Question

Tcp connection is transferringa file of 5000 bytes the 1st bytes is numbered 10001 what are the sequence number for each segment if data are sent in five segment each carry 1000 byte

Answer 1

1. Chapter 12 Transmission Control Protocol Objectives Upon completion you will be able to: • Be able to name and understand the services offered by TCP • Understand TCP’s flow and error control and congestion control • Be familiar with the fields in a TCP segment • Understand the phases in a connection-oriented connection • Understand the TCP transition state diagram • Be able to name and understand the timers used in TCP • Be familiar with the TCP options TCP/IP Protocol Suite 12. Figure 12.1 TCP/IP protocol suite TCP/IP Protocol Suite 23. 12.1 TCP SERVICES We explain the services offered by TCP to the processes at the application layer. The topics discussed in this section include: Process-to-Process Communication Stream Delivery Service Full-Duplex Communication Connection-Oriented Service Reliable Service TCP/IP Protocol Suite 34. Table 12.1 Well-known ports used by TCP TCP/IP Protocol Suite 45. Example 1 As we said in Chapter 11, in UNIX, the well-known ports are stored in a file called /etc/services. Each line in this file gives the name of the server and the well-known port number. We can use the grep utility to extract the line corresponding to the desired application. The following shows the ports for FTP. $ grep ftp /etc/services ftp-data 20/tcp ftp-control 21/tcp TCP/IP Protocol Suite 56. Figure 12.2 Stream delivery TCP/IP Protocol Suite 67. Figure 12.3 Sending and receiving buffers TCP/IP Protocol Suite 78. Figure 12.4 TCP segments TCP/IP Protocol Suite 89. 12.2 TCP FEATURES To provide the services mentioned in the previous section, TCP has several features that are briefly summarized in this section. The topics discussed in this section include: Numbering System Flow Control Error Control Congestion Control TCP/IP Protocol Suite 910. Note: The bytes of data being transferred in each connection are numbered by TCP. The numbering starts with a randomly generated number. TCP/IP Protocol Suite 1011. Example 2 Suppose a TCP connection is transferring a file of 5000 bytes. The first byte is numbered 10001. What are the sequence numbers for each segment if data is sent in five segments, each carrying 1000 bytes? Solution The following shows the sequence number for each segment: Segment 1 ➡ Sequence Number: 10,001 (range: 10,001 to 11,000) Segment 2 ➡ Sequence Number: 11,001 (range: 11,001 to 12,000) Segment 3 ➡ Sequence Number: 12,001 (range: 12,001 to 13,000) Segment 4 ➡ Sequence Number: 13,001 (range: 13,001 to 14,000) Segment 5 ➡ Sequence Number: 14,001 (range: 14,001 to 15,000) TCP/IP Protocol Suite 1112. Note: The value in the sequence number field of a segment defines the number of the first data byte contained in that segment. TCP/IP Protocol Suite 1213. Note: The value of the acknowledgment field in a segment defines the number of the next byte a party expects to receive. The acknowledgment number is cumulative. TCP/IP Protocol Suite 1314. 12.3 SEGMENT A packet in TCP is called a segment The topics discussed in this section include: Format Encapsulation TCP/IP Protocol Suite 1415. Figure 12.5 TCP segment format TCP/IP Protocol Suite 1516. Figure 12.6 Control field TCP/IP Protocol Suite 1617. Table 12.2 Description of flags in the control field I TCP/IP Protocol Suite 1718. Figure 12.7 Pseudoheader added to the TCP datagram TCP/IP Protocol Suite 1819. Note: The inclusion of the checksum in TCP is mandatory. TCP/IP Protocol Suite 1920. Figure 12.8 Encapsulation and decapsulation TCP/IP Protocol Suite 2021  

Answer 2

Explanation:

Answer» B. 10001Explanation: the sequence number given to first byte of a segment, with respect to its order among the previous segments, is the sequence number of that segment.