Link layer process, Computer Networking

Each link layer process will have two connections: one "up" to the appropriate IP layer process, and one "sideways" to the link layer process on the simulated machine at the other end of its link.

Each link layer uses variable-length frames with these ?elds in this order:

  • Source (1 byte)
  • Destination (1 byte)
  • Protocol (1 byte)
  • Length, in bytes, of data ?eld (1 byte)
  • Data (0-MTU bytes)

There is no CRC. You must ensure that every frame sent among link processes has correct values for all ?elds. The MTUs are as follows:

  • A-R1 = 64 bytes
  • B-R1 = 64
  • C-R2 = 80
  • D-R2 = 80
  • R1-R2 = 56

Notice that all MTUs must be 255 or less because each link layer's frame length ?eld is a single byte.

The link addresses of A, B, C, D are 2, 3, 5, and 7, respectively. The link address of R1 to be used by A and B is 11. The link address of R2 to be used by C and D is 13. R1 and R2 are attached to a third link. The link address of R1 to be used by R2 is 17. The link address of R2 to be used by R1 is 19. The protocol number for IP is 42.

A link layer process is simple: it calls select(2), awaiting input on either connection. When input is available from the IP process, it is read, encapsulated in a single frame if possible, and then the frame is written into the connection to the other link process. (If the IP process attempts to send an IP datagram that is too big to ?t in a single frame, an error should be returned. On UNIX, this error is EMSGSIZE.)

When input is available from the other link process it is veri?ed to be a frame carrying IP data, and, if so, the frame's header is stripped and its data ?eld written into the IP connection. If the frame is erroneous, it is silently dropped.

Posted Date: 3/15/2013 12:58:37 AM | Location : United States







Related Discussions:- Link layer process, Assignment Help, Ask Question on Link layer process, Get Answer, Expert's Help, Link layer process Discussions

Write discussion on Link layer process
Your posts are moderated
Related Questions
Q. Define Metropolitan Area Network? Metropolitan Area Network (MAN) Cable Network Architecture: Overview Protocols and Standards - Set of regulations that go

802.11a OFDM a) Orthogonal frequency-division multiplexing utilizing a 5-GHz band b) Same as FDM except all sub bands are used by only one source at a given time c)  Secu

Your Windows client failed to broadcast to all servers that it has accepted an IP address offer. What step is this in the four-step DORA process? a. Discovery b. Offering c. Reques

What is ipconfig? Ipconfig is a utility program that is commonly used to recognize the addresses information of a computer on a network. It can show the physical address as wel

Q. What is network layer of osi model? - Describe end-to-end delivery of packets. - Defines logical addressing thus that any endpoint can be identified. - Defines how ro

In Windows 2000, a domain describes both an administrative boundary and a security boundary for a collection of objects that are relevant to a particular group of users on a networ

The entire idea of ISDN is to digitize the telephone network to allow the transmission of video, audio and text over existing telephone lines. The reason of the ISDN is to provide

Ajax is a relatively new set of techniques that, in a sense, implement some of the functionalities originally provided by RPC. Ajax is primarily used to build web applications with

Random forests : An ensemble of the classification or the regression trees (see the classification and regression tree methods) that have been fitted to the same n observations, bu

Describe what is meant by Asymmetric Multiprocessing (AMP)? Ans) It imposses hierarchy and a division of labour between processors. Only one designated processor, the master, co