# MIS 435 – Transmission Rate of Information Bits (TRIB) Exercise

MIS 435 – Transmission Rate of Information Bits (TRIB) Exercise

Tia Won is the Network Manager for a regional surgical physician group named Cut ‘em Now. Tia is trying to make a decision
between adding traffic 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:
256 Kbps Circuit
8 bit ASCII
Total frame length 1500 bytes
Data transmission rate 32 kilobytes per second
Error rate is 15 frames in every 1000 frames
Time between frames 37 milliseconds
64 Kbps Circuit
8 bit ASCII
Total frame length 1500 bytes
Data transmission rate 8500 characters per second
Error rate is 10 frames in every 1000 frames
Time between frames 25 milliseconds
1. 256K Circuit TRIB: ___________
2. 256K Circuit Utilization:__________________
3. 64K Circuit TRIB: ________________
4. 64K Circuit Utilization: _____________
5. Estimated Utilization For Combining Both Circuits: ______________
6. Should Tia keep the existing 256K circuit or upgrade to 512k