MIS435–Transmission Rate of Information Bits (TRIB) Exercise

Ethel Netis the Network Manager for a regional commercial nurseynamed Plant‘em Now. Sheis trying to make a decision between addingtraffic from a 64Kbps circuit onto an existing 256Kbps circuit (eliminating the slower circuit), or combining traffic from both onto a new 512Kbps circuit(eliminating both the 256K and 64K circuits).

Given the following information, what is your recommendation to her?The organization’s threshold to upgrade a circuit is a utilization rate of 75%. Hint:calculate the TRIB and utilization of both circuits.Add both TRIB values together and determine the estimated utilization if the existing circuits are combined. Use the organizations requirements to determine whether Cut ‘em Now retains the 256K circuit, or upgrades to the 512K circuit.

TRIB Exercise:

K = # information bits per character

M = frame length in characters

R = data transmission rate in characters per second

C = overhead characters (non-information characters) per frame

P = probability a frame will require retransmission

T = time between frames in seconds

Given:

256Kbps Circuit

8 bit ASCII

Total frame length 1500 bytes

Data transmission rate 24kilobytesper second

Protocol administrative overhead 80 bitsper frame

Error rate is 15framesin every 1000frames

Time between frames 35milliseconds

64 Kbps Circuit

8 bit ASCII

Total frame length 1500 bytes

Data transmission rate 9200 characters per second

Protocol administrative overhead 10 characters per frame

Error rate is 10 frames in every 1000 frames

Time between frames 25 milliseconds

Answer the following questions:

1. 256K Circuit TRIB: ___________

2. 256K Circuit Utilization:__________________(Express as xxx.xx%)

3. 64K Circuit TRIB: ________________

4. 64K Circuit Utilization: _____________(Express as xxx.xx%)

5. Estimated Utilization For Combining Both Circuits:______________(Express as xxx.xx%)

6. Should Ethel keep the existing 256K circuit or upgrade to 512k?

*You will find helpful notes on the attachment