# Recent questions tagged computer-network

Which of the following timers is known to keep the window size flowing even if the connection is terminated on the other end? Persistent Timer Keep Alive Timer Retransmission timer Time out timer
Consider a system with 3 network connected via two router, network A has MTU of 800 bytes, network B has MTU of 400 bytes, network C has MTU of 800 bytes. They have considered Data as 680 itself, but shouln’t we do 680-20 =660, or as they have mentioned segment instead of packet that is why we are not subtracting the header?
Ans should be 2 right?
Both A and C should be ans right?
Question: 27 Suppose an organisation has CIDR based IP address 215.58.204.10./20, Organisation decided to divide the network into three subnet name as X, Y, Z respectively. Which of the following is a valid IP address of the subnet Y? 1. 215.58.192.12/22 2. 215.58.201.100/22 ... 254/21 4. None of these According to me both a and b can be the ans, but they have provided only B as ans. Who is right?
Note→ MULTIPLE OPTIONS CORRECT
I am facing serious troubles while calculating number of fragments. I read a formula #fragments = ceil (payload/ mtu-header) but this isn't giving correct answer in all the cases. Before I show my approach, I would like to ask what does PDU imply? Does it mean header is ... formula 1 #frags= ceil(17076/180)=95 Using formula 2, #frags= ceil(17076/176)=98 No match either. Where am I going wrong?
Consider the population of various continents as follows: Africa - 900 Million; Asia - 3700 Million; North America-400 Million; South America-500 Million; Europe- 700 Million; Consider the above data. Suppose each person requires 100 IP addresses. Then design an appropriate CIDR scheme that ... 2^1$^0$) OPTIONS a. b. C It is not possible to fulfil the above requirement D Both A and B are valid
A 40 Mbps broadcast network that controls medium access using polling has 20 hosts and time required for polling the next host is 80 μsec. whenever a node is polled, it is allowed to transmit 4000 bytes. Find the efficiency of the broadcast channel (A) 100/9 (B) ... or Polling, if there are n hosts, will the total bandwidth get divided among the hosts or will all hosts transmit at full capacity?
Assuming that, for given network layer implementation, connection establishment overheads are 100 bytes and disconnection are 28 bytes, what would be the minimum size of a packet the transport layer needs to keep if it wishes to implement a datagram service above network ... to keep its overhead to a maximum of 12.5%. Ignore transport layer overheads. 512 bytes 768 bytes 1152 bytes 1024 bytes
Consider host A wants to transmits a 25000 bytes long file to host B using TCP. If MSS is 1000 bytes and slow start threshold is 16 MSS. How many RTT it will take to transmits the complete file?
Consider a TCP based protocol over 40 Gbps; A single TCP connection is allowed to use all the available bandwidth. How long wraparound occurs in sec?
Can anyone explain how to approach the question and tell the solution ? Given ans is 176 ms .
Consider two host connected to each other over 1Mbps link where distance between them is 10,000 km and propagation speed is 2*10^8 m/s. If frame size 1000 Byte and window size is 5. What is maximum achievable throughput if ack are always piggybacked?
Consider that at time t, a TCP connections has a congestion window of 4000 bytes. The maximum segment size used by the connection is 1000 bytes. What is the congestion window(in bytes) after it send out 4 packets and receive acks for all of them? Suppose thre is one ack per packet. If the connection is in slow start? If the connection is in congestion avoidance?
If a TCP server was to simultaneously support N clients, how many sockets would the TCP server need? 1 2 N N+1 Please answer the above question for UDP also.
A 3000-km-long T1 trunk is used to transmit a 64-byte frame. Assume the propagation speed is 6microsec/km. (Note that the data rate for T1 carries is 1.544 Mbps). If go-back-N protocol is used,in order to achieve an efficiency of 100%. What is the maximum number of bits of the sequence number?