What is Erlang

Erlang is the unit for measuring the traffic of resources in telecom field.

If the Resources is used for 60 min in 1 busy hour than we can say that the there is 1 erlang traffic in that resources.
So 1 Erlang is the 100% usage of the ressources.
If You are getting 10 Erlang traffic in your node than simply u can say that u have 60 subscriber in that perticular node for last 1 busy hour and each subscriber talked for 10 mins.
If two operator in your company using the phone line for whole hour than u can say u have 2 Erlang traffic for that phone line.
So Erlang shows the demand of the resources.