erlangA unit of measurement of traffic density in a telecommunications system. The erlang describes the total traffic volume of one hour, or 3600 seconds.
For example, 60 calls in one hour, each lasting 5 minutes, results in the following number of erlangs:
minutes of traffic in the hour = number of calls x duration
minutes of traffic in the hour = 60 x 5
minutes if traffic in the hour = 300
hours of traffic in the hour = 300/60
hours of traffic in the hour = 5
traffic figure = 5 erlangs
Network designers use the erlang to understand traffic patterns within a voice network and use the figures to determine how many lines are required between a telephone system and a central office or between network locations.
Erlang calculations are further broken down as follows:
- Erlang B -- the most commonly used traffic model. Erlang B is used to work out how many lines are required if the traffic figure during the busiest hour is known. This model assumes that all blocked calls are cleared immediately.
- Extended Erlang B -- similar to Erlang B, this model can be used to factor in the number of calls that are blocked and immediately tried again.
- Erlang C -- this model assumes that all blocked calls are queued in the system until they can be handled. Call centers can use this calculation to determine how many call agents to staff, based on the number of calls per hour, the average duration of class and the amount of time calls are left in the queue.
Experts believe that Apple Pay and other competitive payment systems will be far more secure than cards, even cards equipped with EMV chips. Read More »Internet of Things Shaping IT's Future
To make the IoT both work and pay off, IT is juggling upgrading and building app-centric networks, mapping out new data center architectures and... Read More »What You Don't Read Can Hurt You
Does this sound familiar? An online service promises to help your small business cut costs, increase productivity, make your coffee and walk your... Read More »
The trend for the past two years has been for shoppers to spend more online during the holiday season. How do you typically shop for holiday... Read More »How to Create a Desktop Shortcut to a Website
This Webopedia guide will show you how to create a desktop shortcut to a website using Firefox, Chrome or Internet Explorer (IE). Read More »Flash Data Storage Vendor Trends
Although it is almost impossible to keep up with the pace of ongoing product releases, here are three recent highlights in the flash data storage... Read More »
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »