Solved

TCP/IP the contradiction...?

Posted on 2002-05-20
5
391 Views
Last Modified: 2013-11-29
In TCP/IP four layer model, The second Layer is Network Layer Which consists of protocols Like IP,ICMP..Similarly the above Layer Transport Layer consists of protocols like TCP & UDP. My Q is
 
  TCP is - Connection Oriented Protocol
  But the Lower Layer
  IP is - Connectionless Protocol.

 How these two layers communicates & How actually communication is handled in Tcp/Ip model ?
0
Comment
Question by:devisakthi
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
5 Comments
 
LVL 1

Assisted Solution

by:mmedwid
mmedwid earned 25 total points
ID: 7022153
0
 
LVL 9

Expert Comment

by:TooKoolKris
ID: 7022209
Actually the second layer from the bottom is the Data Link layer not the Network Layer, that is the 3rd from the bottom. mmedwid has a good article there for understanding the model. If you are interested in really learning TCP/IP and OSI Modeling then stay with the Cisco based learning materials, they are far above the rest.

TooKoolKris,
MCSE+I, CCNA, A+
0
 
LVL 5

Accepted Solution

by:
dcgames earned 25 total points
ID: 7022212
Saying that TCP/IP is connection-oriented means that the TCP protocol provides what appears to be a well organized, error free "pipe". You establish the pipe between two ends and data you put in on one side goes out the other in the same order and w/out errors.

In reality, TCP just hands it down to the lower layer (connection-less). The lower layer transmits the info w/out any warranty on the order of arrival. The TCP layer at the other end picks up the pieces and re-assembles them. If one is missing, it asks for retransmission. If they are out of order, it puts them back in order.

There are many layers, each using the lower layer to implement itself.

It all boils down in the end to pretty much the same layers with minor variations regardless of what "network" you are talking about.

Application layer on top of
Transport Layer on top of
Network Layer on top of
Logical Layer on top of
Physical Layer

I use "Application" very roughly here. The main interest is in the lower 4 (transport, network, logical, physical).

TCP or UDP are transport layers riding on the IP layer. Notice that TCP is connection oriented but UDP is not. Since IP is not connection oriented, then TCP must do a lot more work than UDP. This is why TCP is more "expensive" in terms of network load than UDP.

IP is the "network" layer over which TCP, UDP, ICMP, ARP, and other protocols ride. So are AppleTalk and Netware.

Ethernet is a "logical" layer over which IP rides (but not the only layer on which IP could ride).

IE 802.x (or something like that) is the "physical" layer over which the Ethernet protocol rides (but not the only physical layer on which Ethernet coul ride).

Note that most protocols fit into this layered model, even if the fit isn't perfect.

ICMP for example is used by PING. You could call PING the "application" layer and ICMP the "transport" layer, riding on IP.

Dave
0
 
LVL 5

Expert Comment

by:dcgames
ID: 7022231
I did this from memory, so there are bound to be some minor errors in the above. Yes, the second layer is "data link" not "logical" .. I knew it didn't sound right when I wrote it, but I was talking on the phone while I typed :-D


Dave
0
 

Expert Comment

by:CleanupPing
ID: 9155665
devisakthi:
This old question needs to be finalized -- accept an answer, split points, or get a refund.  For information on your options, please click here-> http:/help/closing.jsp#1 
EXPERTS:
Post your closing recommendations!  No comment means you don't care.
0

Featured Post

Creating Instructional Tutorials  

For Any Use & On Any Platform

Contextual Guidance at the moment of need helps your employees/users adopt software o& achieve even the most complex tasks instantly. Boost knowledge retention, software adoption & employee engagement with easy solution.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Printer Access denied on reboot 5 92
Samples DNS record setting. 5 59
Samsung Tablet no Internet but does connect to WiFi 7 52
Need to cut my Verizon home cost 3 67
Meet the world's only “Transparent Cloud™” from Superb Internet Corporation. Now, you can experience firsthand a cloud platform that consistently outperforms Amazon Web Services (AWS), IBM’s Softlayer, and Microsoft’s Azure when it comes to CPU and …
When you try to share a printer , you may receive one of the following error messages. Error message when you use the Add Printer Wizard to share a printer: Windows could not share your printer. Operation could not be completed (Error 0x000006…
Viewers will learn how to connect to a wireless network using the network security key. They will also learn how to access the IP address and DNS server for connections that must be done manually. After setting up a router, find the network security…
Internet Business Fax to Email Made Easy - With  eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, f…

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question