In physical layer data is represented in the form of

• Packets

• bits

• frames

• segments

• a

• b

• c

• d

Protocol field in IPv4 header is '1' then it indicates

• TCP packet

• ICMP packet

• UDP packet

• None of these

your roll number?

ICMP error messages are transmitted by

• Intermediate routers

• Destination host

• sender

• both a and b

SMTP is

• Default port is 30

• Textbase protocol

• Push protocol

• Both Textbase protocol and Push protocol

Which one of following fields of an IP header is not modified by typical IP router?

• Checksum

• Source address

• Time to live

• Length

HTTP has

• Persistent connection

• Nonpersistent connection

• Both persistent and Nonpersistent

• None of these

The drawback of checksum are

• Odd number of errors cannot be detected

• Vertical bit errors can be detected

• Both (a) and (b)

• None of these

What is the technique of merging inputs of many links onto one link called?

• Digitalizing

• Transmitting

• Multiplexing

• Tunneling