# Recent questions tagged tcp

1
Consider the three-way handshake mechanism followed during $\text{TCP}$ connection establishment between hosts $P$ and $Q$. Let $X$ and $Y$ be two random $32$-bit starting sequence numbers chosen by $P$ and $Q$ respectively. Suppose $P$ sends a $\text{TCP}$ connection request message to $Q$ with a ... $\text{SEQ}$ number $=Y$, $\text{ACK}$ bit $=1$, $\text{ACK}$ number $=X$, $\text{FIN}$ bit $=0$
2
A $\text{TCP}$ server application is programmed to listen on port number $P$ on host $S$. A $\text{TCP}$ client is connected to the $\text{TCP}$ server over the network. Consider that while the $\text{TCP}$ connection was active, the server machine $S$ crashed ... it will receive a $\text{RST}$ segment If the client sends a packet after the server reboot, it will receive a $\text{FIN}$ segment
3
Consider two hosts $P$ and $Q$ connected through a router $R$. The maximum transfer unit $\text{(MTU)}$ value of the link between $P$ and $R$ is $1500$ bytes, and between $R$ and $Q$ is $820$ bytes. A $TCP$ segment of size $1400$ bytes was ... lost, $P$ is required to resend the whole $\text{TCP}$ segment. $\text{TCP}$ destination port can be determined by analysing only the second fragment.
1 vote
4
In context of TCP/IP computer network models, which of the following is FALSE? Besides span of geographical area, the other major difference between LAN and WAN is that the later uses switching element. A repeater is used just to forward bits from one network to another one. IP layer is connected oriented layer in TCP/IP. A gateway is used to connect incompatible networks.
1 vote
5
A packet whose destination is outside the local $TCP/IP$ network segment is sent to ________. File server $DNS$ server $DHCP$ server Default gateway
6
Checksum field in TCP header is ones complement of sum of header and data in bytes ones complement of sum of header, data and pseudo header in $16$ bit words dropped from $\text{IPv6}$ header format better than $\text{md5}$ or $\text{sh1}$ methods
7
The persist timer is used in TCP to To detect crashes from the other end of the connection To enable retransmission To avoid deadlock condition To timeout FIN_Wait$1$ condition
1 vote
8
True or false? Consider congestion control in TCP. When the timer expires at the sender, the value of ssthresh is set to one half of its previous value.
1 vote
9
Suppose two TCP connections are present over some bottleneck link of rate R bps. Both connections have a huge file to send (in the same direction over the bottleneck link). The transmissions of the files start at the same time. What transmission rate would TCP like to give to each of the connections?
1 vote
10
Suppose Host A sends two TCP segments back to back to Host B over a TCP connection. The first segment has sequence number 90; the second has sequence number 110. How much data is in the first segment? Suppose that the first segment is lost but the second segment arrives at B. In the acknowledgment that Host B sends to Host A, what will be the acknowledgment number?
1 vote
11
True or false? Host A is sending Host B a large file over a TCP connection. Assume Host B has no data to send Host A. Host B will not send acknowledgments to Host A because Host B cannot piggyback the acknowledgments on data. The size of the TCP rwnd never ... sequence number 38 and 4 bytes of data over a TCP connection to Host B. In this same segment the acknowledgment number is necessarily 42.
1 vote
12
In our rdt protocols, why did we need to introduce timers?
1 vote
13
Why is it that voice and video traffic is often sent over TCP rather than UDP in today’s Internet? (Hint: The answer we are looking for has nothing to do with TCP’s congestion-control mechanism.)
14
Describe why an application developer might choose to run an application over UDP rather than TCP.
1 vote
15
Consider a TCP connection between Host A and Host B. Suppose that the TCP segments traveling from Host A to Host B have source port number x and destination port number y. What are the source and destination port numbers for the segments traveling from Host B to Host A?
16
List the four broad classes of services that a transport protocol can provide. For each of the service classes, indicate if either UDP or TCP (or both) provides such a service.
17
To address the limitations of IP version 4, a major effort had to be undertaken via IETF that resulted in the design of IP version 6 and there are still is significant reluctance in the adoption of this new version. However, no such major effort is needed to address the limitations of TCP. Explain why this is the case.
1 vote
18
What is the fastest line speed at which a host can blast out 1500-byte TCP payloads with a 120-sec maximum packet lifetime without having the sequence numbers wrap around? Take TCP, IP, and Ethernet overhead into consideration. Assume that Ethernet frames may be sent continuously.
19
A TCP machine is sending full windows of 65,535 bytes over a 1-Gbps channel that has a 10-msec one-way delay. What is the maximum throughput achievable? What is the line efficiency?
20
If the TCP round-trip time, RTT, is currently 30 msec and the following acknowledgements come in after 26, 32, and 24 msec, respectively, what is the new RTT estimate using the Jacobson algorithm? Use α = 0.9.
1 vote
21
Consider the effect of using slow start on a line with a 10-msec round-trip time and no congestion. The receive window is 24 KB and the maximum segment size is 2 KB. How long does it take before the first full window can be sent?
22
Describe two ways to get into the SYN RCVD state of Figure.
1 vote
23
The maximum payload of a TCP segment is 65,495 bytes. Why was such a strange number chosen?
1 vote
24
In Fig. 6-36 we saw that in addition to the 32-bit acknowledgement field, there is an ACK bit in the fourth word. Does this really add anything? Why or why not?
1 vote
25
A process on host 1 has been assigned port p, and a process on host 2 has been assigned port q. Is it possible for there to be two or more TCP connections between these two ports at the same time?
1 vote