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

Urgent pointer - transport layer, Urgent Pointer This 16 bite whic...

Urgent Pointer This 16 bite which is valid  only f the urgent  flag is set is used  when the segment  contains  urgent data. If  defines  the number  that must be  added  t

Ethernet interface on the cisco router , As a system administrator, you req...

As a system administrator, you require to set up single Ethernet interface on the Cisco router to permit for both sap and Novell-ether encapsulations. Which set of commands will ac

Subtract two from number of hosts, Why do we require to subtract two from n...

Why do we require to subtract two from number of hosts?

What are general middleware, What are General Middleware? It contains t...

What are General Middleware? It contains the communication stacks, authentication services, distributed directories, network time, RPC, Queuing services with the network OS ext

What is domains in active directory, In Windows 2000, a domain describes bo...

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

Define the backbone networks, Q. Define the Backbone Networks? Backbon...

Q. Define the Backbone Networks? Backbone Networks - Allows several LANs to be connected - Non of station is directly connected to the backbone - Stations are part

Receive window - transport layer, Receive Window This  field  defin...

Receive Window This  field  defines the size  of the  window in bytes  that the  other party  must  maintain. Note  that the  length  of this  field 16 bits  which  means

Packets in eigrp, What are different kinds of packets in EIGRP?

What are different kinds of packets in EIGRP?

Show the error correction by hamming code, Q. Show the Error Correction by ...

Q. Show the Error Correction by Hamming Code? Hamming Code is able to be applied to data units of any length and uses the relationship between data and redundancy bits For i

Introduction of dns - domain name server, Introduction of DNS While di...

Introduction of DNS While discussing about the Internet, one things comes automatically in the n=mind and hence it is directly or indirectly depended on DNS. The DNS which sta

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