Frame Relay switch configuration

A frame relay switch is a useful device, either in the lab or elsewhere. Like the boot register, the setting of the frame relay switch is also very profound in the router settings. You can build many different network models by learning how to configure a frame relay switch. As we are a "service provider", we must be able to independently allocate the full-induced DLCI with M & T or MCI. By establishing a precise network model in the lab, you can not only increase the confidence of the installation network, but also reduce the probability of configuration errors or device problems. This section focuses on how to configure a Cisco router to a frame relay switch. In essence, Frame Relay switching technology is a frame switching technology based on the data link connection identifier (DLCI. In the router's frame relay ARP table, the DLCI number is associated with the interface. Frame Relay uses its ARP table to check the pairing between the DLCI and the interface to determine whether to send the data frame from a specific interface. The frame relay switch is first a DCE device, that is:
· Any model of vro requires at least three Routers: one for the master node of the switch and the other two for intercommunication.
· The DCE cable is required for the serial interface of the frame switch.
Here, you need to define some frequently-used terms for Frame Relay:
· Permanent virtual circuit (PVC) 1-an end-to-end Permanent Logical circuit Used for frame transmission. The PVC endpoint is addressing with DLCI.
· Data-Link connectionidention the Data Link connection identifier (DLCI) refers to a logical number used to identify the p v c between the CPE and the frame relay switch, it ranges from 16 to 1007. In most cases, DLCI only makes sense locally, that is, only local devices know what DLCI means. For the same central site, two remote PVCs may have the same DLCI number.
· Local Management interface (LMS) refers to the signaling standard between the router and the frame relay switch. The vswitch uses LMS to determine which DLCI has been defined and their current status. MTS also supports the keephve mechanism every 10 seconds to confirm whether the PVC is activated or whether data is being exchanged. Cisco routers support three types of LMS: Cisco, ansi, and q933a. A vrolmi can use white-dynamic negotiation to determine the type of LMS for communication: --- Cisco is an LMS type defined by three major network giants: Cisco, digital, and NonhemTclecom, the default type after automatic negotiation fails. The status information is sent through DLCI1023.
-- A11si is an LCM type defined by the T1.617 standard, which is commonly referred to as appendix D by ANSI. This is the most common type in all Frame Relay networks, and its LMS status information is sent through DLCI 0.
-- Q933a is an LMS type defined by ITU Q.933 (also known as appendix A). Its status information is sent through DLCI 0.
· Network-to-Network Interface (NNI)-NNI is a standard used for communication between two vswitches.
Secondary failover is also used in the ATM. In ATM, NNI is called a network node interface.
When configuring a frame relay switch, you must complete the following operations:
Step 2 enable the Frame Relay switching function.
Step 2: Set the LMS interface type and frame relay interface type.
Step 2 set PVC with the fra1ne-relay route command.
In this example, you need to use two terminal devices or routers and configure a frame relay switch. Before you start
It is helpful to make a PVC chart. DCE, PVC, and interfaces must be included in the chart. This example is shown in a chart that emphasizes the network from the perspective of hardware and service providers. The intermediate Frame Relay switch has two V.35DCE cables used to connect the other two routers R1 and R2. Both routers are connected to the V35DTE public header cable at their serial ports. Set PVC to map DLCI 101 on serial port 0 to DLCI 102 on Serial Port 5.

 
 
 
 
After this chart is made, the first step for configuring the frame relay switch is to guide the frame relay switch. You can use the global configuration command frame-reIay switching to complete the switch. Then, set the serial port for frame Relay switching, and use the encapsulation frame-reIay command to encapsulate the data format into frame relay. In addition, you also need to use the frame-felaylm type [ansi | Cisco | q993a] command at the interface prompt to set the type of the LMS. Then, use the frame-relay intf-type command. Because the interface is DCE, you must use the clock rate bit/s command to set the baud rate. The bit/s value can be from 1200 to 8000000. Finally, the command frame-relay route [16-1007] inbound_DLCI interface outbound_serial_interface [16-1007] outbount_DLCI can generate a PVC on the interface and map it to another interface. The following example demonstrates the usage of these commands and the basic configuration of the frame relay switch.
Frame_switch #
Frame_switch # conf t
Enten configuration commandso, ne per 1ine. End with CNTL/2.
Frame_switch {config) # frame-relay switching
Frame_switch (config) # interface serial O/0
Frame_sv/itch (conifg-if) # encapsulation frame-relay
Fname_switch (config-if) # frame-relay lc-type cisco
Frame_switch (config-if) # frame-relay intf-type dce
Frame_switch (config-if) # clock rate 56000
Frame_switch (config-if) # frame-relay route 101 interface s0/1 102
Frame_switch (config-if) # exit
Fname_switch (config-if )#
Fname_switch (config) # interface serial 0/1
Fname_switch (config-if) # encapsulation frame-relay
Fname_switch (config-if) # frame-relay lc-type cisco
Frame_switch (config-if) # frame-relay intf-type dce
Frame_switch (config-if) # clock rate 56000
Frame_switch (config-1f) # frame-relay route 102 interface sO/0 101
Frame_switch (config-if) # exit
Frame_swi.tch (config-if )#
 
Author: "Bao Jianfeng from sharpening"