拨号和接入 : 按需拨号路由 (DDR)

ISDN DDR 使用 HDLC 封装

2015 年 8 月 28 日 - 机器翻译
其他版本: PDFpdf | 英语 (2015 年 4 月 22 日) | 反馈


目录


简介

有两个不同的方式使用在ISDN的高级数据链路控制(HDLC) :

  • 定义物理接口运行HDLC。换句话说,因为HDLC是思科IOS�软件,使用的默认封装封装没有定义。这是原始方式配置与按需拨号路由(DDR)的HDLC和讨论在本文。

  • 绑定您希望的协议的使用拨号接口(在本例中, HDLC)对一特定拨号程序。这是新方法并且允许一个特定物理接口处理多个协议(例如,点对点协议[PPP]和HDLC)。因为协议在拨号接口配置,物理接口没有限制。此方法在ISDN DDR被称作作为动态多重封装和讨论使用HDLC封装与动态多重封装

先决条件

要求

本文档没有任何特定的要求。

使用的组件

本文档中的信息基于以下软件和硬件版本:

  • 路由器taxbol和goya是用于实验室环境清除配置的2500系列路由器。

  • Cisco IOS软件版本11.2(22)在两路由器使用。

本文档中的信息都是基于特定实验室环境中的设备编写的。本文档中使用的所有设备最初均采用原始(默认)配置。如果您使用的是真实网络,请确保您已经了解所有命令的潜在影响。

规则

有关文档规则的详细信息,请参阅 Cisco 技术提示规则

为什么使用 HDLC?

原因为什么用户需要在ISDN的HDLC不是显然的,因为有很多缺点与PPP比较。唯一的目的将简单化配置。然而,它也简化对路由器的访问所有黑客的。HDLC不支持任何验证,因此此处最好的保护是验证呼叫号码用isdn caller命令在您的接口。参考配置Cli放映ISDN认证和回拨与呼叫方ID其他信息的。Calling line ID (CLID)基于验证假设,您的Telco供应在ISDN建立消息的呼叫号码。然而,因为许多Telco不供应CLID,请验证与您的Telco,在您配置基于CLID的过滤前。如果Telco没有供应CLID,则所有呼入呼叫到路由器里发生故障。

HDLC另一个缺点是路由器不安装动态映射。所以, dialer map需要为HDLC对等体配置(在每个末端)。

注意: 如果仅一端做呼叫(例如,一个路由器总是接受呼叫并且不拨出)确保,您在接收端的拨号映射语句包括一名称对于远端对等体。然而,名称可以是一假名称,因为路由器没有方式验证对等体名称确定是否匹配dialer map映射名字。

例如,这是说明,并且此ISDN编号是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 

配置

本部分提供有关如何配置本文档所述功能的信息。

注意: 要寻找关于用于本文的指令的其他信息,请使用命令查找工具

网络图

本文档使用此图所示的网络设置。

/image/gif/paws/10369/bri_ddr_hdlcencap.gif

配置

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

验证

本部分提供的信息可帮助您确认您的配置是否可正常运行。

命令输出解释程序工具仅限注册用户)支持某些 show 命令,使用此工具可以查看对 show 命令输出的分析。

  • show interfaces bri number -指定仅编号显示该BRI接口的D-channel。

    命令 说明
    号码 接口号。值是0至7,如果路由器有一个8端口BRI NIM,或者0至15,如果路由器有两8端口BRI NIMs。接口号值根据使用的硬件平台变化。Cisco 3600系列路由器例如,能有48个接口。

封装未在配置里定义,那么默认情况下它是HDLC。这可以用show interface命令验证如显示此处:

 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

故障排除

本部分提供的信息可用于对配置进行故障排除。

故障排除命令

注意: 在发出 debug 命令之前,请参阅有关 Debug 命令的重要信息

  • debug dialer

  • debug ip packet detail 105 —使用对debug ip是仅ICMP (的数据包请参阅access-list 105在配置里)。

  • debug isdn q931 —用于发现ISDN Q.931事件和数据包。

  • debug serial interface —用于调试HDLC。

两路由器调试示例显示此处:

从goya的输出:

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# 

从traxbol的输出:

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# 

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Document ID: 10369