial network interface debugging is on traxbol# *Mar? 1 06:35:26.674: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up *Mar? 1 06:35:26.698: Ser-Autodetect BR0:1: no autodetect configuration *Mar? 1 06:35:27.534: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to up *Mar? 1 06:35:31.554: BRI0:1: HDLC myseq 0, mineseen 0*, yourseen 1, line up? *Mar? 1 06:35:33.578: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 8129 goya *Mar? 1 06:35:41.598: BRI0:1: HDLC myseq 1, mineseen 1*, yourseen 2, line up? *Mar? 1 06:35:51.702: BRI0:1: HDLC myseq 2, mineseen 2*, yourseen 3, line up? *Mar? 1 06:36:01.746: BRI0:1: HDLC myseq 3, mineseen 3*, yourseen 4, line up? *Mar? 1 06:36:11.790: BRI0:1: HDLC myseq 4, mineseen 4*, yourseen 5, line up? *Mar? 1 06:36:21.894: BRI0:1: HDLC myseq 5, mineseen 5*, yourseen 6, line up? *Mar? 1 06:36:27.510: %ISDN-6-DISCONNECT: Interface BRI0:1? disconnected from 8129 goya, call lasted 60 seconds *Mar? 1 06:36:27.514: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down *Mar? 1 06:36:27.922: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to down traxbol#undebug all All possible debugging has been turned off traxbol#