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Flashcards in WAN Deck (42):
1

Define PPP

An Internet standard serial data-link protocol, used on synchronous and asynchronous links, that provides data-link framing, link negotiation, Layer 3 interface features, and other functions.

2

Define MLP

A PPP feature used to load balance multiple parallel links at Layer 2 by fragmenting frames, sending one frame over each of the links in the bundle, and reassembling them at the receiving end of the link.

3

Define LCP

The portion of PPP focused on features that are unrelated to any specific Layer 3 protocol.

4

Define NCP

The portions of PPP focused on features that are related to specific Layer 3 protocols.

5

Define IPCP

The portion of PPP focused on negotiating IP features—for example, TCP or RTP header compression.

6

Define CDPCP

The portion of PPP focused on supporting the CDP protocol.

7

Define MLP LFI

The PPP function for fragmenting packets, plus interleaving delay-sensitive later-arriving packets between the fragments of the first packet.

8

Define CHAP

An Internet standard authentication protocol that uses secure hashes and a three-way handshake to perform authentication over a PPP link.

9

Define PAP

An Internet standard authentication protocol that uses clear-text passwords and a two-way handshake to perform authentication over a PPP link.

10

Define LFI

The process of breaking a frame into pieces, sending some of the fragments, and then sending all or part of a different packet, all of which is done to reduce the delay of the second packet.

11

Define Layer 2 payload compression

The process of taking the payload inside a Layer 2 frame, including the headers of Layer 3 and above, compressing the data, and then uncompressing the data on the receiving router.

12

Define TCP header compression

The process of taking the IP and TCP headers of a packet, compressing them, and then uncompressing them on the receiving router.

13

Define RTP header compression

The process of taking the IP, UDP, and RTP headers of a voice or video packet, compressing them, and then uncompressing them on the receiving router.

14

Define FRF

A vendor consortium that formerly worked to further Frame Relay common vendor standards.

15

Define VC

A logical concept that represents the path over which frames travel between DTEs. VCs are particularly useful when comparing Frame Relay to leased physical circuits.

16

Define PVC

A predefined VC. A PVC can be equated to a leased line in concept.

17

Define SVC

A VC that is set up dynamically when needed. An SVC can be equated to a dial-on-demand connection in concept.

18

Define DTE

From one perspective, DTE devices are one of two devices on either end of a communications circuit, specifically the device with less control over the communications. In Frame Relay, routers connected to a Frame Relay access link are DTE devices.

19

Define DCE

DCE devices are one of two devices on either end of a communications circuit, specifically the device with more control over the communications. Frame Relay switches are DCE devices. DCEs are also known as data circuit-terminating equipment (DTE).

20

Define LMI

The Frame Relay protocol used between a DCE and DTE to manage the connection. Signaling messages for SVCs, PVC Status messages, and keepalives are all LMI messages.

21

Define access rate

The speed at which the access link is clocked. This choice affects the price of the connection and many aspects of traffic shaping and policing, compression, quality of service, and other configuration options.

22

Define access link

In Frame Relay, a link between a router and a Frame Relay switch.

23

Define FRF.9

An FRF standard for payload compression.

24

Define FRF.5

An FRF standard for Frame Relay-to-ATM Service Interworking in which both DTEs use Frame Relay, with ATM in between.

25

Define FRF.8

An FRF standard for Frame Relay-to-ATM Service Interworking in which one DTE uses Frame Relay and one uses ATM

26

Define service interworking

The process, defined by FRF.5 and FRF.8, for combining ATM and FR technologies for an individual VC.

27

Define FRF.12

An FRF standard for LFI for data (FRF.3) VCs.

28

Define FRF.11-c

An FRF standard for LFI for VoFR (FRF.11) VCs, in which all voice frames are interleaved in front of data frames’ fragments.

29

Define VoFR

Defined in FRF.11, an FR VC that uses a slightly varied header, as compared with FRF.3 data VCs, to accommodate voice payloads directly encapsulated inside the Frame Relay LAPF header.

30

Define LAPF

An ITU standard Frame Relay header, including the DLCI, DE, FECN, and BECN bits in the LAPF header, and a frame check in the LAPF trailer.

31

Define NLPID

Network Layer Protocol ID is a field in the RFC 2427 header that is used as a Protocol Type field in order to identify the type of Layer 3 packet encapsulated inside a Frame Relay frame.

32

Define DE

A bit in the Frame Relay header that, when set to 1, means that if a device needs to discard frames, it should discard the frames with DE 1 first.

33

Define FECN

A bit in the LAPF Frame Relay header that, when set to 1, implies that the frame has experienced congestion.

34

Define BECN

A bit inside the Frame Relay header that, when set, implies that congestion occurred in the direction opposite (or backward) as compared with the direction of the frame.

35

Define Dual FIFO

A Cisco IOS interface software queue queuing strategy implemented automatically when using either form of Frame Relay fragmentation. The system then interleaves packets from the high-priority queue between fragments of the medium-priority queue.

36

Define LZS

The Lempel Ziv STAC compression algorithm is used in Frame Relay networks to define dynamic dictionary entries that list a binary string from the compressed data and an associated smaller string that represents it during transmission—thereby reducing the number of bits used to send data.

37

Define DLCI

A Frame Relay address used in Frame Relay headers to identify the VC

38

Define frame relay lfi using multilink ppp

A method of Link Fragmentation and Interleaving (LFI) over interfaces that natively use Frame Relay encapsulation. The routers first build MLP-style PPP headers, which are then encapsulated inside a Frame Relay header. The PPP headers are then used to implement MLP LFI.

39

LMI Status what are they and what do they mean?

Active
- Healthy on each end and data can be transferred
* INACTIVE
- Local connection is healthy, but remote side is not
* DELETED
- No LMI, or the DLCI was deleted from the switch.

40

What are the three LMI options?

Cisco, ANSI, Q.933 Annex A

41

What is the formula for calculating the number of Virtual Circuits (VC's) needed for a full mesh Frame Relay Network?

n(n-1)/2 where n is the number of nodes

42

Reserved DLCIs

0 - 15 and 1008 - 1023