Computer Networking: A Top-Down Approach (7th Edition)
Computer Networking: A Top-Down Approach (7th Edition)
7th Edition
ISBN: 9780133594140
Author: James Kurose, Keith Ross
Publisher: PEARSON
Question
Book Icon
Chapter 2, Problem P17P

a)

Program Plan Intro

UIDL POP3 Command:

UIDL stands for Unique-Id Listing.

  • The fact that optional UIDL command is supported is indicated by the UIDL capability.
  • A unique number to each incoming mail message are assigned by POP3 servers.
  • When a POP3 client issues the UIDL command, the server responds with the unique message ID in mailbox.
  • The UIDL POP3 Command is used for “download and keep”, which allows mail to be left on the server after it has been downloaded to the user. Both the mail client and the POP server must support this feature.
  • The client can use the UIDL command to determine which messages on the server has already been seen by maintaining a file that lists the messages received during earlier sessions.

Given transaction:

Suppose one has configured their POP mail client to operate in the download-and-delete mode. The transaction is given as below:

C: list (client asks server to list the size of each of the stored messages)

S: 1 498 (Server lists the size of message 1)

S: 2 912 (Server lists the size of message 2)

S: .

C: retr 1 (Client requests to read message 1)

S: blah blah …  (Sends message 1)

S: ………blah

S: .

b)

Program Plan Intro

UIDL POP3 Command:

UIDL stands for Unique-Id Listing.

  • The fact that optional UIDL command is supported is indicated by the UIDL capability.
  • A unique number to each incoming mail message are assigned by POP3 servers.
  • When a POP3 client issues the UIDL command, the server responds with the unique message ID in mailbox.
  • The UIDL POP3 Command is used for “download and keep”, which allows mail to be left on the server after it has been downloaded to the user. Both the mail client and the POP server must support this feature.
  • The client can use the UIDL command to determine which messages on the server has already been seen by maintaining a file that lists the messages received during earlier sessions.

Given transaction:

Suppose one has configured their POP mail client to operate in the download-and-keep mode. The transaction is given as below:

C: list (client asks server to list the size of each of the stored messages)

S: 1 498 (Server lists the size of message 1)

S: 2 912 (Server lists the size of message 2)

S: .

C: retr 1 (Client requests to read message 1)

S: blah blah …  (Sends message 1)

S: ………blah

S: .

c)

Program Plan Intro

UIDL POP3 Command:

UIDL stands for Unique-Id Listing.

  • The fact that optional UIDL command is supported is indicated by the UIDL capability.
  • A unique number to each incoming mail message are assigned by POP3 servers.
  • When a POP3 client issues the UIDL command, the server responds with the unique message ID in mailbox.
  • The UIDL POP3 Command is used for “download and keep”, which allows mail to be left on the server after it has been downloaded to the user. Both the mail client and the POP server must support this feature.
  • The client can use the UIDL command to determine which messages on the server has already been seen by maintaining a file that lists the messages received during earlier sessions.

Given transaction:

Suppose one configured the POP mail client to operate in the download-and-keep mode. Then using the transcript in part b, suppose one retrieves messages 1 and 2, exit POP, and then five minutes later can again access POP to retrieve new e-mail. The given transaction is:

C: list (client asks server to list the size of each of the stored messages)

S: 1 498 (Server lists the size of message 1)

S: 2 912 (Server lists the size of message 2)

S: .

C: retr 1 (Client requests to read message 1)

S: blah blah …  (Sends message 1)

S: ………blah

S: .

C: retr 2

S: blah blah …

S: ………..blah

S: .

C: quit

S: +OK POP3 server signing off

Blurred answer
Students have asked these similar questions
Problem 3: Consider the two-link planar elbow manipulator shown below with link information: a₁ = 3, a₂ = 3. a2 S 3/0 Link | a | ai | di ai | di | 0i | มา 02 21 02. 12 01 0 0 01 02 0 0 02 01 To (a) Find the location of the end-effector P° if the joint angles are: 0₁ = 140°, 0₂ = 30° (b) Find the values of joint variables 01, 02 if the robotic manipulator is commanded to reach the desired location of Pº = [4.5, 3,0]. Notice there are possibly two sets of solutions. (c) Also sketch the two poses of the robot for the computed joint variables. Page 5 of 7
Problem 5: The following shows the schematic of a SCARA robot and its DH parameters. Complete the following questions based on this information. 20 01 21 02. 22 done by ai α; di Ꮎ ; 21 d3 1 a1 0 0 0₁** 2 a2 180° 0 0% 3 0 0 d3 0 The Jacobian matrix of this robot is given below: -a1S1a2S12 -a2S12 J(q) = a1c1 + a2c12 0 a2C12 0 10° (a) For a₁ = 1, a2 = 2, is q = 180° a singularity configuration of this robot? a1 3 [10°1 (b) For a₁ = 1, a2 = 2, is q = | 0° a singularity configuration of this robot? 3
(c) Consider the following sequence of rotations: 1) Rotate by 130° about the world z-axis 2) Rotate by 45° about the current x-axis 3) Rotate by -30° about the world/fixed y-axis Compute the resulting overall rotation matrix R. Notice that you need to provide the numerical solution to the matrix R. (d) Find R giving the following rotation matrices. 1 0 0 1 √√3 го о 0 0 R₁₁ = 2 R₁ = 0 1 0 1 0 0 0 2 2
Knowledge Booster
Background pattern image
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Computer Networking: A Top-Down Approach (7th Edi...
Computer Engineering
ISBN:9780133594140
Author:James Kurose, Keith Ross
Publisher:PEARSON
Text book image
Computer Organization and Design MIPS Edition, Fi...
Computer Engineering
ISBN:9780124077263
Author:David A. Patterson, John L. Hennessy
Publisher:Elsevier Science
Text book image
Network+ Guide to Networks (MindTap Course List)
Computer Engineering
ISBN:9781337569330
Author:Jill West, Tamara Dean, Jean Andrews
Publisher:Cengage Learning
Text book image
Concepts of Database Management
Computer Engineering
ISBN:9781337093422
Author:Joy L. Starks, Philip J. Pratt, Mary Z. Last
Publisher:Cengage Learning
Text book image
Prelude to Programming
Computer Engineering
ISBN:9780133750423
Author:VENIT, Stewart
Publisher:Pearson Education
Text book image
Sc Business Data Communications and Networking, T...
Computer Engineering
ISBN:9781119368830
Author:FITZGERALD
Publisher:WILEY