ICND2 Chapter 15 Flashcards
Chapter 15: Frame Relay Concepts
Frame Relay Virtual circuit (VC)
A logical concept that represents the path that frames travel between DTEs. VCs are particularly useful when you compare Frame Relay to leased physical circuits.
Frame Relay Permanent virtual circuit (PVC)
A predefined VC. A PVC can be equated to a leased line in concept.
Frame Relay Switched virtual circuit (SVC)
A VC that is set up dynamically when needed. An SVC can be equated to a dial connection in concept.
Frame Relay Data terminal equipment (DTE)
DTEs are connected to a Frame Relay service from a telecommunications company. They typically reside at sites used by the company buying the Frame Relay service.
Frame Relay Data communications equipment (DCE)
Frame Relay switches are DCE devices. DCEs are also known as data circuit-terminating equipment. DCEs are typically in the service provider’s network.
Frame Relay Access link
The leased line between the DTE and DCE.
Frame Relay Access rate (AR)
The speed at which the access link is clocked. This choice affects the connection’s price.
Frame Relay Committed Information Rate (CIR)
The speed at which bits can be sent over a VC; according to the business contract between the customer and provider.
Frame Relay Data-link connection identifier (DLCI)
A Frame Relay address used in Frame Relay headers to identify the VC.
Frame Relay Nonbroadcast Multiaccess (NBMA)
A network in which broadcasts are not supported ; but more than two devices can be connected.
Frame Relay Local Management Interface (LMI)
The protocol used between a DCE and DTE to manage the connection. Signaling messages for SVCs; PVC status messages and keepalives are all LMI messages.
Frame Relay LMI type: Cisco
Document: Proprietary; Parameter: cisco
Frame Relay LMI type: ANSI
Document: T1.617 Annex D; Parameter: ansi
Frame Relay LMI type: ITU
Document: Q.933 Annex A; Parameter: q933a