ccie lab dumps Introduction to Frame Relay Technology
Concept introduction
DTE: The frame relay network provides the ability to communicate data between user equipment (such as routers and hosts). ccie lab dumps.The user equipment is called Data Terminal Equipment (DTE);
CE: A device that provides access to a user equipment. It belongs to a network device and is called a Data Circuit-terminating Equipment (DCE).
UNI: The interface between DTE and DCE is called User Network Interface (UNI);
NNI: The interface between the network and the network is called the Network-to-Network Interface (NNI).
Virtual circuit introduction
According to different virtual circuit establishment methods, virtual circuits are classified into two types: permanent virtual circuits (PVCs) and switched virtual circuits (SVCs). The virtual circuit generated by manual setting is called a permanent virtual circuit. ccie lab dumps.The virtual circuit generated by protocol negotiation is called a switched virtual circuit. This virtual circuit is automatically created and deleted by the Frame Relay protocol. The most widely used method in frame relay is the permanent virtual circuit mode.
In the permanent virtual circuit mode, it is necessary to detect whether a virtual circuit is available. The Local Management Interface (LMI) protocol is used to detect whether a virtual circuit is available. The LMI protocol is used to maintain the PVC table of the frame relay protocol, including: notifying the increase of PVCs, detecting the deletion of PVCs, monitoring the change of PVC status, and verifying the integrity of links. ccie lab dumps.The system supports three local management interface protocols: ITU-T Q.933 Appendix A, ANSI T1.617 Appendix D, and non-standard compatible protocols.
The basic working mode of the LMI protocol is that the DTE device sends a status request packet (Status Enquiry packet) to query the status of the virtual circuit at a certain interval. After receiving the status request packet, the DCE device uses the status message immediately. (Status packet) Notifies the DTE of the status of all virtual circuits on the current interface.
For the DTE side device, the state of the permanent virtual circuit is completely determined by the DCE side device; for the DCE side device, the state of the permanent virtual circuit is determined by the network. In the case where two network devices are directly connected, the virtual circuit status of the DCE side device is set by the device administrator.
Frame Relay Address Mapping.ccie lab dumps
The frame relay address mapping is to associate the protocol address of the peer device with the frame relay address (local DLCI) of the peer device, so that the higher layer protocol can be addressed to the peer device through the protocol address of the peer device.
The frame relay is mainly used to carry the IP protocol. When sending an IP packet, the next hop address of the packet can only be known according to the routing table. Before the transmission, the corresponding DLCI must be determined by the address. ccie lab dumps .ccie lab dumps.This process can be performed by looking up the frame relay address mapping table, because the address mapping table stores the mapping relationship between the next hop IP address and the DLCI corresponding to the next hop.
The address mapping table can be manually configured or dynamically maintained by Inverse ARP (Reverse Address Resolution Protocol).
Interworking between Frame Relay Network and ATM Network.ccie lab dumps
Currently, there are three ways for interworking between a Frame Relay PVC network and an ATM network:
The first way is to interconnect two frame relay networks through an ATM network. The ATM network receives information from a frame relay network, adapts it to several ATM cells for transmission within the ATM network, and transmits ATM cell recombined frame relay information to another frame relay at the other end of the network. network. In this way, the ATM network can provide a relay transmission channel for the intranet;
The second way is the interworking between the user equipment on the frame relay network and the terminal using the frame relay protocol in the ATM network. ccie lab dumps.Interworking between the two devices through the function completion protocol and the mapping of the core frame format provided by the ATM 5th Adaptation Layer (AAL5) of the ATM;
The third way is the interworking between the user equipment on the frame relay network and the terminal that does not use the frame relay protocol on the ATM network. During interworking, the protocol and the core frame format mapping are implemented through the functions provided by the SSCS of the ATM on the AAL5 of the ATM to implement interworking between the two devices.
Publisher:IE LAB
publish Website: http://ielab.network
WhatsApp: +8617782638871
Skype:live:ielab.anna
ccie lab dumps Introduction to Frame Relay Technology
Concept introduction
DTE: The frame relay network provides the ability to communicate data between user equipment (such as routers and hosts). ccie lab dumps.The user equipment is called Data Terminal Equipment (DTE);
CE: A device that provides access to a user equipment. It belongs to a network device and is called a Data Circuit-terminating Equipment (DCE).
UNI: The interface between DTE and DCE is called User Network Interface (UNI);
NNI: The interface between the network and the network is called the Network-to-Network Interface (NNI).
Virtual circuit introduction
According to different virtual circuit establishment methods, virtual circuits are classified into two types: permanent virtual circuits (PVCs) and switched virtual circuits (SVCs). The virtual circuit generated by manual setting is called a permanent virtual circuit. ccie lab dumps.The virtual circuit generated by protocol negotiation is called a switched virtual circuit. This virtual circuit is automatically created and deleted by the Frame Relay protocol. The most widely used method in frame relay is the permanent virtual circuit mode.
In the permanent virtual circuit mode, it is necessary to detect whether a virtual circuit is available. The Local Management Interface (LMI) protocol is used to detect whether a virtual circuit is available. The LMI protocol is used to maintain the PVC table of the frame relay protocol, including: notifying the increase of PVCs, detecting the deletion of PVCs, monitoring the change of PVC status, and verifying the integrity of links. ccie lab dumps.The system supports three local management interface protocols: ITU-T Q.933 Appendix A, ANSI T1.617 Appendix D, and non-standard compatible protocols.
The basic working mode of the LMI protocol is that the DTE device sends a status request packet (Status Enquiry packet) to query the status of the virtual circuit at a certain interval. After receiving the status request packet, the DCE device uses the status message immediately. (Status packet) Notifies the DTE of the status of all virtual circuits on the current interface.
For the DTE side device, the state of the permanent virtual circuit is completely determined by the DCE side device; for the DCE side device, the state of the permanent virtual circuit is determined by the network. In the case where two network devices are directly connected, the virtual circuit status of the DCE side device is set by the device administrator.
Frame Relay Address Mapping.ccie lab dumps
The frame relay address mapping is to associate the protocol address of the peer device with the frame relay address (local DLCI) of the peer device, so that the higher layer protocol can be addressed to the peer device through the protocol address of the peer device.
The frame relay is mainly used to carry the IP protocol. When sending an IP packet, the next hop address of the packet can only be known according to the routing table. Before the transmission, the corresponding DLCI must be determined by the address. ccie lab dumps .ccie lab dumps.This process can be performed by looking up the frame relay address mapping table, because the address mapping table stores the mapping relationship between the next hop IP address and the DLCI corresponding to the next hop.
The address mapping table can be manually configured or dynamically maintained by Inverse ARP (Reverse Address Resolution Protocol).
Interworking between Frame Relay Network and ATM Network.ccie lab dumps
Currently, there are three ways for interworking between a Frame Relay PVC network and an ATM network:
The first way is to interconnect two frame relay networks through an ATM network. The ATM network receives information from a frame relay network, adapts it to several ATM cells for transmission within the ATM network, and transmits ATM cell recombined frame relay information to another frame relay at the other end of the network. network. In this way, the ATM network can provide a relay transmission channel for the intranet;
The second way is the interworking between the user equipment on the frame relay network and the terminal using the frame relay protocol in the ATM network. ccie lab dumps.Interworking between the two devices through the function completion protocol and the mapping of the core frame format provided by the ATM 5th Adaptation Layer (AAL5) of the ATM;
The third way is the interworking between the user equipment on the frame relay network and the terminal that does not use the frame relay protocol on the ATM network. During interworking, the protocol and the core frame format mapping are implemented through the functions provided by the SSCS of the ATM on the AAL5 of the ATM to implement interworking between the two devices.
Publisher:IE LAB
publish Website: http://ielab.network
WhatsApp: +8617782638871
Skype:live:ielab.anna
ccie lab dumps Introduction to Frame Relay Technology
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