- What is the
bit pattern sent by
an idle BISYNC
sender ?
- A BISYNC sender wish to
transmit
the following data:
Header: 01111110 00010000 Message: 00000011 00010000 01111110 CRC code: 11111111 00010000
Give the BISYNC frame transmitted using character stuffing: (I already wrote 2 SYN characters for you in the answer)
00010110 00010110
- An HDLC sender wants to
transmit a HDLC frame
containing the following information:
Destination address: 01111110 Send sequence number: 111 Receive sequence number: 000 Poll bit is not set Data: 11111111 11111111 FCS: 01111111 01111111
Show the HDLC information frame of the sender before using bit stuffing (I already put a flag code in the answer for you):
01111110
Show the HDLC frame of the sender after using bit stuffing - provide your answer as follows:
- Copy the frame in the above answer into the box below
- Add the stuffed bits by writing the ^ symbol in the position where you will insert a 0 bit using the bit stuffing method
01111110
- A sender is using
Stop-and-Wait to
communicate with a receiver.
Suppose a frame with send sequence number = 1 is received correctly.
Show the response of the received in the figure:
Suppose a frame with send sequence number = 1 is received incorrectly.
Show the response of the received in the figure:
- The Stop-and-Wait protocol
was once very popular; but when
the bandwidth of the
network increased to
Mbps,
the Stop-and-Wait protocol
was abandoned.
This question will explore the reason why.
Around 1980's, we use modems to connect home PC to Emory's workstations
The transmission speed (= bandwidth) of a modem connection is 64 kbps (= 64,000 bps)
The one-way propagation delay between my house and Emory is 5 × 10-5 sec (I live about 15 km away)
Assume that there are no transmission errors (best possible case)
Suppose each data frame consists of 1000 bytes (= 8000 bits) and each ACK frame is 10 bytes (= 80 bits), compute the effective bandwidth utilization if the sender transmits continuously to the receiver
- The effective bandwidth utilization is the fraction of the available bandwidth that is used for data transmission (= transmitting data frames)
I.e.:
- What fraction/portion of the available 64 kbps bandwidth is used to transmit data frames
Answer:
- Around 1995,
the telecom companies introduce
high speed internet connections
of speeds of about 100 Mbps
(= 100,000,000 bps)
Assume that there are no transmission errors (best possible case)
Suppose each data frame consists of 1000 bytes (= 8000 bits) and each ACK frame is 10 bytes (= 80 bits), compute the effective bandwidth utilization if the sender transmits continuously to the receiver
In other words:
- What fraction/portion of the available 100 Mbps bandwidth is used to transmit data frames
Answer:
-
A sender and a receiver is using the
Stop-and-Wait protocol.
- How long will it take for the sender to completely transfer the file.
Show your derivation to get full credit.
The one-way propagation delay
between the sender and
receiver
is 1 msec.
The one-way propagation delay
from the receiver to
the sender is the
same as the
forward delay
The transmission data rate on the link is 1 Gbps.
Each data frame consists of 10000 bits and each ACK frame is 100 bits long. The sender needs to transfer a file of 1,000,000 bytes.
There are no transmission errors.