WordNet (r) 3.0 (2006):

Erlang
    n 1: a unit of traffic intensity in a telephone system

The Free On-line Dictionary of Computing (30 December 2018):

Erlang

   1.  Agner Krarup Erlang.  (The other senses were
   named after him).

   2.  A concurrent functional language for large
   industrial real-time systems by Armstrong, Williams and
   Virding of Ellemtel, Sweden.

   Erlang is untyped.  It has pattern matching syntax,
   recursion equations, explicit concurrency, asynchronous
   message passing and is relatively free from side-effects.
   It supports transparent cross-platform distribution.  It has
   primitives for detecting run-time errors, real-time garbage
   collection, modules, dynamic code replacement (change
   code in a continuously running real-time system) and a
   foreign language interface.

   An unsupported free version is available (subject to a
   non-commercial licence).  Commercial versions with support are
   available from Erlang Systems AB.  An interpreter in
   SICStus Prolog and compilers in C and Erlang are available
   for several Unix platforms.

   Open Telecom Platform (OTP) is a set of libraries and
   tools.

   Commercial version (http://erlang.se/) - sales, support,
   training, consultants.  Open-source version
   (http://erlang.org/) - downloads, user-contributed
   software, mailing lists.

   Training and consulting (http://erlang-consulting.com/).

   E-mail: .

   [Erlang - "Concurrent Programming in Erlang", J. Armstrong, M.
   & Williams R. Virding, Prentice Hall, 1993. ISBN 13-285792-8.]

   3.  36 CCS per hour, or 1 call-second per second.

   Erlang is a unit without dimension, accepted internationally
   for measuring the traffic intensity.  This unit is defined as
   the aggregate of continuous occupation of a channel for one
   hour (3600 seconds).  An intensity of one Erlang means the
   channel is continuously occupied.

   (2003-03-25)