Frame Relay OSI Frame Relay Application Presentation Session

Frame Relay 堆疊 OSI 參考模型 Frame Relay Application Presentation Session Transport Network IP/IPX/Apple. Talk, etc. Data Link Frame Relay Physical EIA/TIA-232, EIA/TIA-449, V. 35, X. 21, EIA/TIA-530 6

Frame Relay 術語 PVC DLCI: 100 DLCI: 200 LMI 100=Active 400=Active DLCI: 400 Local Access Loop=64 kbps Local Access Loop=T 1 PVC DLCI: 500 Local Access Loop=64 kbps 7

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Frame Relay 頻寬與流量控制 ● ● Frame Relay 為共享網路，但欲達類似電路交 換之服務，需管制頻寬之使用 技術上定義了以下相關術語： – 承諾資訊速率(Committed information rate, CIR) – 超額資訊速率(Excess information rate, EIR) – 適合丟棄的(Discard eligible, DE) – 明顯的擁塞通知(Explicit congestion notification, ECN) (參考Cisco CCNA 教材 5. 1. 4 節 頁籤[4]) ● ● 正向(Forward) ECN (FECN) 反向(Backward) ECN (BECN) 20

節制範例 • • 埠速率： 64 Kbps Committed Time (Tc): 0. 5 seconds CIR: 12800 bps 計算得 Committed Burst (Bc) = CIR Tc: 6400 bits • 為了方便，假設封包大小正好都是 6400 bits 超過，標上DE 21

Frame Relay 位址映射 DLCI: 500 PVC 10. 1. 1. 1 CSU/DSU Inverse ARP 或 Frame Relay map Frame Relay DLCI (500) IP (10. 1. 1. 1) – 從提供商那裏得到本地的DLCI號 – 建立目的地址和本地DLCI之間的映射關係 23

Frame Relay 訊令 DLCI: 500 PVC 10. 1. 1. 1 CSU/DSU LMI 500=Active 400=Inactive DLCI: 400 x PVC Keepalive • Cisco 路由器支援三種 LMI 標準: – Cisco – ANSI T 1. 617 Annex D – ITU-T Q. 933 Annex A 25

Frame Relay 的反轉 ARP 協 定和 LMI 作 1 DLCI=100 Frame Relay Cloud 172. 168. 5. 5 ● 參考Cisco CCNA 4 5. 1. 7節 動畫 DLCI=400 172. 168. 5. 7 26

Frame Relay 的反轉 ARP 協 定和 LMI 作 1 DLCI=100 172. 168. 5. 5 2 Status Inquiry Frame Relay Cloud DLCI=400 172. 168. 5. 7 Status Inquiry 2 27

Frame Relay 的反轉 ARP 協 定和 LMI 作 1 Frame Relay Cloud DLCI=100 DLCI=400 172. 168. 5. 5 172. 168. 5. 7 2 Status Inquiry Local DLCI 100=Active Status Inquiry 3 34 2 Local DLCI 400=Active 28

Frame Relay 的反轉 ARP 協 定和 LMI 作 1 Frame Relay Cloud DLCI=100 DLCI=400 172. 168. 5. 5 172. 168. 5. 7 2 Status Inquiry Local DLCI 100=Active 4 Status Inquiry 3 34 2 Local DLCI 400=Active Hello, I am 172. 168. 5. 5. 29

Frame Relay 的反轉 ARP 協 定和 LMI 作 DLCI=100 Frame Relay Cloud DLCI=400 172. 168. 5. 7 172. 168. 5. 5 Frame Relay Map 172. 168. 5. 5 DLCI 400 Active Hello, I am 172. 168. 5. 7. 5 5 4 Frame Relay Map 172. 168. 5. 7 DLCI 100 Active 30

Frame Relay 的反轉 ARP 協 定和 LMI 作 DLCI=100 Frame Relay Cloud DLCI=400 172. 168. 5. 7 172. 168. 5. 5 Frame Relay Map 172. 168. 5. 5 DLCI 400 Active Hello, I am 172. 168. 5. 7. 5 5 4 Frame Relay Map 172. 168. 5. 7 DLCI 100 Active 6 Hello, I am 172. 168. 5. 5. 31

Frame Relay 的反轉 ARP 協 定和 LMI 作 DLCI=100 Frame Relay Cloud DLCI=400 172. 168. 5. 7 172. 168. 5. 5 Frame Relay Map 172. 168. 5. 5 DLCI 400 Active Hello, I am 172. 168. 5. 7. 5 5 4 Frame Relay Map 172. 168. 5. 7 DLCI 100 Active 6 Hello, I am 172. 168. 5. 5. 7 Keepalives 7 32

設定 Frame Relay Rel. 11. 2 Router HQ interface Serial 1 ip address 10. 16. 0. 1 255. 0 encapsulation frame-relay bandwidth 64 Rel. 10. 3 Router Branch interface Serial 1 ip address 10. 16. 0. 2 255. 0 encapsulation frame-relay bandwidth 64 frame-relay lmi-type ansi 命令格式 (config-if)# encapsulation frame-relay [cisco | ietf] 33

設定 Frame Relay Rel. 11. 2 Router Rel. 10. 3 Router Branch HQ interface Serial 1 ip address 10. 16. 0. 1 255. 0 encapsulation frame-relay bandwidth 64 interface Serial 1 ip address 10. 16. 0. 2 255. 0 encapsulation frame-relay bandwidth 64 frame-relay lmi-type ansi 反轉 ARP • 預設情況下是啟動的 • 在配置輸出資訊中看不出來 34

設定靜態的 Frame Relay 映射 DLCI=110 IP address=10. 16. 0. 1/24 p 1 r 1 HQ Branch DLCI=100 IP address=10. 16. 0. 2/24 interface Serial 1 ip address 10. 16. 0. 1 255. 0 encapsulation frame-relay bandwidth 64 frame-relay map ip 10. 16. 0. 2 110 broadcast 用於當遠端路由器不支援 Inverse ARP 時 或當必須控制PVC上的廣播或群播交通時(用broadcast選項) 35

查看 Frame Relay 訊息 Router#show interface s 0 Serial 0 is up, line protocol is up Hardware is HD 64570 Internet address is 10. 140. 1. 2/24 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation FRAME-RELAY, loopback not set, keepalive set (10 sec) LMI enq sent 19, LMI stat recvd 20, LMI upd recvd 0, DTE LMI up LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0 LMI DLCI 1023 LMI type is CISCO frame relay DTE FR SVC disabled, LAPF state down Broadcast queue 0/64, broadcasts sent/dropped 8/0, interface broadcasts 5 Last input 00: 00: 02, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops <Output omitted> 顯示協定、DLCI、和 LMI 的相關資訊 36

查看 Frame Relay 訊息 Router#show frame-relay lmi LMI Statistics for interface Serial 0 (Frame Relay DTE) LMI TYPE = CISCO Invalid Unnumbered info 0 Invalid Prot Disc 0 Invalid dummy Call Ref 0 Invalid Msg Type 0 Invalid Status Message 0 Invalid Lock Shift 0 Invalid Information ID 0 Invalid Report IE Len 0 Invalid Report Request 0 Invalid Keep IE Len 0 Num Status Enq. Sent 113100 Num Status msgs Rcvd 113100 Num Update Status Rcvd 0 Num Status Timeouts 0 顯示 LMI 資訊 37

查看 Frame Relay 訊息 Router#show frame-relay pvc 100 PVC Statistics for interface Serial 0 (Frame Relay DTE) DLCI = 100, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial 0 input pkts 28 output pkts 10 in bytes 8398 out bytes 1198 dropped pkts 0 in FECN pkts 0 in BECN pkts 0 out FECN pkts 0 out BECN pkts 0 in DE pkts 0 out bcast pkts 10 out bcast bytes 1198 pvc create time 00: 03: 46, last time pvc status changed 00: 03: 47 顯示 PVC 資料通訊資訊 38

查看 Frame Relay 訊息 Router#show frame-relay map Serial 0 (up): ip 10. 140. 1. 1 dlci 100(0 x 64, 0 x 1840), dynamic, broadcast, , status defined, active 顯示路由資訊 39

查看 Frame Relay 訊息 Router#show frame-relay map Serial 0 (up): ip 10. 140. 1. 1 dlci 100(0 x 64, 0 x 1840), dynamic, broadcast, , status defined, active Router#clear frame-relay-inarp Router#sh frame map Router# 清除動態的Frame Relay 映射關係 40

查看 Frame Relay 訊息 Router#debug Frame lmi Frame Relay LMI debugging is on Displaying all Frame Relay LMI data Router# 1 w 2 d: Serial 0(out): St. Enq, myseq 140, yourseen 139, DTE up 1 w 2 d: datagramstart = 0 x. E 008 EC, datagramsize = 13 1 w 2 d: FR encap = 0 x. FCF 10309 1 w 2 d: 00 75 01 01 01 03 02 8 C 8 B 1 w 2 d: Serial 0(in): Status, myseq 140 1 w 2 d: RT IE 1, length 1, type 1 1 w 2 d: KA IE 3, length 2, yourseq 140, myseq 140 1 w 2 d: Serial 0(out): St. Enq, myseq 141, yourseen 140, DTE up 1 w 2 d: datagramstart = 0 x. E 008 EC, datagramsize = 13 1 w 2 d: FR encap = 0 x. FCF 10309 1 w 2 d: 00 75 01 01 01 03 02 8 D 8 C 1 w 2 d: Serial 0(in): Status, myseq 142 1 w 2 d: RT IE 1, length 1, type 0 1 w 2 d: KA IE 3, length 2, yourseq 142, myseq 142 1 w 2 d: PVC IE 0 x 7 , length 0 x 6 , dlci 100, status 0 x 2 , bw 0 顯示 LMI 的調試資訊 41

選擇 Frame Relay 拓撲結構 Full Mesh Partial Mesh Star (Hub and Spoke) Frame Relay default: nonbroadcast, multiaccess (NMBA) 42

配置點到點的子埠 10. 17. 0. 1 s 0. 2 A DLCI=110 DL s 0. 3 0 CI 10. 18. 0. 1 = B 12 interface Serial 0 no ip address encapsulation frame-relay ! interface Serial 0. 2 point-to-point ip address 10. 17. 0. 1 255. 0 ? bandwidth 64 frame-relay interface-dlci 110 ! interface Serial 0. 3 point-to-point ip address 10. 18. 0. 1 255. 0 ? bandwidth 64 frame-relay interface-dlci 120 ! 10. 17. 0. 2 10. 18. 0. 2 C frame-relay interface-dlci 命令 用於配置子介面上的本地 DLCI *LMI不懂子介面 46

多點子埠配置舉例 s 2. 2=10. 17. 0. 1/24 20 1 = I C DL DLCI=130 RTR 1 B s 2. 1=10. 17. 0. 2/24 RTR 3 DLCI= 140 interface Serial 2 no ip address encapsulation frame-relay ! interface Serial 2. 2 multipoint ip address 10. 17. 0. 1 255. 0 ? bandwidth 64 frame-relay map ip 10. 17. 0. 2 120 broadcast frame-relay map ip 10. 17. 0. 3 130 broadcast frame-relay map ip 10. 17. 0. 4 140 broadcast s 2. 1=10. 17. 0. 3/24 RTR 4 s 2. 1=10. 17. 0. 4/24 47