Chapter 14


1:

Does Frame Relay perform flow control over the frames ?

A1:

No, Frame Relay drops frames on congestion.

2:

Name the FRF implementation agreement that governs data compression over Frame Relay.

A2:

FRF .9.

3:

Define the main components of the full LAPF protocol.

A3:

The full LAPF protocol includes core LAPF and control LAPF .

4:

Name the components of the Frame Relay format.

A4:

Beginning and ending Flag field, Address field, Information (Data) field, and FCS field.

5:

What is the maximum frame size that FCS can provide error detection for?

A5:

The FCS code provides error detection for frames up to 4096 bytes in length.

6:

What is the zero-insertion procedure and why is it necessary?

A6:

Zero-insertion is looking for non-flag data pattern 011111. It inserts a zero to distinguish between flags and data.

7:

How many DLCI address field formats are available?

A7:

The default Address field format is 2 bytes or 10 bits. The extended address frame format can be 3 bytes (16 or 17 bits) or 4 bytes (23 bits).

8:

What does the DE bit stand for and who can set it?

A8:

Discard eligible (DE) indicates the importance of the packet. It can be set by the user and by the network.

9:

Name the LMI numbers for Consortium and AnnexD specifications.

A9:

Consortium uses DLCI = 1023 for LMI . AnnexD uses DLCI = 0 for LMI .

10:

What is the main difference between the core format and control protocol format of LAPF?

A10:

The main difference between the core format and the control protocol format is the control field.

11:

Name the four categories of signaling messages of the LAPF control protocol.

A11:

LMIs, T1.617 AnnexD messages, CLLM messages, and SVC messages.

12:

What is the purpose of the Dummy Call Reference in the Q.931 header?

A12:

To indicate that the message is not a call establishment, disconnect, or status message.




Troubleshooting Remote Access Networks CCIE Professional Development
Troubleshooting Remote Access Networks (CCIE Professional Development)
ISBN: 1587050765
EAN: 2147483647
Year: 2002
Pages: 235

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