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. |