帧中继到 ATM 与LLQ 、PPP LFI 和cRTP 互工作的 VoIP QoS

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已更新: 2006 年 2 月 2 日

文档 ID:22383

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关于此翻译

思科采用人工翻译与机器翻译相结合的方式将此文档翻译成不同语言，希望全球的用户都能通过各自的语言得到支持性的内容。请注意：即使是最好的机器翻译，其准确度也不及专业翻译人员的水平。 Cisco Systems, Inc. 对于翻译的准确性不承担任何责任，并建议您总是参考英文原始文档（已提供链接）。

简介

本文为VoIP提供了示例配置，使用了PATM的多链路PPP和帧中继互联(VoIP使用了MLPoATM/MLPoFR)。配置示例的中心重点是提供服务质量(QoS)，以便在ATM/帧中继互通WAN上正确支持语音。配置示例还使用压缩实时协议(cRTP)，自Cisco IOS®软件版本12.2(2)T^以来,ATM上一直支持该协议。

文档可以独立阅读，以获取配置指南、配置示例和验证命令，以用于构建网络。提供部分背景信息，供与ATM/帧中继互联相关的特殊事件使用。有关帧中继或PPP上VoIP的QoS的详细信息，请参阅以下文档：

先决条件

要求

尝试进行此配置之前，请确保满足以下要求：

您应熟悉以下技术领域：

访问控制列表
ATM永久虚电路(PVC)
帧中继永久虚电路(数据链路连接标识符(DLCI))
带宽管理
LLQ
LFI
虚拟模板和虚拟接入接口
MLPPP
cRTP

使用的组件

本文档中的信息基于以下软件和硬件版本：

Cisco 3640作为ATM路由器
Cisco 2620作为帧中继路由器
思科IOS软件版本12.2(8)T(IP Plus)

注意： 作为一般准则，最新的Cisco IOS 12.2主线维护版本是推荐的Cisco IOS软件版本，用于MLPoATM/FR。如果使用cRTP，则ATM路由器上需要Cisco IOS软件版本12.2T。

这些Cisco IOS软件版本引入了相关功能：

LFI在Cisco IOS软件版本11.3中引入。
LLQ在思科IOS软件版本12.0(7)T中引入。
在Cisco IOS软件版本12.1(2)T中引入了帧中继上的LLQ和每PVC的ATM。
在Cisco IOS软件版本12.1(5)T中引入了帧中继和ATM虚电路的多链路PPP LFI。
在Cisco IOS软件版本12.2(2)T中引入了基于ATM的cRTP。

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。

背景信息

通过ATM/帧中继网际网络为VoIP提供最小化的端到端延迟和抖动避免的关键问题是：

语音流量的严格优先级(低延迟队列(LLQ))
Link Fragmentation and Interleaving (LFI)
用于语音的帧中继流量整形(FRTS)
ATM 流量整形

这些文档提供了进一步背景信息的有用来源：

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：使用命令查找工具(仅限注册客户)可查找有关本文档中使用的命令的详细信息。

网络图

本文档使用以下网络设置：

配置

本文档使用以下配置：

帧中继连接的路由器
ATM连接路由器

注意：请注意，在此配置中，两台路由器通过帧中继背靠背连接到ATM互通交换机。但是，在大多数拓扑中，支持语音的路由器可以存在于任何位置。通常，语音路由器使用LAN连接到其它路由器，这些路由器连接到ATM/帧WAN。在这些情况下，必须为LLQ、LFI和MLPPP配置连接到WAN、帧中继和ATM的路由器，以便它们能提供QoS，而不是像这些配置所示的语音网关。

帧中继连接的路由器
!--- Note: This configuration is commented and numbered !--- in the order that commands should be entered. version 12.2 service timestamps debug datetime msec service timestamps log uptime no service password-encryption ! hostname FR ! enable password cisco ! username ATM password 0 cisco voice-card 0 dspfarm ! ip subnet-zero ! ! ! ! !--- access-list 105 permit ip any any dscp ef specifies !--- that all traffic with Differentiated Services Code Point (DSCP) !--- are set to 40 falls into this access-list. !--- This class-map command defines a class of traffic called "voice". access-list 105 permit ip any any dscp ef access-list 105 permit udp any any range 16384 32767 access-list 105 permit ip any any precedence critical ! class-map match-all voice match access-group 105 ! ! ! !--- This policy-map command defines a policy for LLQ called "VoIP" and !--- maps the "voice" class to the "VOIP" policy. !--- "priority" defines the amount of bandwidth reserved for the priority queue. !--- "class-default" specifies that the default class is also mapped to this policy. !--- "fair-queue" specifies that all other traffic is served in the WFQ. policy-map VOIP class voice priority 48 class class-default fair-queue !--- Note: Although it is possible to queue various types of !--- real-time traffic to the priority queue, !--- Cisco recommends that you direct only voice traffic !--- to it. Real-time traffic such as video or voice !--- could introduce variations in delay. Please note voice and !--- video should not be combined in the same PVC. !--- (the priority queue is a First In First Out (FIFO) !--- queue). Voice traffic requires that delay be !--- nonvariable in order to avoid jitter. !--- Note: The sum of the values for priority and !--- bandwidth statements needs to be less !--- than or equal to 75% of the link bandwidth. !--- Otherwise service-policy cannot be !--- assigned to the link. When configuring VoIP over a !--- 64 Kbps link to support two !--- voice calls, it is common to allocate more than 75% !--- (48 Kbps) of the link bandwidth to !--- the priority queue. In such cases, you can use the !--- max-reserved-bandwidth <#%> command in order to raise !--- available bandwidth to a value more than 75%. ! ! ! fax interface-type fax-mail mta receive maximum-recipients 0 ! interface Loopback0 ip address 10.1.1.2 255.255.255.0 ! ! interface FastEthernet0/0 ip address 172.17.111.16 255.255.255.224 duplex auto speed auto ! interface Serial0/0 no ip address encapsulation frame-relay IETF no ip route-cache no ip mroute-cache frame-relay traffic-shaping ! !--- Choose the frame relay interface to be !--- associated with the virtual interface. The !--- virtual template could equally have been associated !--- with the physical interface. !--- The "class mlp" associates the virtual template interface !--- defined in "interface Virtual-Template1" with a Frame Relay DLCI. !--- Associates a Frame Relay map class with a DLCI. interface Serial0/0.1 point-to-point no ip route-cache no ip mroute-cache frame-relay interface-dlci 16 ppp Virtual-Template1 class mlp !--- The interface command creates a virtual !--- template called Virtual-Template1. !--- A bandwidth of 64 Kbps is assigned to this !--- template interface. This bandwidth is used !--- by Cisco IOS to calculate the data fragment size as noted regarding !--- interleaving of PPP segments. !--- "ip rtp header-compression"—cRTP is supported in an ATM/Frame Relay Interworking !--- environment. It requires Cisco IOS Software Release 12.2(2)T on the !--- ATM router. !--- "service-policy output VOIP"—The VoIP policy created earlier is assigned !--- to this interface in the outbound direction. !--- PPP multilink is enabled and the !--- maximum delay per segment is specified. This bandwidth is !--- used by Cisco IOS to calculate the data fragement size as noted. !--- Interleaving of PPP segments is enabled, which allows !--- voice packets to be expedited. Voice !--- packets need only wait behind a single segment of !--- a previously queued data packet (for example, 10 ms !--- delay) rather than wait until the end of the !--- entire data packet. Cisco IOS calculates the !--- data fragment size using the following formula: !--- fragment size = delay x bandwidth/8 ! interface Virtual-Template1 bandwidth 64 ip unnumbered loopback0 ip rtp header-compression no ip route-cache load-interval 30 max-reserved-bandwidth 99 service-policy output VOIP ppp multilink ppp multilink fragment-delay 10 ppp multilink interleave ! ! ip classless ip route 0.0.0.0 0.0.0.0 172.17.111.1 no ip http server ip pim bidir-enable ! ! ! !--- A map class called mlp is created. !--- With "no frame-relay adaptive-shaping", adaptive !--- shaping is disabled. You do not !--- want to exceed CIR and have voice packets !--- possibly queued within the Frame Relay network. !--- Waiting for a BECN to resolve this !--- situation could result in poor voice quality. !--- The frame-relay cir 64000 command forces the router to transmit !--- at the desired CIR rate rather than line !--- rate for the port. !--- "frame-relay bc 640" configures the Bc value to force the desired !--- Tc (shaping interval) value is 10 ms. !--- This formula should be used to determine !--- the Bc value to use: Tc = Bc/CIR. A !--- smaller Tc value reduces the interval a voice !--- packet has to wait to be sent. !--- As in "frame-relay be 0", the Be value should be set to zero !--- in order to avoid voice being sent as part of a burst !--- that is not guaranteed by the Frame Relay network. map-class frame-relay mlp no frame-relay adaptive-shaping frame-relay cir 64000 frame-relay bc 640 frame-relay be 0 ! call rsvp-sync ! voice-port 1/0/0 ! voice-port 1/0/1 ! ! mgcp profile default ! dial-peer cor custom ! ! ! dial-peer voice 123 voip destination-pattern 123 session target ipv4:10.1.1.1 ip qos dscp cs5 media ip qos dscp cs5 signaling no vad ! dial-peer voice 456 pots destination-pattern 456 port 1/0/0 ! ! line con 0 line aux 0 line vty 0 4 exec-timeout 0 0 password cisco login ! ! end

帧中继连接的路由器


!--- Note: This configuration is commented and numbered !--- in the order that commands should be entered.


version 12.2
service timestamps debug datetime msec
service timestamps log uptime
no service password-encryption
!
hostname FR
!
enable password cisco
!
username ATM password 0 cisco
voice-card 0
dspfarm
!
ip subnet-zero
!
!
!
!


!--- access-list 105 permit ip any any dscp ef specifies !--- that all traffic with Differentiated Services Code Point (DSCP) !--- are set to 40 falls into this access-list. !--- This class-map command defines a class of traffic called "voice". 

access-list 105 permit ip any any dscp ef 
access-list 105 permit udp any any  range 16384 32767
access-list 105 permit ip any any precedence critical
!
class-map match-all voice 
match access-group 105
!

!         
!

!--- This policy-map command defines a policy for LLQ called "VoIP" and !--- maps the "voice" class to the "VOIP" policy. !--- "priority" defines the amount of bandwidth reserved for the priority queue. !--- "class-default" specifies that the default class is also mapped to this policy. !--- "fair-queue" specifies that all other traffic is served in the WFQ.


policy-map VOIP 
  class voice 
    priority 48 
  class class-default  
   fair-queue 


!--- Note: Although it is possible to queue various types of !--- real-time traffic to the priority queue, !--- Cisco recommends that you direct only voice traffic !--- to it. Real-time traffic such as video or voice !--- could introduce variations in delay. Please note voice and !--- video should not be combined in the same PVC. !--- (the priority queue is a First In First Out (FIFO) !--- queue). Voice traffic requires that delay be !--- nonvariable in order to avoid jitter. !--- Note: The sum of the values for priority and !--- bandwidth statements needs to be less !--- than or equal to 75% of the link bandwidth. !--- Otherwise service-policy cannot be !--- assigned to the link. When configuring VoIP over a !--- 64 Kbps link to support two !--- voice calls, it is common to allocate more than 75% !--- (48 Kbps) of the link bandwidth to !--- the priority queue. In such cases, you can use the !--- max-reserved-bandwidth <#%> command in order to raise !--- available bandwidth to a value more than 75%.


!
!
!
fax interface-type fax-mail
mta receive maximum-recipients 0
!
interface Loopback0
 ip address 10.1.1.2 255.255.255.0
!
!
interface FastEthernet0/0
 ip address 172.17.111.16 255.255.255.224
 duplex auto
 speed auto
!
interface Serial0/0
 no ip address
 encapsulation frame-relay IETF
 no ip route-cache
 no ip mroute-cache
 frame-relay traffic-shaping
!

!--- Choose the frame relay interface to be !--- associated with the virtual interface. The !--- virtual template could equally have been associated !--- with the physical interface. !--- The "class mlp" associates the virtual template interface !--- defined in "interface Virtual-Template1" with a Frame Relay DLCI. !--- Associates a Frame Relay map class with a DLCI.


interface Serial0/0.1 point-to-point 
 no ip route-cache
 no ip mroute-cache
 frame-relay interface-dlci 16 ppp Virtual-Template1 
  class mlp 


!--- The interface command creates a virtual !--- template called Virtual-Template1. !--- A bandwidth of 64 Kbps is assigned to this !--- template interface. This bandwidth is used !--- by Cisco IOS to calculate the data fragment size as noted regarding !--- interleaving of PPP segments. !--- "ip rtp header-compression"—cRTP is supported in an ATM/Frame Relay Interworking !--- environment. It requires Cisco IOS Software Release 12.2(2)T on the !--- ATM router. !--- "service-policy output VOIP"—The VoIP policy created earlier is assigned !--- to this interface in the outbound direction. !--- PPP multilink is enabled and the !--- maximum delay per segment is specified. This bandwidth is !--- used by Cisco IOS to calculate the data fragement size as noted. !--- Interleaving of PPP segments is enabled, which allows !--- voice packets to be expedited. Voice !--- packets need only wait behind a single segment of !--- a previously queued data packet (for example, 10 ms !--- delay) rather than wait until the end of the !--- entire data packet. Cisco IOS calculates the !--- data fragment size using the following formula: !--- fragment size = delay x bandwidth/8

!
interface Virtual-Template1 
 bandwidth 64 
 ip unnumbered loopback0
 ip rtp header-compression 
 no ip route-cache
 load-interval 30
 max-reserved-bandwidth 99
 service-policy output VOIP 
 ppp multilink 
 ppp multilink fragment-delay 10 
 ppp multilink interleave 
!


!
ip classless
ip route 0.0.0.0 0.0.0.0 172.17.111.1
no ip http server
ip pim bidir-enable
!
!
!

!--- A map class called mlp is created. !--- With "no frame-relay adaptive-shaping", adaptive !--- shaping is disabled. You do not !--- want to exceed CIR and have voice packets !--- possibly queued within the Frame Relay network. !--- Waiting for a BECN to resolve this !--- situation could result in poor voice quality. !--- The frame-relay cir 64000 command forces the router to transmit !--- at the desired CIR rate rather than line !--- rate for the port. !--- "frame-relay bc 640" configures the Bc value to force the desired !--- Tc (shaping interval) value is 10 ms. !--- This formula should be used to determine !--- the Bc value to use: Tc = Bc/CIR. A !--- smaller Tc value reduces the interval a voice !--- packet has to wait to be sent. !--- As in "frame-relay be 0", the Be value should be set to zero !--- in order to avoid voice being sent as part of a burst !--- that is not guaranteed by the Frame Relay network.


map-class frame-relay mlp

 no frame-relay adaptive-shaping
 frame-relay cir 64000  
 frame-relay bc 640 
 frame-relay be 0 


!
call rsvp-sync
!
voice-port 1/0/0
!
voice-port 1/0/1
!
!
mgcp profile default
!
dial-peer cor custom
!
!
!
dial-peer voice 123 voip
 destination-pattern 123
 session target ipv4:10.1.1.1
 ip qos dscp cs5 media
 ip qos dscp cs5 signaling
 no vad
!
dial-peer voice 456 pots
 destination-pattern 456
 port 1/0/0
!
!
line con 0
line aux 0
line vty 0 4
 exec-timeout 0 0
 password cisco
 login
!
!
end

ATM连接路由器
!--- Note: This configuration is commented only !--- where additional consideration is required from the !--- above configuration of the Frame Relay router. version 12.2 service timestamps debug datetime msec service timestamps log uptime no service password-encryption ! hostname ATM ! enable password cisco ! username FR password 0 cisco memory-size iomem 25 ip subnet-zero ! ! ! access-list 105 permit ip any any dscp ef access-list 105 permit udp any any range 16384 32767 access-list 105 permit ip any any precedence critical ! class-map match-all voice match access-group 105 ! ! !--- Note: Matching commands to the Frame Relay !--- router side of the network. ! ! policy-map VOIP class voice priority 48 class class-default fair-queue !--- Note: Matching commands to the Frame Relay !--- router side of the network. ! ! fax interface-type fax-mail mta receive maximum-recipients 0 ! controller T1 2/0 framing sf linecode ami ! ! ! ! interface ATM0/0 no ip address ip route-cache no atm ilmi-keepalive ! !--- "interface ATM0/0.1 point-to-point" chooses the ATM subinterface. !--- The physical interface could equally have been used. !--- "pvc 10/100" creates an ATM PVC. !--- "cbr 64"—A VBR PVC has been defined on this example. !--- This exapmle uses VBR non-realtime and the sustained !--- cell rate (SCR) should be equal to the peak !--- cell rate (PCR) in order to avoid bursting. !--- ATM cell tax and the possibility !--- of ATM bandwidth expansion due to poor !--- fragment/cell alignment, means that it !--- cannot be assumed that the PCR/SCR on the ATM !--- side should equal the CIR of the Frame Relay side. !--- Maintain the value of CIR on the Frame-Relay side to define !--- our SCR, in this case, 64 kbps. This value may in some networks !--- require some fine-tuning as the CIR on the Frame side does not !--- exactly match the SCR on the ATM but makes for a good-enough estimation !--- for most purposes. !--- Refer to Designing and Deploying !--- Multilink PPP over Frame Relay and ATM !--- for more information. !--- "encapsulation aal5snap" is required. !--- "protocol ppp Virtual-Template1" associates the virtual !--- template with the ATM PVC. interface ATM0/0.1 point-to-point ip route-cache pvc 10/100 cbr 64 encapsulation aal5snap protocol ppp Virtual-Template1 ! ! interface loopback0 ip address 10.1.1.1 255.255.255.0 ! interface Ethernet3/0 ip address 172.17.111.15 255.255.255.224 half-duplex ! interface Ethernet3/1 no ip address shutdown half-duplex ! interface Virtual-Template1 bandwidth 64 ip unnumbered loopback0 ip rtp header-compression no ip route-cache load-interval 30 max-reserved-bandwidth 99 service-policy output VOIP ppp multilink ppp multilink fragment-delay 10 ppp multilink interleave !--- Note: The virtual template is created in !--- exactly the same way as for the !--- Frame Relay router side of the network. !--- An additional consideration for !--- the ATM router is that the fragment size !--- should be optimized to fit into !--- an integral number of ATM cells. !--- Refer to Designing and Deploying !--- Multilink PPP over Frame Relay and ATM !--- for more information on this issue. ! ip classless ip route 0.0.0.0 0.0.0.0 172.17.111.1 ip http server ip pim bidir-enable ! ! call rsvp-sync ! voice-port 1/0/0 description FXS ! voice-port 1/0/1 ! voice-port 1/1/0 description FXO ! voice-port 1/1/1 ! ! mgcp profile default ! dial-peer cor custom ! ! ! dial-peer voice 456 voip destination-pattern 456 session target ipv4:10.1.1.2 ip qos dscp cs5 media ip qos dscp cs5 signaling no vad ! dial-peer voice 123 pots destination-pattern 123 port 1/1/0 ! ! line con 0 line aux 0 line vty 0 4 exec-timeout 0 0 password cisco login ! ! end

ATM连接路由器


!--- Note: This configuration is commented only !--- where additional consideration is required from the !--- above configuration of the Frame Relay router.


version 12.2
service timestamps debug datetime msec
service timestamps log uptime
no service password-encryption
!
hostname ATM
!
enable password cisco
!
username FR password 0 cisco
memory-size iomem 25
ip subnet-zero
!
!
!
access-list 105 permit ip any any dscp ef
access-list 105 permit udp any any  range 16384 32767
access-list 105 permit ip any any precedence critical
!
class-map match-all voice
 match access-group 105
!
!

!--- Note: Matching commands to the Frame Relay !--- router side of the network.


!
!
policy-map VOIP
  class voice
    priority 48
  class class-default
   fair-queue


!--- Note: Matching commands to the Frame Relay !--- router side of the network.


!
!
fax interface-type fax-mail
mta receive maximum-recipients 0
!
controller T1 2/0
 framing sf
 linecode ami
!
!
!
!
interface ATM0/0
 no ip address
 ip route-cache
 no atm ilmi-keepalive
!

!--- "interface ATM0/0.1 point-to-point" chooses the ATM subinterface. !--- The physical interface could equally have been used. !--- "pvc 10/100" creates an ATM PVC. !--- "cbr 64"—A VBR PVC has been defined on this example. !--- This exapmle uses VBR non-realtime and the sustained !--- cell rate (SCR) should be equal to the peak !--- cell rate (PCR) in order to avoid bursting. !--- ATM cell tax and the possibility !--- of ATM bandwidth expansion due to poor !--- fragment/cell alignment, means that it !--- cannot be assumed that the PCR/SCR on the ATM !--- side should equal the CIR of the Frame Relay side. !--- Maintain the value of CIR on the Frame-Relay side to define !--- our SCR, in this case, 64 kbps. This value may in some networks !--- require some fine-tuning as the CIR on the Frame side does not !--- exactly match the SCR on the ATM but makes for a good-enough estimation !--- for most purposes. !--- Refer to Designing and Deploying !--- Multilink PPP over Frame Relay and ATM !--- for more information. !--- "encapsulation aal5snap" is required. !--- "protocol ppp Virtual-Template1" associates the virtual !--- template with the ATM PVC.


interface ATM0/0.1 point-to-point
 ip route-cache
 pvc 10/100 
  cbr 64 
  encapsulation aal5snap 
  protocol ppp Virtual-Template1 


!
!
interface loopback0
 ip address 10.1.1.1 255.255.255.0
!
interface Ethernet3/0
 ip address 172.17.111.15 255.255.255.224
 half-duplex
!
interface Ethernet3/1
 no ip address
 shutdown
 half-duplex
!
interface Virtual-Template1
 bandwidth 64
 ip unnumbered loopback0
 ip rtp header-compression
 no ip route-cache
 load-interval 30
 max-reserved-bandwidth 99
 service-policy output VOIP
 ppp multilink
 ppp multilink fragment-delay 10
 ppp multilink interleave


!--- Note: The virtual template is created in !--- exactly the same way as for the !--- Frame Relay router side of the network. !--- An additional consideration for !--- the ATM router is that the fragment size !--- should be optimized to fit into !--- an integral number of ATM cells. !--- Refer to Designing and Deploying !--- Multilink PPP over Frame Relay and ATM !--- for more information on this issue.


!
ip classless
ip route 0.0.0.0 0.0.0.0 172.17.111.1
ip http server
ip pim bidir-enable
!
!
call rsvp-sync
!
voice-port 1/0/0
 description FXS
!
voice-port 1/0/1
!
voice-port 1/1/0
 description FXO
!
voice-port 1/1/1
!
!
mgcp profile default
!
dial-peer cor custom
!
!
!
dial-peer voice 456 voip
 destination-pattern 456
 session target ipv4:10.1.1.2
 ip qos dscp cs5 media
 ip qos dscp cs5 signaling
 no vad   
!
dial-peer voice 123 pots
 destination-pattern 123
 port 1/1/0
!
!
line con 0
line aux 0
line vty 0 4
 exec-timeout 0 0
 password cisco
 login
!
!
end

验证

使用本部分可确认配置能否正常运行。

命令输出解释程序（仅限注册用户）(OIT) 支持某些 show 命令。使用 OIT 可查看对 show 命令输出的分析。

以下show命令可用于验证ATM/帧中继互通环境的运行状态，包括DLCI和PVC统计信息、物理和虚拟接口状态、策略(QoS)应用和cRTP信息：

show ppp multilink interface interface-name — 验证捆绑是否处于up/down状态，哪个虚拟访问接口是捆绑（MLPPP捆绑），哪些是成员（PPP链路）。此命令还验证载波是否丢弃信元/帧（丢失分片<> 0）。唯一可接受的分段丢失是由循环冗余校验(CRC)错误引起的。
show user — 显示与虚拟访问接口关联的编号。您可以使用此命令或show ppp multilink命令输出中的信息，这样您便可以显示接口的统计数据或者清除接口。
show frame-relay pvc dlci — 显示流量整形参数、分段值和丢弃的数据包等信息。此命令还显示物理接口是否已绑定到虚拟接口。
show atm pvc pvc — 显示所有活动ATM PVC和流量信息。
show policy-map interface interface-name — 显示PQ中的所有LLQ操作和任何丢包。有关此命令的各个字段的详细信息，请参阅show policy-map interface命令输出中的“了解数据包计数器”。

注意：花式队列始终应用于virtual-access2接口。其他接口使用FIFO队列。
show ip rtp header-compression — 显示RTP报头压缩统计信息（如果已配置）。请注意，统计信息已附加到虚拟访问2接口，即捆绑接口。

以下是这些命令的示例：

FR#show ppp multilink interface virtual-access 2
Virtual-Access2, bundle name is ATM
Bundle up for 00:22:42
0 lost fragments, 0 reordered, 0 unassigned
0 discarded, 0 lost received, 231/255 load
0x2E5 received sequence, 0x10C31 sent sequence
Member links: 1 (max not set, min not set)
Virtual-Access1, since 00:22:42, last rcvd seq 0002E4 160 weight

此输出显示了帧中继路由器上的show users。

FR#show users
Line User Host(s) Idle Location
67 vty 1 idle 00:00:00 10.1.1.1
Interface User Mode Idle Peer Address
Vi1 Virtual PPP (FR ) - 
Vi2 Virtual PPP (Bundle) 00:00:00 10.1.1.1
FR#

此输出显示ATM路由器上的show users。

ATM#show users 
Line User Host(s) Idle Location
131 vty 1 idle 00:00:00 64.104.207.95
Interface User Mode Idle Peer Address
Vi1 Virtual PPP (ATM ) - 
Vi2 Virtual PPP (Bundle) 00:00:02 10.1.1.2
ATM#

此输出显示show frame-relay pvc命令。

FR#show frame-relay pvc 16
 PVC Statistics for interface Serial0/0 (Frame Relay DTE)
 DLCI = 16, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0.1
  
     input pkts 2301 output pkts 2295 in bytes 152266 
     out bytes 151891 dropped pkts 0 in FECN pkts 0 
     in BECN pkts 0 out FECN pkts 0 out BECN pkts 0 
     in DE pkts 0 out DE pkts 0 
     out bcast pkts 0 out bcast bytes 0 
     5 minute input rate 9000 bits/sec, 9 packets/sec
     5 minute output rate 9000 bits/sec, 9 packets/sec
     pvc create time 23:46:56, last time pvc status changed 00:22:56
     Bound to Virtual-Access1 (up, cloned from Virtual-Template1) 
     
!--- PPP link interface.

     cir 64000 bc 640 be 0 byte limit 80 interval 10 
     mincir 64000 byte increment 80 Adaptive Shaping none
     pkts 2296 bytes 152053 pkts delayed 9 bytes delayed 375
     shaping active 
     traffic shaping drops 0
     Queueing strategy: fifo
     Output queue 0/40, 0 drop, 0 dequeued
FR#

此输出显示ATM路由器上的show atm pvc 10/100命令。

ATM#show atm pvc 10/100 
     ATM0/0.1: VCD: 1, VPI: 10, VCI: 100
     CBR, SusRate: 128
     AAL5-LLC/SNAP, etype:0x0, Flags: 0x820, VCmode: 0x0
     OAM frequency: 0 second(s), OAM retry frequency: 1 second(s)
     OAM up retry count: 3, OAM down retry count: 5
     OAM Loopback status: OAM Disabled
     OAM VC state: Not Managed
     ILMI VC state: Not Managed
     InARP frequency: 15 minutes(s)
     Transmit priority 1
     InPkts: 729, OutPkts: 729, InBytes: 49700, OutBytes: 51158
     InPRoc: 0, OutPRoc: 729
     InFast: 729, OutFast: 0, InAS: 0, OutAS: 0
     InPktDrops: 0, OutPktDrops: 0/0/0 (holdq/outputq/total)
     CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0, 
     CPIErrors: 0
     OAM cells received: 0
     F5 InEndloop: 0, F5 InSegloop: 0, F5 InAIS: 0, F5 InRDI: 0
     F4 InEndloop: 0, F4 InSegloop: 0, F4 InAIS: 0, F4 InRDI: 0
     OAM cells sent: 0
     F5 OutEndloop: 0, F5 OutSegloop: 0, F5 OutRDI: 0
     F4 OutEndloop: 0, F4 OutSegloop: 0, F4 OutRDI: 0
     OAM cell drops: 0
     Status: UP
   PPP: Virtual-Access2 from Virtual-Template1 
    
!--- MLPPP bundle interface.

ATM#

这是帧中继路由器上的show policy-map。

FR#show policy-map interface Virtual-Access2
Service-policy output: VoIP
Class-map: voice (match-all)
15483 packets, 959502 bytes
30 second offered rate 24000 bps, drop rate 0 bps
Match: ip dscp 40 
Weighted Fair Queueing 
Strict Priority 

!--- LLQ Strict Priority Queue for voice.

Output Queue: Conversation 24 
Bandwidth 48(kbps) Burst 1500 (Bytes)
(pkts matched/bytes matched) 15536/962784
(total drops/bytes drops) 0/0 

!--- No drops in the voice queue.

Class-map: class-default (match-any)
139 packets, 19481 bytes
30 second offered rate 1000 bps, drop rate 0 bps
Match: any 
Weighted Fair Queueing
Flow Based Fair Queueing
Maximum Number of Hashed Queues 16 
(total queued/total drops/no-buffer drops) 0/0/0

此输出显示ATM路由器上的show policy map命令。

ATM#show policy-map interface Virtual-Access2 
Service-policy output: VOIP
Class-map: voice (match-all)
11293 packets, 699718 bytes
30 second offered rate 24000 bps, drop rate 0 bps
Match: ip dscp 40 
Weighted Fair Queueing
Strict Priority 

!--- LLQ Strict Priority Queue for voice.

Output Queue: Conversation 24 
Bandwidth 48 (kbps) Burst 1500 (Bytes)
(pkts matched/bytes matched) 11352/703376
(total drops/bytes drops) 0/0 

!--- No drops in the voice queue.

Class-map: class-default (match-any)
63 packets, 9772 bytes
30 second offered rate 0 bps, drop rate 0 bps
Match: any 
Weighted Fair Queueing
Flow Based Fair Queueing
Maximum Number of Hashed Queues 16 
(total queued/total drops/no-buffer drops) 0/0/0
ATM#

此输出显示了帧中继路由器上的show ip rtp header-compression命令。

FR#show ip rtp header-compression
RTP/UDP/IP header compression statistics:
Interface Virtual-Access1:
Rcvd: 0 total, 0 compressed, 0 errors
0 dropped, 0 buffer copies, 0 buffer failures
Sent: 0 total, 0 compressed,
0 bytes saved, 0 bytes sent
Connect: 16 rx slots, 16 tx slots,
0 long searches, 0 misses 0 collisions

Interface Virtual-Template1:
Rcvd: 0 total, 0 compressed, 0 errors
0 dropped, 0 buffer copies, 0 buffer failures
Sent: 0 total, 0 compressed,
0 bytes saved, 0 bytes sent
Connect: 16 rx slots, 16 tx slots,
0 long searches, 0 misses 0 collisions

Interface Virtual-Access2:
Rcvd: 23682 total, 23681 compressed, 0 errors
0 dropped, 0 buffer copies, 0 buffer failures
Sent: 327 total, 233 compressed,
8821 bytes saved, 5159 bytes sent
2.70 efficiency improvement factor
Connect: 16 rx slots, 16 tx slots,
0 long searches, 94 misses 0 collisions
71% hit ratio, five minute miss rate 0 misses/sec, 0 max

此输出显示ATM路由器上的show ip rtp header-compression命令。

ATM#show ip rtp header-compression
RTP/UDP/IP header compression statistics:
Interface Virtual-Access1:
Rcvd: 0 total, 0 compressed, 0 errors
0 dropped, 0 buffer copies, 0 buffer failures
Sent: 0 total, 0 compressed,
0 bytes saved, 0 bytes sent
Connect: 16 rx slots, 16 tx slots,
0 long searches, 0 misses 0 collisions, 0 negative cache hits

Interface Virtual-Template1:
Rcvd: 0 total, 0 compressed, 0 errors
0 dropped, 0 buffer copies, 0 buffer failures
Sent: 0 total, 0 compressed,
0 bytes saved, 0 bytes sent
Connect: 16 rx slots, 16 tx slots,
0 long searches, 0 misses 0 collisions, 0 negative cache hits

Interface Virtual-Access2:
Rcvd: 283 total, 233 compressed, 0 errors
0 dropped, 0 buffer copies, 0 buffer failures
Sent: 25341 total, 25340 compressed,
955537 bytes saved, 564463 bytes sent
2.69 efficiency improvement factor
Connect: 16 rx slots, 16 tx slots,
0 long searches, 1 misses 0 collisions, 100 negative cache hits
99% hit ratio, five minute miss rate 0 misses/sec, 0 max

故障排除

使用本部分可排除配置的故障。

此部分提供部分澄清MLP LFI的示例调试，它同时充当您排除配置故障的操作示例。

故障排除命令

命令输出解释程序（仅限注册用户）(OIT) 支持某些 show 命令。使用 OIT 可查看对 show 命令输出的分析。

注意：在使用debug命令之前，请参阅有关Debug命令的重要信息。

debug ppp negotiation — 说明克隆两个虚拟访问接口以表示PPP和PPP捆绑链路的过程。虚拟访问接口1 (Vi1)是的PPP链路，其中绑定了PVC (ATM或帧)。虚拟接口2(Vi2)是连接排队策略的PPP捆绑链路。
debug ppp multilink fragment — 说明大数据包与小语音数据包交错的概念。交叉发生在Vi2接口(MLP级别)，因为捆绑接口被分配了的理想的排队。

这是debug ppp negotiation命令的命令输出。

FR(config-if)#no shut
FR(config-if)#^Z
FR#
FR#
6d23h: %LINK-3-UPDOWN: Interface Virtual-Access1, changed state to up
*Mar 7 23:20:42.842: Vi1 PPP: Treating connection as 
a dedicated line 

!--- Vi1 is the PPP link to which the PVC is bound.

*Mar 7 23:20:42.842: Vi1 PPP: Phase is ESTABLISHING, Active Open
*Mar 7 23:20:42.842: Vi1 LCP: O CONFREQ [Closed] id 197 len 19
*Mar 7 23:20:42.842: Vi1 LCP: MagicNumber 0xF44128D2 (0x0506F44128D2)
*Mar 7 23:20:42.842: Vi1 LCP: MRRU 1524 (0x110405F4)
*Mar 7 23:20:42.842: Vi1 LCP: EndpointDisc 1 FR (0x1305014652) 

!--- Router FR at one end of PPP discovery.

*Mar 7 23:20:42.858: Vi1 LCP: I CONFREQ [REQsent] id 14 len 20
*Mar 7 23:20:42.858: Vi1 LCP: MagicNumber 0x294819D4 (0x0506294819D4)
*Mar 7 23:20:42.858: Vi1 LCP: MRRU 1524 (0x110405F4)
*Mar 7 23:20:42.858: Vi1 LCP: EndpointDisc 1 ATM (0x13060141544D) 

!--- Router ATM at the other end of PPP discovery.

*Mar 7 23:20:42.858: Vi1 LCP: O CONFACK [REQsent] id 14 len 20

*Mar 7 23:20:42.862: Vi1 LCP: MagicNumber 0x294819D4 (0x0506294819D4)
*Mar 7 23:20:42.862: Vi1 LCP: MRRU 1524 (0x110405F4)
*Mar 7 23:20:42.862: Vi1 LCP: EndpointDisc 1 ATM (0x13060141544D)
*Mar 7 23:20:42.870: Vi1 LCP: I CONFACK [ACKsent] id 197 len 19
*Mar 7 23:20:42.870: Vi1 LCP: MagicNumber 0xF44128D2 (0x0506F44128D2)
*Mar 7 23:20:42.870: Vi1 LCP: MRRU 1524 (0x110405F4)
*Mar 7 23:20:42.870: Vi1 LCP: EndpointDisc 1 FR (0x1305014652)
*Mar 7 23:20:42.870: Vi1 LCP: State is Open
*Mar 7 23:20:42.870: Vi1 PPP: Phase is FORWARDING, Attempting Forward
*Mar 7 23:20:42.874: Vi1 PPP: Phase is ESTABLISHING, Finish LCP
*Mar 7 23:20:42.874: Vi1 PPP: Phase is VIRTUALIZED
*Mar 7 23:20:42.942: Vi2 PPP: Phase is DOWN, Setup
*Mar 7 23:20:43.222: Vi1 IPCP: Packet buffered while building MLP bundle interface
6d23h: %LINK-3-UPDOWN: Interface Virtual-Access2, changed state to up 

!--- MLP level queuing.

*Mar 7 23:20:43.226: Vi2 PPP: Treating connection as a dedicated line
*Mar 7 23:20:43.226: Vi2 PPP: Phase is ESTABLISHING, Active Open
*Mar 7 23:20:43.226: Vi2 LCP: O CONFREQ [Closed] id 1 len 19
*Mar 7 23:20:43.226: Vi2 LCP: MagicNumber 0xF4412A53 (0x0506F4412A53)
*Mar 7 23:20:43.226: Vi2 LCP: MRRU 1524 (0x110405F4)
*Mar 7 23:20:43.230: Vi2 LCP: EndpointDisc 1 FR (0x1305014652)
*Mar 7 23:20:43.230: Vi2 MLP: 
Added first link Vi1 to bundle ATM 

!--- PVCs make up the bundle.

*Mar 7 23:20:43.230: Vi2 PPP: Phase is UP
*Mar 7 23:20:43.230: Vi2 IPCP: O CONFREQ [Closed] id 1 len 10
*Mar 7 23:20:43.234: Vi2 IPCP: Address 10.1.1.2 (0x03060A010102)
*Mar 7 23:20:43.234: Vi2 PPP: Pending ncpQ size is 1
*Mar 7 23:20:43.234: Vi1 IPCP: Redirect packet to Vi1
*Mar 7 23:20:43.234: Vi2 IPCP: I CONFREQ [REQsent] id 1 len 10
*Mar 7 23:20:43.234: Vi2 IPCP: Address 10.1.1.1 (0x03060A010101)
*Mar 7 23:20:43.234: Vi2 IPCP: O CONFACK [REQsent] id 1 len 10
*Mar 7 23:20:43.234: Vi2 IPCP: Address 10.1.1.1 (0x03060A010101)
*Mar 7 23:20:43.266: Vi2 IPCP: I CONFACK [ACKsent] id 1 len 10
*Mar 7 23:20:43.266: Vi2 IPCP: Address 10.1.1.2 (0x03060A010102)
*Mar 7 23:20:43.266: Vi2 IPCP: State is Open
*Mar 7 23:20:43.266: Vi2 IPCP: Install route to 10.1.1.1
*Mar 7 23:20:43.270: Vi2 IPCP: Add link info for cef entry 10.1.1.1

此命令输出来自debug ppp multilink fragment命令。

*Mar 7 23:16:08.034: Vi2 MLP: 
Packet interleaved from queue 24
*Mar 7 23:16:08.038: Vi1 MLP: O ppp UNKNOWN(0x0000) (0000) size 64 
*Mar 7 23:16:08.038: Vi2 MLP: Packet interleaved from queue 24
*Mar 7 23:16:08.038: Vi1 MLP: O ppp UNKNOWN(0x0000) (0000) size 64 
*Mar 7 23:16:08.038: Vi2 MLP: Packet interleaved from queue 24
*Mar 7 23:16:08.038: Vi1 MLP: O ppp UNKNOWN(0x0000) (0000) size 64 
*Mar 7 23:16:08.038: Vi1 MLP: O frag 0000829B size 160 
*Mar 7 23:16:08.042: Vi1 MLP: I ppp IP (0021) size 64 direct
*Mar 7 23:16:08.046: Vi1 MLP: I ppp IP (0021) size 64 direct