Time out - transport layer, Computer Networking

Assignment Help:

Time  out

Timers  are used to protect  against  lost packet. Each  packet  must have its own logical  timers since  only  a single  packet  will be retransmitted  after timeout. A single  hardware timer can be used to mimic  the function of  multiple logical  timers.

The SR receiver  will  acknowledge  a correctly received packet whether or not it is  in order. Out of order packets  are buffered  until any missing packets ( that  is packets with lower  sequence numbers) are received. The  various actions  taken by the SR receiver.

Packet  with  sequence  number in ( rev base re base + N- 1) is correctly received. In  this case  the received packet falls within the  receiver window  and a selective ACK  packet  is returned  to the  sender.

If  the packet was not  previously  received it  is buffered. If this  packet  has a sequence number  equal to the base of the  window  then this  packet  and any  previously  buffered  and consecutively numbered packets are delivered to the receiver. The  receiver window is them moved  forward  by the number of packets  delivered to the receiver as in figure when a packet  with a  sequence number of 2 is  received  then packets 3, 4 and 5 can  be delivered to the receiver.

Packet with  sequence  number in  ( rev base n rev base-1)  is received. In  this case an ACK  must be  generated this is the packet  which  the receiver has previously  acknowledge.

Otherwise ignores the  packets.

To understand  the functions of SR protocols  lets  take an example  of a window  size of  four packets. The sender  can sends  packets 0 to 3. If  first  packet pkt 0 is  lost  and pkt 1 , 2   and 3 are received by the  receiver instead of discarding these  packets  the receiver  buffers  the packets  and send  the ACK  for the  packets  respectively. After the  time out  of pkt 0 the sender  can retransmit this  lost  packet  pkt 0 if  the receiver receives the lost  packet  pkt 0  then the  receiver deliver all the  packets  which  was kept  buffered  by the  receiver previously.


Related Discussions:- Time out - transport layer

Explain the term - global corporate-wide network, Explain the term - global...

Explain the term - global corporate-wide network It would be highly interesting to note that more than 70 per cent of all security related problems start from within the organi

Configure spanning tree- ccna, Configure Spanning Tree Step 1: Ex...

Configure Spanning Tree Step 1: Examine the default configuration of 802.1D STP. On each switch, display the spanning tree table with the show spanning-tree command. R

Determine the working of communications intranet, Determine the working of ...

Determine the working of Communications Intranet Intranets of this type tend to feature in geographically dispersed organisations. The motivation for its implementation is g

Encoding data options in parallel virtual machine , Encoding data options ...

Encoding data options PVM uses SUN's XDR library to generate a machine independent data format if you request it. Settings for the encoding option are: PvmDataDefault: Use X

What is stop-and-wait protocol, What is Stop-and-Wait Protocol? In Stop...

What is Stop-and-Wait Protocol? In Stop and wait protocol, sender sends single frame, waits unless it receives confirmation from the receiver (okay to go ahead), and then sends

What is data traffic, Q. What is Data traffic? Data traffic ...

Q. What is Data traffic? Data traffic Peak data rate : max data rate of the traffic Average data rate = (amount of data)/time Maximum Burst size: max. l

What is crc and checksum, What is CRC and Checksum CRC (Cyclic redudan...

What is CRC and Checksum CRC (Cyclic redudancy check) CRC, is the most powerful of the redundancy checking methods, is based on binary division. Checksum Checksum

Layer responsible for putting 1s and 0s into a logical group, Name the laye...

Name the layer responsible for putting 1s and 0s into a logical group? Ans) Frames are broken down into 1s and 0s and placed onto the physical medium by the Data Lin layer.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd