What will be amount of data , acknowledgement number and sequence number for tcp connection?

Consider a TCP connection in a state where there are no outstanding ACKs. The sender sends two segments back to back. The sequence numbers of the first and second segments are 230 and 290 respectively. The first segment was lost, but the second segment was received correctly by the receiver. Let X be the amount of data carried in the first segment (in bytes), and Y be the ACK number sent by the receiver. 
The values of X and Y (in that order) are

  1. 60 and 290
  2. 230 and 291
  3. 60 and 231
  4. 60 and 230
2Comments
set2018 @setgate
11 Sep 2017 05:18 pm

first sequence number =230

second segment number 290

for 1st segment

230+x-1=289

x=60

As we know acknowledgement number is next expected byte 

but in given question 1 segment is lost ,As this is tcp connection .for connection establishment first sequence number from reciver side will be 230 only .

if question is about 2 nd segment then it will be 291 

m approaching right ?

shivani @shivani1234
25 Sep 2017 04:30 pm

If 2nd segment is lost , then ack no. will be 290 as segment 1 range is from 230 to 289.