maintenance people are getting bored...

Ulf Wiger <>
Fri Nov 8 12:45:18 CET 2002

I have to share this with you.

In the internal Ericsson publication "Kontakten"
("Contact"), there was an article about British Telecom's
Voice over ATM (VoATM) network (the largest of its kind in
the world). Some positive mention of the AXD 301 switch,
which as you know uses Erlang technology:
or ", "About Ericsson",
"Publications", "Kontakten på nätet" -- or "Contact Online")

(First, in Swedish, as the English translation doesn't seem
to be ready yet.)

  "Erfarenheterna hittills av driften av VoATM-nätet är
mycket goda. Den sammantagna nätlösningen och prestandan hos
Ericssons 60 Gb flertjänstväxel AXD301 klarar lätt kraven på
servicekvalitet och har hittills betytt att stillestånd helt
kunnat undvikas. Talkvalitet eller kvalitet hos erbjudna
tjänster har inte påverkats negativt.
  Vi har inte haft några problem med gränssnitt till andra
operatörer, mobila nät eller internationella växlar.
Faktum är att nätprestandan har varit så stabil att risken
är uppenbar att vår fältpersonal tappar kompetensen i

(My translation into English.)

  "The experiences sofar from running the VoATM network are
very positive. The complete network solution and the
performance of Ericsson's 60 Gb Multi-Service switch AXD 301
can easily cope with the requirements, and have meant that
it's been possible to completely avoid outages. Speech
quality or quality of offered services have not been
adversely affected.
  We haven't had any problems with interfaces to other
operators, mobile networks or international switches. The
fact is that network performance has been so stable that our
field personell risk losing their competence in maintenance
work." (says Geoff Robinson, British Telecom)

Mr. Robinson is probably not as worried as he may sound, but
the fact is that the network has behaved unbelievably well.

The ATM signaling, O&M and resiliency functions are all
written in Erlang. I contribute this as an indicator that it
is indeed possible to design robust, complex,
high-performance products using Erlang.  (:

... not that many on this list doubt that, I suppose, or
indeed have proven it on their own.

Ulf Wiger, Senior Specialist,
   / / /   Architecture & Design of Carrier-Class Software
  / / /    Strategic Product & System Management
 / / /     Ericsson Telecom AB, ATM Multiservice Networks

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