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9 Cards in this Set
- Front
- Back
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How do Frame Relay switches know how to route Frame Relay frames?
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The Frame Relay header contains a DLCI (data link connection identifier) field, which tell the provider's switches know which VC the frame belongs to and where to route it.
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What is a CIR?
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Committed information rate. The bandwidth guaranteed by the ISP for a particular VC.
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What is LMI?
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The protocol used for communication between the DTE and the DCE. Cisco IOS supports three: Cisco, ITU, and ANSI.
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What is DTE?
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Data terminal equipment (for instance a router).
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What is DCE?
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Data communication equipment (for instance the Frame Relay switch owned by the ISP).
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Does Frame Relay forward broadcast frames?
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No, there is no broadcast address or broadcast domain.
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What is Frame Relay Service Interworking?
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The use of ATM between two Frame Relay switches.
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What is Frame Relay Address Mapping, and how does it work?
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Routers build a table mapping VC's to DLCI numbers. That way, when a packet arrives the router looks up the route in its routing table. It determines which interface the packet should be sent out, and looks at the Frame Relay configuration for that interface, which includes the DLCI's for all the VC's bound to that interface. Those DLCI's are then looked up in the address map, where each is mapped to a Layer 3 address.
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How are entries added to the Frame Relay Address Map?
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Either statically defined, or through inverse ARP. Inverse ARP causes every router to send an annoucement with its network layer address as soon as a VC comes up (those announcements contain the DLCI in the header). The two values are added to the table.
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