帧中继 Frame Relay 厦 Cisco.com 深圳职业技术学院计算机系网络专业 006,Shenzhen Polytechnic.All rightsreserved
© 2006, Shenzhen Polytechnic. All rights reserved. 1 帧中继 Frame Relay 深圳职业技术学院计算机系网络专业
教学目标（Objectives) TW Cisco.com 1.帧中继概念(Frame Relay Concept 2.帧中继术语(Frame Relay Terminology ) 3.帧中继地址映射(Frame Relay Address Mapping 4.LMI操作（LMI Operation) 5.帧中继反向ARP（Frame Relay Inverse ARP) 6.配置基本的帧中继(Configuring Basic Frame Relay 7.配置帧中继子接口(Configuring Frame Relay Subinterfaces
© 2006, Shenzhen Polytechnic. All rights reserved. 2 教学目标（ Objectives ） 1. 帧中继概念（Frame Relay Concept ） 2.帧中继术语（ Frame Relay Terminology ） 3.帧中继地址映射（Frame Relay Address Mapping ） 4.LMI操作（ LMI Operation） 5.帧中继反向ARP（ Frame Relay Inverse ARP ） 6. 配置基本的帧中继（ Configuring Basic Frame Relay ） 7.配置帧中继子接口（ Configuring Frame Relay Subinterfaces ）
帧中继预览 (Frame Relay Overview) IIE Cisco.com DCE or Frame Relay Switch CSU/DSU 帧中继工作在这里 Frame Relay works here. 帧中继用虚电路为面向连接的服务建立连接 Virtual circuits make connections for Connection- oriented service
© 2006, Shenzhen Polytechnic. All rights reserved. 3 帧中继预览 （Frame Relay Overview） 帧中继用虚电路为面向连接的服务建立连接 Virtual circuits make connections for Connectionoriented service 帧中继工作在这里 Frame Relay works here. DCE or Frame Relay Switch CSU/DSU
帧中继协议族（Frame Relay Stack) Cisco.com OSI Reference Model Frame Relay Application Presentation Session Transport Network IP/IPX/AppleTalk,etc Data Link Frame Relay EIA/TIA-232. Physical EIA/T1A-449,V.35, X.21,E1AWT1A-530 帧中继工作在OS参考模型的物理层和数据链路层 Frame Relay operate physical and datalink layer. 2006,ShenzhenPolytechnic.Allrightsreserved
© 2006, Shenzhen Polytechnic. All rights reserved. 4 帧中继协议族（Frame Relay Stack） OSI Reference Model Frame Relay Physical Presentation Session Transport Network Data Link Application EIA/TIA-232, EIA/TIA-449, V.35, X.21, EIA/TIA-530 Frame Relay IP/IPX/AppleTalk, etc. 帧中继工作在OSI参考模型的物理层和数据链路层 Frame Relay operate physical and datalink layer
帧中继术语(Frame Relay Terminology) WWWI Cisco.com PVC DLCI:100 LMI DLCI:200 100=Active 400=Active DLCI:400 -Local Access Local Loop=64 kbps Access Loop=T1 PVC _Local Access DLCI:500 Loop=64 kbps 2006.Shenzhen Polytechnic.All rights re
© 2006, Shenzhen Polytechnic. All rights reserved. 5 帧中继术语（Frame Relay Terminology） Local Access Loop=T1 Local Access Loop=64 kbps Local Access Loop=64 kbps DLCI: 400 PVC DLCI: 500 LMI 100=Active 400=Active DLCI: 200 DLCI: 100 PVC
帧中继术语(Frame Relay Terminology) AIWEEW Cisco.com 1.访问速率(Access rate):连接本地环到帧中继的端口速度。 The clock speed(port speed)of the connection(local loop)to the Frame Relay cloud. 2.数据链路连接标识(DLC)：在源和目的设备之间标识逻辑电路的 一个数值。 A number that identifies the end point in a Frame Relay network. 子套灌管暖擴骨议器艺品醒接聲裔 和帧中继交换机之间的信 A signaling standard between the customer premises equipment(CPE)device and the Frame Relay switch that is responsible for managing the connection and maintaining status between the devices 4.承诺信息速率(CIR)：ISP提供的有保障的速率。 The guaranteed rate,in bits per second,which the service provider commits to providing
© 2006, Shenzhen Polytechnic. All rights reserved. 6 帧中继术语（Frame Relay Terminology） 1.访问速率（Access rate ）：连接本地环到帧中继的端口速度。 The clock speed (port speed) of the connection (local loop) to the Frame Relay cloud. 2.数据链路连接标识（DLCI）：在源和目的设备之间标识逻辑电路的 一个数值。 A number that identifies the end point in a Frame Relay network. 3.本地管理接口（LMI）；是客户前端设备和帧中继交换机之间的信 令标准，负责管理设备之间的连接、维护设备之间的连接状态。 A signaling standard between the customer premises equipment (CPE) device and the Frame Relay switch that is responsible for managing the connection and maintaining status between the devices 4.承诺信息速率（CIR）：ISP提供的有保障的速率。 The guaranteed rate, in bits per second, which the service provider commits to providing
帧中继术语(Frame Relay Terminology) wm厦 Cisco.com 5.前向显示拥塞通知(FECN):当网络发生拥塞的时候，向目的设 备发送一个FECN数据包，来通知拥塞。 A bit set in a frame that notifies a DTE that congestion avoidance procedures should be initiated by the sending device 6后向显示拥塞通知(BECN):当网络发生拥塞的时候，.向源路由 器发送一个BECN数据包，来通知拥塞。同时按25%的比例降低数据 报发送速率。 A bit set in a frame that notifies a DTE that congestion avoidance procedures should be initiated by the sending device.If the router receives any BECNs during the current time interval,it decreases the transmit rate by 25%. 7.允许丢弃指示器(DE):,当路由器检测到拥塞时，帧中继交换机将 会首先丢弃那些DE位设置为1的数据包。 A set bit that indicates the frame may be discarded in preference to other frames if congestion occurs. 2006,Shenzhen Polytechnic.All rights reserved
© 2006, Shenzhen Polytechnic. All rights reserved. 7 帧中继术语（Frame Relay Terminology） 5.前向显示拥塞通知（FECN）：当网络发生拥塞的时候，向目的设 备发送一个FECN数据包，来通知拥塞。 A bit set in a frame that notifies a DTE that congestion avoidance procedures should be initiated by the sending device 6.后向显示拥塞通知（BECN）：当网络发生拥塞的时候，向源路由 器发送一个BECN数据包，来通知拥塞。同时按25%的比例降低数据 报发送速率。 A bit set in a frame that notifies a DTE that congestion avoidance procedures should be initiated by the sending device. If the router receives any BECNs during the current time interval, it decreases the transmit rate by 25%. 7.允许丢弃指示器（DE）：当路由器检测到拥塞时，帧中继交换机将 会首先丢弃那些DE位设置为1的数据包。 A set bit that indicates the frame may be discarded in preference to other frames if congestion occurs
帧中继地址映射 (Frame Relay Address Mapping) IWIW Cisco.com DLCI:500 PVC 10.1.1.1 CSU/DSU Inverse ARP or Frame Relay map Frame DLCI(500) P Relay (10.1.1.1) ·从ISP获得本地意义的DLCI号码 Get locally significant DLCIs from provider ·把网络地址映射到DLC! 2006.shonahonPayteMap.your network addresses to DLCIs
© 2006, Shenzhen Polytechnic. All rights reserved. 8 CSU/DSU 帧中继地址映射 （Frame Relay Address Mapping） • 从ISP获得本地意义的DLCI号码 • Get locally significant DLCIs from provider • 把网络地址映射到DLCI • Map your network addresses to DLCIs DLCI: 500 PVC 10.1.1.1 Inverse ARP or Frame Relay map IP (10.1.1.1) Frame Relay DLCI (500)
LMI类型（LMI TYPES) AIEE Cisco.com DLCI:500 PVC 10.1.1.1 CSU/DSU LMI 500=Active DLCI:400 400=Inactive Keepalive Cisco支持三种类型的LMI标准 Cisco supports three LMI standards: ·Cisco(默认) ·ANSI 。Q.933 *在路由器上配置的LM类型必须和SP提供的匹配。 *LMI type configured on the router must match the type used by the service provider
© 2006, Shenzhen Polytechnic. All rights reserved. 9 LMI类型（LMI TYPES） Cisco 支持三种类型的LMI标准 Cisco supports three LMI standards: • Cisco（默认） • ANSI • Q.933 *在路由器上配置的LMI类型必须和SP提供的匹配。 *LMI type configured on the router must match the type used by the service provider. DLCI: 400 PVC Keepalive CSU/DSU DLCI: 500 PVC 10.1.1.1 x LMI 500=Active 400=Inactive
帧中继反向ARP (Frame Relay Inverse ARP) Cisco.com 1 Frame Relay DLCI=100 Cloud 之 DLc牛400≤ 172.168.5.5 172.168.5.7 2006,Shenzhen Polytechnic.All rights reserved. 10
© 2006, Shenzhen Polytechnic. All rights reserved. 10 帧中继反向ARP （Frame Relay Inverse ARP） Frame Relay Cloud 1 DLCI=100 DLCI=400 172.168.5.5 172.168.5.7