Term
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Definition
| Permanent virtual circuit |
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Term
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Definition
| In frame relay the end of each connection has a number to identify it called a Data Link Connection Identifier. |
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Term
| How does frame relay deal with detected errors? |
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Definition
| Frame relay does not provide error correction. It drops packets without notification if an error is detected. It is up to the endpoints to notice the missing data with a protocol such as TCP |
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Term
| A DLCI identifies which part of the link? |
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Definition
| The end point of the connection. |
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Term
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Definition
| The process of obtaining an IP from the layer two address. IE Using the DLCI to obtain the IP address. |
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Term
| What is the LMI and what does it do? |
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Definition
| Local Management Interface -- It is a keep alive mechanism that provides status information about frame relay connections between the DTE and DCE about every 10 seconds. |
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Term
| What happens if you configure a specific LMI on a router? |
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Definition
| By Default a router is able to auto-sense the LMI set on the other side of the connection and match. If it is manually configured and does not match the connection will not work. |
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Term
| Name three NBMA networks. |
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Definition
| NBMA - Nonbroadcast multiacces -- Frame Relay, ATM and X.25 |
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Term
| What must be done for a frame-relay network to advertise broadcast routing protocol traffic over its connection? |
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Definition
frame-relay (appletalk, ip, ipx, ... ) (network address of destination router) (dlci#) BROADCAST
The key word broadcast allows the broadcast traffic to be transferred as a unicast over the connection. |
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Term
| What are the three parts of paying for a frame relay circuit? |
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Definition
Access Speed
PVC -- Number of established connections
CIR - Committed information rate. Guaranteed traffic amount allowed. |
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Term
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Definition
| Committed burst information rate and Excess Burst Size. Both refer to the amount one is over their CIR (committed information rate) all packets in this range are DE (discard eligible) |
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Term
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Definition
| FECN - Forward Explicit Congestion Notification -- Tell routers downstream of congestion that congestion is occurring upstream. |
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Term
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Definition
| Backward Explicit Congestion Notification -- DTE's receiving BECN notification are expected to try to reduce the flow of frames until the congestion clears |
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Term
| What happens to a packet destined to subinterface s0/0/0.10 (10.10.10.5/30) when the physical interface s0/0/0 has the address 10.10.10.2/30. |
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Definition
| If the physical interface has an ip address packets do not go to the subinterfaces. |
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Term
| Name two reasons Frame relay is more cost-effective than leased lines. |
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Definition
It uses less equipment.
It shares bandwidth across a large customer base. |
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Term
| What reliability advantage does Frame Relay offer over leased lines? |
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Definition
| the pathways for virtual circuits inside the carrier are meshed which allows for redundancy. |
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Term
| Which two items allow the router to map data link layer addresses to network layer addresses in a Frame Relay network? |
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Definition
Inverse ARP
LMI Status message |
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